DRAFT

IARC Technical Report # 3

Report of the NABOS/CABOS 2005 Expedition

Activities in the Arctic Ocean

With support from National Science Foundation

National Oceanic and Atmospheric Administration Japan Agency for Marine-Earth Science and Technology

2

3

TABLE OF CONTENTS Page # PREFACE (I.Polyakov, IARC)………………………………. ……………….………........ I. NABOS-05 EXPEDITION IN THE NORTHERN LAPTEV SEA ABOARD THE

ICEBREAKER KAPITAN DRANITSYN (SEPTEMBER 2005)….………………………

7 9

I.1. INTRODUCTION (I.Polyakov and I.Dmitrenko, IARC)…………………………………… 11 I.2. RESEARCH VESSEL (I.Dmitrenko, IARC) .…………..………………………….......... 11 I.3. CRUISE TRACK (I.Dmitrenko, IARC)…………………………………………………... 14 I.4. SCIENTIFIC PARTY (I.Dmitrenko, IARC, and B.Ivanov, AARI)……..………………….… 15 I.5. ICE CONDITIONS (T.Alexeeva, AARI)……..………………………………………....... 16 I.6. OBSERVATIONS (I.Dmitrenko, IARC, and B.Ivanov, AARI)……..………………………. 19

I.6.1. METEOROLOGICAL OBSERVATIONS (P.Minnett and E. Key, UM)…………..... 21 I.6.1.1. Introduction………………………………………………………………… 21 I.6.1.2. Instruments………………………………………………………………… 22 I.6.1.3. Measurements ……………………………………………………………. 24

I.6.2. OBSERVATIONS OF AIR-ICE-OCEAN INTERACTIONS (I.Repina, IAF)………. 26 I.6.2.1. Introduction………………………………………………………………… 26 I.6.2.2. Instruments ………………………………………………………………. 27 I.6.2.3. Preliminary results…………………………………………………………. 27

I.6.3. ICE OBSERVATIONS (T.Alexeeva, V.Smolianitsky, AARI; K.Rollenhagen, AWI)….. 31 I.6.3.1. Background information…………………………………………………… 31 I.6.3.2. Objectives…………………………………………………………………. 31 I.6.3.3. Visual and satellite information…………….…………………………....... 31 I.6.3.4. Satellite ice observations and data processing…………………………… 34 I.6.3.5. Ice observations during ice station………………………………………... 35

I.6.4. OCEANOGRAPHIC OBSERVATIONS…………………………………............ 38 I.6.4.1. Background information (I.Polyakov, IARC, and D.Walsh, NRL)..…………… 38 I.6.4.2. Routine CTD Measurements and Water Sampling………………............. 40

I.6.4.2.1. Objectives (I.Polyakov and I.Dmitrenko, IARC).……………………… 40 I.6.4.2.2. Methods (I.Dmitrenko, IARC, and S.Kirillov, AARI)…………………… 40 I.6.4.2.3. Equipment (R.Chadwell, IARC, and M.Dempsey, OM).………………. 41 I.6.4.2.4. Preliminary Results (I.Dmitrenko, IARC; S.Kirillov and L.Timokhov,

AARI)……………………………………………………………….. 42

I.6.4.3. Lowered Acoustic Doppler Current Meter Observations (P.Lazarevich, FSU) …………………………....................................................

46

I.6.4.3.1. Introduction and Objectives .……………………………………… 46 I.6.4.3.2. Research Activities….…………………………………………….. 47 I.6.4.3.3. Results .…………………………………………………………. 48

I.6.4.4. Moorings Observations…..……………………………………………….. 50 I.6.4.4.1. Objectives (I.Polyakov and I.Dmitrenko, IARC).……………………… 50 I.6.4.4.2. Mooring Design and Equipment (R.Chadwell, IARC, and

M.Dempsey, OM)……………………………………………….. …. 51

I.6.4.4.3. Mooring Deployments (R.Chadwell, IARC, M.Dempsey, OM, and J. Hölemann, AWI) .……………………………………………………

52

I.6.4.4.4. Mooring Recovery (R.Chadwell, IARC, and M.Dempsey, OM)………. 57 I.6.4.4.5. Preliminary Results (I.Dmitrenko, H.Simmons, I.Polyakov, IARC;

S.Kirillov, and L.Timokhov ( AARI)……….…………………………… 59

I.6.5. CHEMICAL OBSERVATIONS (M.Nitishinskiy, AARI, and L. Anderson, GU)….…... 65 I.6.5.1. Objectives ....………………………………………………………........... 65 I.6.5.2. Methods and Equipment ....………...…………………………………….. 65

4

I.6.5.3. Preliminary Results……..……………………………………................... 66 I.6.5.3.1. Surface distribution………………………………………………... 66 I.6.5.3.2. Scatter distribution………………………………………………… 67 I.6.5.3.3. Transect along the Laptev Sea continental slope………………… 68 I.6.5.3.4. Transect across the Laptev Sea continental slope………………. 70 I.6.5.3.5. Distribution of total dissolved inorganic carbon (DIC) and pCO2…. 73

I.6.5.4. Preliminary conclusions…………………………………………………… 74 I.6.6. BIOLOGICAL OBSERVATIONS (C.Bouchard and L.Fortier, LU)…………………. 76

I.6.6.1. Objectives……………………………………………………………. 76 I.6.6.2. Methods and Equipment…………………………………………….. 77 I.6.6.3. Preliminary Results……………………………..…………………… 78

I.6.7. THE USE OF NATURALLY OCCURRING TH-234 AS A PROXY FOR POC FLUX IN THE ARCTIC OCEAN (K.Cochran, NYU, and J.Deming, UW)…………..

80

I.6.8. ABUNDANCE OF HETEROTROPHIC BACTERIA AND NANOFLAGELLATES IN THE LAPTEV SEA (K.Iverson, UT)……………………………………………

80

I.7. IARC SUMMER SCHOOL ABOARD KAPITAN DRANITSYN (V.Alexeev, IARC)…………………………………………………………….………………….

81

II. EXPEDITION TO THE WESTERN NANSEN BASIN ABOARD

R/V LANCE (SEPTEMBER 2005)……………………………………………………....

83

II.1. INTRODUCTION …………………………………………………………………….. 84 II.2. RESEARCH VESSEL .…………..………………………….………………………. 84 II.3. CRUISE OUTLINE……………..……………………………………………………... 85 II.4. SCIENTIFIC PARTY ..………………………………………………………………... 86 II.5. WEATHER AND ICE CONDITIONS .…………………………………….………….. 86 II.6. CTD OBSERVATIONS ………………………………………………………………. 86

II.6.1. Background information ………………………………………………………... 86 II.6.2. Methods…………………………………………………………………………. 87 II.6.3. Equipment .……………………………………………………………………... 88 II.6.4. Preliminary Results …………………………………………………………….. 88

II.7. RECOMMENDATION FOR FUTURE MOORING OPERATIONS ………………….. 93

III. CRUISE REPORT OF THE CABOS-05 EXPEDITION TO THE BEAUFORT SEA ABOARD CANADIAN COAST GUARD ICEBREAKER Louis S. St-Laurent , SEPTEMBER 2005………………………………………………………………………...

95

III.1. INTRODUCTORY NOTE…………………………..………………………………… 96 III.2. RESEARCH VESSEL AND CRUISE PLAN.………………………………………… 96 III.3. MOORING RECOVERY AND DEPLOYMENT.……………………………………... 98 III.4. CABOS MOORING DESCRIPTION…………………………………………………. 98 III.5. A PRELIMINARY LOOK AT MOORING DATA.……………………………………... 100 REFERENCES…….……………………………………………………………………….

103

Appendix 1: NABOS-05 Station List (I.Dmitrenko, IARC, and S.Kirillov, AARI)…………... 106Appendix 2: Summary table of locations at the beginning and end of each LADCP

cast (P.Lazarevich, FSU) ……………………………………………………. 123

Appendix 3: RV Lance cruise log (V.Ivanov, IARC)………………………………..…... 125Appendix 4: RV Lance Station List (V.Ivanov, IARC)…………………………………... 128Appendix 5: Abstracts of 2005 IARC Summer School aboard Kapitan Dranitsyn… 130

5

GLOSSARY: AARI: Arctic and Antarctic Research Institute, St.Petersburg, Russia AWI: Alfred Wegener Institute for Polar and Marine Research, Bremerhavn, Germany FSU: Florida State University, USA GU: University of Getteborg, Sweden IAF: Institute of Atmospheric Physics, Russian Academy of Science, Moscow, Russia IARC: International Arctic Research Center, University of Alaska Fairbanks, Alaska, USA IMS: Institute of Marine Sciences, University of Alaska Fairbanks, Alaska, USA IOS: Institute of Ocean Sciences, BC, Canada LU: Laval University, Quebec City, Quebec, Canada NYU: Marine Sciences Research Center, State University of New York, USA NPI: Norwegian Polar Institute, Tromsø, Norway OM: Oceanetic Measurement Ltd., Sidney, BC, Canada PTWC: Pacific Tsunami Warning Center, Hawaii, USA SRNHI: State Research Navigation and Hydrographic Institute, St.Petersburg, Russia UM: Rosenstiel School of Marine and Atmospheric Science, University of Miami, USA UT: Norwegian College of Fishery Science, University of Tromsø, Norway UW: University of Washington, Seattle, USA

6

7

PREFACE

During the last year, an important step was taken towards establishing an integrated

Arctic Ocean Observing System (iAOOS) in which our programs NABOS (Nansen and Amundsen Basins Observational System) and CABOS (Canadian Basin Observational System) both play an important role. Together with our partners from Russia, Norway, Germany, Sweden, USA, and Canada we have expanded our mooring-based and other observations in different parts of the Arctic Ocean (see map below). Our analysis of mooring-based records and oceanographic surveys provided evidence that the Arctic Ocean has entered a new warm state, with potential implications for melting of arctic ice. This climatically important information is used in our publication prepared jointly by scientists from AWI (Germany), NPI and GFI/UIB (Norway), APL/UW, NRL, IARC/UAF and IMS/UAF (USA), and AARI (Russia). This joint work was a wonderful test of our ability to work together. For graduate students and early career scientists IARC, in cooperation with LU (Canada) and the AARI and IAF (Russia), presented a summer school program titled "Climate Change in the Arctic Ocean," which was held aboard the Russian icebreaker Kapitan Dranitsyn during its fourth scientific cruise to the Arctic Ocean. This effort of ours has received world-wide recognition. We have accumulated a great deal of experience deploying and recovering deep-sea oceanographic moorings and conducting multidisciplinary observations in the harsh Arctic conditions. Experienced international teams of scientists and technicians were assembled for these programs. All these accomplishments will be crucial to the future success of the project.

Igor Polyakov Project Principal Investigator

8

9

NABOS-05 Expedition

in the Northern Laptev Sea aboard the Icebreaker Kapitan Dranitsyn

(September 2005)

Igor Dmitrenko1, Boris Ivanov2, Vladimir Alexeev1, Tatiana Alexeeva2, Laif Anderson3, Caroline Bouchard4, Robert Chadwell1, Kirk Cochran5, Jody Deming6,

Michael Dempsey7, Kriss Iversen8, Louis Fortier4, Jens Hölemann9, Erika Key10, Sergey Kirillov2, Peter Lazarevich11, Peter Minnett10, Miroslav Nitishinskiy2,

Igor Polyakov1, Irina Repina12, Katya Rollenhagen9, Harper Simmons1, Leo Timokhov2, and David Walsh13

1 - International Arctic Research Center

University of Alaska Fairbanks Fairbanks, Alaska, USA

2 - Arctic and Antarctic Research Institute

St.Petersburg, Russia

3 - University of Getteborg Sweden

4 – Laval University

Québec City, Québec, Canada

5 - Marine Sciences Research Center State University of New York, USA

6 – University of Washington

Seattle, USA

7 - Oceanetic Measurement Ltd. Sidney, BC, Canada

8 - Norwegian College of Fishery Science

University of Tromsø, Norway

9 – Alfred Wegener Institute for Polar and Marine Research

Bremerhavn, Germany

10 - Rosenstiel School of Marine and Atmospheric Science

University of Miami, USA

11 – Florida State University USA

12 – Institute of Atmospheric Physics, Russian

Academy of Science Moscow, Russia

13 – Pacific Tsunami Warning Center,

Hawaii, USA

10

Scientific participants in the NABOS-05 cruise to the Laptev Sea, and summer school instructors and students, aboard Kapitan Dranitsyn

11

I.1. INTRODUCTION (I.Polyakov and I.Dmitrenko, IARC) NABOS (Nansen and Amundsen Basins Observational System) is one of the major International Arctic Research Center (IARC) initiatives. NABOS is a long-term program intended to provide a quantitative observationally based assessment of circulation, water mass transformations, and transformation mechanisms along the principal pathways transporting water from the Nordic Seas into the central Arctic Basin. The scope of the field problem clearly calls for international cooperation/coordination, a task commensurate with an international center. NABOS is currently conducted jointly by the IARC, the Institute of Ocean Sciences (IOS), Canada, the Arctic and Antarctic Research Institute (AARI), Russia, and the Norwegian Polar Institute (NPI), Norway in cooperation with Laval University (LU), Canada, University of Washington (International Arctic Buoy Project), and Alfred Wegener Institute (AWI) for Polar and Marine Research, Germany. The primary monitoring tool of the NABOS program is the series of moorings placed at carefully chosen locations around the Arctic Ocean. Time series obtained from these moorings will allow separation of synoptic-scale signal (e.g., eddies, shelf waves) from longer-term climatic signal. Located along the major pathways of water, heat, and salt transport, such moorings capture climatically important changes in oceanic conditions. The NABOS moorings operate for one year at a time, with replacement every year. A gradual increase in the number of moorings is planned, from two deployed in summer 2002, to the full-scale monitoring system after several years.

This report describes field research during the oceanographic cruise NABOS-05 aboard the icebreaker (I/B) Kapitan Dranitsyn in September 2005. The overarching goal of the 2005 field program was to characterize the oceanographic, ice, and biochemical conditions in the northern Laptev Sea along with mooring deployments and recovery.

I.2. RESEARCH VESSEL (I.Dmitrenko, IARC)

The Russian I/B Kapitan Dranitsyn (Figure I.2.1) has been chartered by the University of Alaska Fairbanks to carry out oceanographic research over the continental slope of the Siberian Arctic shelf. The ship is under the operation of the Murmansk Shipping Company located in Murmansk, Russia. I/B Kapitan Dranitsyn is a powerful conventionally propelled ice breaker, constructed in 1982. It was intended for working in the conditions of the Northern Sea Route and the Baltic Sea. The vessel was built at Wartsila Shipyard, Helsinki, Finland; on December 2, 1980 she was accepted by the crew and registered under Russia’s flag. In 1994 the icebreaker was remodeled in Finland; later she was reequipped for passenger operations. In 1999 she was updated in Norway and got a passenger vessel certificate. The icebreaker main technical characteristics are presented in Table I.2.1.

The ship may be navigated from two positions on the bridge and from an aft auxiliary bridge (ice can also be broken when travelling stern-first). An air curtain system is applied to assist ice-breaking (air at 0.8 kg cm-2 is discharged through vents from forward to amidships 2 m above the keel). Ice friction is reduced by polymeric coatings on the ice skirt. A cushioned stern allows close towing when vessels are being assisted through ice. Pumps can move 74 tons of water a minute between ballast and heeling tanks. Fresh water is provided from a vacuum distillation apparatus heated by exhaust gasses, which is supplemented by a reverse osmosis apparatus. A maximum of 80 tons a day can be produced. Two helicopters can be carried to assist ice navigation. Safety equipment includes 4 fully enclosed life-boats and 4 inflatable life rafts (total capacity 264 persons). The fuel consumption rate is shown in Table I.2.2. The icebreaker is equipped with 3 deck cranes. Two forward cranes can lift 3 tons each, and one at the helicopter deck lifts up to 10 tons.

12

Figure I.2.1: Icebreaker Kapitan Dranitsyn on NABOS-02 cruise in the northern Laptev Sea.

Table I.2.1: The main technical characteristics of I/B Kapitan Dranitsyn Displacement 15000 t (full load) Draft 8.5 m Breadth 26.75 m Length 121 m (waterline), 132.4 m (overall) Height 48.7 m Main engines 6 Wärtsilä-Sulzer 9 ZL40/48 Diesel sets developing 18.5MW (24 200

horse power) which drive 6 AC generators Propulsion 3 twin DC electric motors, each producing 5400 kW in either direction

turn the 22m long propeller shafts (one spare shaft is carried) Propellers 3, fixed pitch, 4.3 m diameter with 4 hardened steel blades turn at

about 110 to 200 rpm. Spare blades are carried which can be deployed at sea

Auxiliary power 5 alternating current generator sets developing 730kW (2200 horse power)

Fuel IFO-30 for main diesel sets, MGO for auxiliary generator sets Fuel storage 2800 ton IFO-30 and 600 ton MGO Hull thickness 45 mm where hull meets ice (the ice skirt) and 22-35 mm elsewhere Speed Full: 19 knot (35.2 km/h) with 6 engines; cruising speed: 16 knot (30

km/h) in calm open water; ice 1.5 m thick may be broken at 1 knot (1.8 km/h), 3 m has been broken by repeated ramming.

Ice class KM*LL3 A2 Operating range 10 500 nautical miles (19 500 km) at 16 knot (30 km/h) Anchors 2 weighing 6 tons each, with 300 m chains, and one spare Crew and passengers

60 and 102

13

Table I.2.2: Fuel consumption of I/B Kapitan Dranitsyn. Data provided by Murmansk Shipping Company Consumption for main diesel sets (IFO-30) Additional consumption (IFO-30)

Number of Diesels

Fuel Consumption (tons/day)

Air Temperature (grad. C)

Fuel Consumption (tons/day)

1 15.6 +15 2.5 2 31.2 +5 3.5 3 46.8 -10 5.0 4 62.4 -30 6.0 5 78.0 Site Consumption Consumption Rate MGO/IFO 6 93.6 4 ton/day 1/25

Figure I.2.2: LEBUS double-drum oceanographic winch on the helicopter deck of I/B Kapitan Dranitsyn (photo by Robert Chadwell, IARC).

A LEBUS double-drum electric oceanographic winch (Figure I.2.2) manufactured by LEBUS

Engineering International Ltd., England was additionally deployed on the helicopter deck of the icebreaker in September 2003 in order to operate the conductivity/temperature/depth (CTD) profiler, biological nets and trawl and to deploy/recover the moorings. Winch electric motor power is 7.3 KW. Each drum capacity is 3500 m of 0.3-inch cable. The left drum is used only for mooring recovery. The right drum with spooling mechanism contains the mechanical cable of 3000 m length to carry the CTD probe, nets and trawl. A HAWBOLDT C15-40 horizontal capstan manufactured by HAWBOLDT Industries (1989) Ltd., Canada was placed near the LEBUS winch in September 2004 (Figures I.2.3 and I.2.4). The capstan is equipped with 11.2 KW two speed Toshiba electric motor, and is used for mooring deployment/recovery. The horizontal drum diameter is 40’’.

14

Figure I.2.3: HAWBOLDT C15-40 horizontal capstan on the helicopter deck of I/B Kapitan Dranitsyn (photo by Robert Chadwell, IARC).

Figure I.2.4: CTD/Rosette winch and mooring capstan site position on Deck 4 are shown by red rectangles.

I.3. CRUISE TRACK (I.Dmitrenko, IARC) I/B Kapitan Dranitsyn left Kinkiness Harbor, Norway on 6 September 2005 and returned on

27 September 2005. The research area was over the continental slope of the Laptev Sea and the adjacent Eurasian Basin (Figure I.3.1). CTD profiles were carried out along three transects across the continental slope in the western, central and eastern Laptev Sea and along transects approximately orientated along the continental slope. The survey and mooring deployments within the Russian Exclusive Economic Zone were authorized by the Russian Ministry for Education and Science. On the way to the research area the icebreaker passed through the Barents and northern Kara seas and entered the Laptev Sea northward of Cape Arktichesky on September 10, 2005 where the scientific operations began. Having completed the major goals of the cruise on 20 September, the icebreaker left the Laptev Sea through the Vilkitsky Strait on 22 September (Figure I.3.1).

15

Figure I.3.1: NABOS-05 cruise track, 09/06/2005-09/27/2005. I.4. SCIENTIFIC PARTY (I.Dmitrenko, IARC, and B.Ivanov, AARI)

# Name Country Position Affiliation International Expedition Team

1 Dmitrenko, Igor USA Chief Scientist University of Alaska Fairbanks 2 Akimova, Anna Germany PhD Student Alfred-Wegener Institute 3 Barber, David Canada Scientist/ Instructor Univeristy of Winnipeg, Manitoba 4 Beliveau, Ian Canada Mooring Technician Oceanetic Measurement Ltd. 5 Bouchard, Caroline Canada Master Student Laval University 6 Chadwell, Robert USA Mooring Technician University of Alaska Fairbanks 7 Cochran, James USA Scientist/ Instructor State University of New York 8 Deming, Jody USA Scientist/ Instructor University of Washington 9 Dempsey, Michael Canada Mooring Technician Oceanetic Measurement Ltd. 10 Fortier, Louis Canada Scientist/ Instructor Laval University 11 Galley, Ryan Canada PhD Student University of Winnipeg, Manitoba 12 Holemann, Jens Germany Scientist/ Instructor Alfred-Wegener Institute 13 Lazarevich, Peter USA Scientist Florida State University 14 Minnett, Peter USA Scientist/ Instructor University of Miami 15 Rollenhagen, Katja Germany PhD Student Alfred Wegener Institute 16 Simmons, Harper USA Scientist/ Instructor University of Alaska Fairbanks 17 Sweet, David England Mooring Technician

Russian Expedition Team 18 Ivanov, Boris Russia Co-Chief Scientist Arctic and Antarctic Research Institute 19 Abramova, Ekaterina Russia Scientist Delta Lena Reserve 20 Alexeeva, Tatyana Russia PhD Student Arctic and Antarctic Research Institute 21 Bondareva, Elena Russia PhD Student Arctic and Antarctic Research Institute 22 Chernousova,

Anastasia Russia Master Student St. Petersburg State University

23 Churkin, Oleg Russia Scientist State Research Navigation & Hydrographic Institute

24 Dobrotina, Elena Russia Scientist Arctic and Antarctic Research Institute 25 Kirillov, Sergey Russia Scientist Arctic and Antarctic Research Institute 26 Koldunov, Nikolai Russia PhD Student Arctic and Antarctic Research Institute 27 Makhotin, Mikhail Russia PhD Student Arctic and Antarctic Research Institute 28 Nitishinsky, Miroslav Russia Scientist Arctic and Antarctic Research Institute 29 Petrov, Alexandr Russia Engineer Obukhov Institute of Atmospheric Physics 30 Repina, Irina Russia Scientist Obukhov Institute of Atmospheric Physics

16

31 Smirnov, Alexandr Russia Scientist Arctic and Antarctic Research Institute 32 Tishin, Maxim Russia Master Student St. Petersburg State University

Summer School Team 34 Alexeev, Vladimir USA Director University of Alaska Fairbanks 35 Alexeev, Genrikh Russia Instructor Arctic and Antarctic Research Institute 36 Artamonov, Arseny Russia PhD Student Moscow Inst. of Physics & Technology 37 Barry, Roger USA Instructor National Snow and Ice Data Center 38 Barz, Kristina Germany PhD Student Alfred-Wegener Institute 39 Byrkjedal, Oyvind Norway PhD Student University of Bergen 40 Cherry, Jessica USA PhD Student Columbia University 41 Dumont, Dany Canada PhD Student Laval University 42 Evans, Colleen USA PhD Student University of Washington 43 Golovnina, Ekaterina Russia PhD Student Shirshov Institute of Oceanology 44 Hoffman, Sharon USA PhD Student Woods Hole Oceanographic Institution 45 Iversen, Kriss Norway PhD Student University of Tromsø 46 Key, Erica USA Postdoc University of Miami 47 Koenig, Lora USA PhD Student University of Washington 48 Langen, Peter Denmark PhD Student University of Copenhagen 49 Langlois, Alexandre Canada PhD Student Univeristy of Winnipeg, Manitoba 50 Lanos, Romain Canada PhD Student Laval University 51 Mauritsen, Thorsten Denmark PhD Student Stockholm University 52 May, Ruslan Russia PhD Student St. Petersburg State University 53 Mokhov, Igor Russia Instructor Obukhov Institute of Atmospheric Physics 54 Phillips, Dallas Canada MS Student Southern Alberta Inst of Technology 55 Preobrazhenskaya,

Olga Russia PhD Student St. Petersburg State University

56 Razina, Viktoria Russia Interpreter Arctic and Antarctic Research Institute 57 Smith, Paul Canada PhD Student Carleton University, Ontario 58 Thompson, Alexandra USA Postdoc University of California at Berkeley 59 Tremblay, Bruno USA Instructor Columbia University 60 Tsukernik, Maria USA PhD Student University of Colorado Boulder 61 Vancoppenolle, Martin Belgium PhD Student Université Catholique de Louvain 62 Vasilyeva, Daria Russia PhD Student Arctic and Antarctic Research Institute 63 Volkov, Denis France Postdoc Collecte Localisation Satellite, Direction

d'Oceanographie Spatiale I.5. ICE CONDITIONS (T. Alexeeva, AARI)

Ice conditions in the Laptev Sea in 2005 were extremely propitious for navigation compared to the last three years. These light ice conditions may be explained by prevailing southern and southeasterly winds. In July-August a big ice discontinuity along the Severnaya Zemlya Islands was formed. Subsequently the ice massif, part of the cracked fast ice and icebergs all began to move to the northeast. At the same time the center of the Taimirskiy ice massif separated into two parts – northern and southern. The northern part drifted to the central Arctic and the southern part experienced substantial melting. Therefore, most of the cruise track passed through areas with open water or light ice.

The cruise track was divided into six zones with relatively uniform ice conditions noted A, B, C, D, E, and F (Figure I.5.1): Zone А: Northwestern part of the Laptev Sea. September 10 (81º42.29’N; 92º05.10’E) –September 10 (81º16.02’N; 101º24.27’E). Small floes of first-year ice were observed to the north of the Severnaya Zemlya Islands on September 10. Along the route total ice (one-year and multi-year) concentration averaged about 20-30% (Figure I.5.2, top left). Zone В: Edge of the Arctic ice massif, northeastern shore of the Severnaya Zemlya islands. September 10 (81º16.02’N; 101º24.27’E) - September 13 (80º20.91’N;101º47.44’E). This zone was the most interesting for ice observations. Most of the ship’s track passed through the compact ice (70-80%, Figure I.5.2, top right). One-year ice was dominant, with relatively minor

17

inclusions of multi-year ice and new-ice forms like slush, pancake ice and dark nilas (Figure I.5.2, second from the top left). In the northwest of the Laptev Sea the ship entered the ice massif aiming to find a stable ice floe for a daily ice camp. Camp was eventually set up on a big ice floe (81º11.96’N, 105º24.61’E) of one-year ice with snow depth of 15-20 cm, hummocks, ridges, and a lot of melt ponds. Later on the icebreaker moved towards the Severnaya Zemlya Islands where we found two polynas and many tabular icebergs (Figure I.5.2).

Figure I.5.1: Ice along the NABOS-05 cruise track. Sea-ice concentration on September 14, 2005 is shown by color. The ice chart was prepared using AMSR (Advanced Microwave Scanning Radiometer) AQUA satellite data from http://www.seaice.dk. Zone С: September 13 (80º20.91’N; 101º47.44’E) - September 13 (80º04.63’N; 106º29.36’E). The total ice concentration was about 70-80%. This zone is similar to Zone B, but in Zone C new ice forms prevailed (Figure I.5.2). Icebergs and bergy bits carried from the Severnaya Zemlya Archipelago were observed along the ship’s route (Figure I.5.2). Zone D: September 13 (80º04.63’N; 106º29.36’E) - September 14 (78º47.07’N; 113º20.15’E). A big (about 5x2 nautical miles) ice floe (presumably former fast ice) was observed on the route. This floe was transported, along with a lot of icebergs and bergy bits, from Shokalskiy Strait. Ice concentration was 70-80% with prevailing slush and dark nilas (Figure I.5.2). Zone Е: September 14 (78º45.77’N; 113º30.40’E) - September 14 (78º20.09’N; 125º08.45’E) and September 16 (79º49.40’N; 127º57.09’E) – to the end of the expedition. Open water. Zone F: September 14 (78º20.09’N; 125º08.45’E) - September 16 (79º49.40’N; 127º57.09’E). This zone is characterized by 50-60% concentration of ice. Small ice floes, extensively melted and with separated hummock forms, prevailed. During this two-day period one of the mooring stations was recovered (Figure I.5.2).

18

Zone A.

Zone B.

Zone B.

Zone B.

Zone B.

Zone C.

Zone C.

Zone D.

19

Zone F.

Figure I.5.2: Different ice conditions along the NABOS-05 cruise track.

I.6. OBSERVATIONS (I.Dmitrenko, IARC, and B.Ivanov, AARI) The NABOS-05 program included routine CTD and Lowered Acoustic Doppler Current

Profiler (LADCP) observations, water sampling, recovery and deployment of oceanographic moorings, hydrochemical, biological, ice and meteorological observations. Measurements made during the cruise NABOS-05 on I/B Kapitan Dranitsyn are described in Table I.6.1 and the operational map is shown in Figure I.6.1. The complete information about all research activities during the cruise is summarized in Appendix 2. Information in Table I.6.1 and Appendix 1 is presented in chronological order.

Figure I.6.1: Map of NABOS-05 operations.

20

Table I.6.1: Observations during the NABOS-05 cruise of the I/B Kapitan Dranitsyn

Station # Date Dd/mm

Time GMT Lat Lon Depth

m

CTD LADCP Rosette Net

Tow Moor.

Dep.

Moor.Rec.

KD0105 10/09 9:14 81°38.0’ 097°24.0’ 1100 X X X X X KD0205 10/09 15:36 81(15.0’ 101(10.2’ 1010 X X X X KD0305 10/09 22:00 81(02.0’ 105(19.4’ >2000 X X X X X ICE0105 11/09 01:30 81(12.0’ 105(24.6’ >2500 KD0405 11/09 12:06 80(56.3’ 104(46.0’ 2360 X X X X X KD0505 11/09 16:18 80(50.7’ 104(20.5’ 1600 X X X X X KD0605 12/09 8:20 80(47.5’ 103(48.2’ 1500 X X X KD0705 12/09 12:15 80(43.2’ 103(12.6’ 900 X X X KD0805 12/09 16:12 80(34.0’ 102(03.9’ 270 X X X X KD0905 12/09 22:32 80°21.8’ 101°18.8’ 185 X X X X X X KD1005 13/09 08:55 80(04.1’ 106°36.5’ 1500 X X X KD1105 13/09 15:45 79°23.1’ 109°32.3’ 1650 X X X X X KD1205 13/09 22:21 78°47.1’ 113°14.7’ 1530 X X X X X KD1305 14/09 4:24 78°14.0’ 116°49.9’ 1620 X X X X X KD1405 14/09 10:15 77°41.0’ 120°00.6’ 1450 X X X X X KD1505 14/09 15:35 77°32.0’ 122°56.2’ 1650 X X X X X KD1605 14/09 22:19 78°25.8’ 125°36.7’ >2000 X X X X X KD1705 15/09 22:20 78°57.0’ 126°03.5’ 2900 X X X X X KD1805 16/09 4:10 79º22.9’ 125°47.6’ 3100 X X X X KD1905 16/09 8:38 79º48.8’ 126°16.6’ >3000 X X X X X KD2005 16/09 16:34 79°49.8’ 129°19.0’ >3000 X X X KD2105 16/09 21:05 79°50.0’ 133°23.2’ 2000 X X X X X KD2205 17/09 3:02 79°49.9’ 137°48.2’ >2000 X X X X KD2305 17/09 8:06 80°25.6’ 140°27.0’ 1600 X X X X X KD2405 17/09 11:52 80°14.2’ 140°57.9’ 1710 X X X X X KD2505 17/09 15:15 80°01.7’ 141°47.8’ 1650 X X X X X KD2605 17/09 18:20 79°55.5’ 142°19.6’ 1330 X X X X X X X KD2705 18/09 2:33 79°35.2’ 142°24.1’ 1170 X X X X X KD2805 18/09 5:24 79°25.1’ 143°00.2’ 540 X X X X X KD2905 18/09 7:53 79°15.1’ 143°29.2’ 200 X X X X X KD3005 18/09 10:25 79°00.1’ 143°58.2’ 90 X X X X X KD3105 19/09 0:41 79°25.1’ 139°48.9’ 1820 X X X X X KD3205 19/09 5:30 79°00.0’ 137°40.8’ 1700 X X X X X KD3305 19/09 9:55 78°40.2’ 135°30.1’ >2000 X X X X X KD3405 19/09 15:35 78°29.7’ 132°58.1’ >2000 X X X KD3505 20/09 18:30 78°29.9’ 125°43.4’ 2400 X X KD3605 20/09 22:15 78°06.4’ 126°04.2’ 2000 X X X X X KD3705 21/09 2:58 77°44.1’ 125°59.7’ >2000 X X X X X KD3805 21/09 7:31 77°30.4’ 126°00.2’ 1770 X X X X X KD3905 21/09 11:20 77°20.4’ 125°59.2’ 1200 X X X X X KD4005 21/09 15:00 77°03.4’ 126°00.9’ 120 X X X X KD4105 21/09 20:40 76°44.5’ 126°00.9’ 120 X X X X X

21

I.6.1. METEOROLOGICAL OBSERVATIONS (P.Minnett and E.Key, UM)

I.6.1.1. Introduction As part of the NABOS-05 cruise a suite of instruments was installed to measure the surface

meteorology and sea-surface temperature. The two primary objectives that determined the choice of sensors were

1. to study the cloud radiative forcing at the surface over a wide range of sea-ice and cloud conditions, and

2. to provide data for a summer school project on the surface heat budget at a time when the ice is beginning to re-form in the fall.

The conditions experienced during the cruise were very different from those anticipated. There was very little ice, compared to previous years, and the ice edge had retreated far to the north (Figure I.6.1.1). With the exception of the short time when the ship was in ice near Severnaya Zemlya, the cloud conditions were overcast with very uniform low stratus. The sensors used are listed in Table I.6.1.1. The laptop computers used to control the instruments and log the data were installed in a cabin on Deck 9 (for ship deck schematic see Figure I.2.4).

Figure I.6.1.1: Daily sea ice concentrations along the sections of the track of the I/B Kapitan Dranitsyn along which measurements were made during NABOS 2005. The ice concentration data are derived from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) with a spatial resolution of 12.5 km. The color bar at top indicates the percent sea ice concentration along the track, while the color bar at the bottom is the bathymetry/elevation in the study region. A bottom bound of -2000 m was set to identify the continental shelf break, setting all depths greater than -2000 m to black.

22

Table I.6.1.1: Instruments installed on the Kapitan Dranitsyn for the NABOS 2005 cruise.

I.6.1.2. Instruments Weather Station This is a self-contained system that measures air temperature and humidity, wind speed and direction, surface air pressure, and longwave (λ ~ 3-30μm) and shortwave (λ ~ 0.3-3μm) incident radiation. The 2π radiometers are gimballed to reduce the effects of ship motion. The computer used for data logging is housed within the white tube below the wind vane. On the Kapitan Dranitsyn the weather station was mounted on the forward railing above the bridge (Figure I.6.1.2).

Figure I.6.1.2: The meteorological station installed above the bridge of

the Kapitan Dranitsyn.

Figure I.6.1.3: The portable radiation package fixed above the aft railing of the bridge of the Kapitan Dranitsyn.

Portable Radiation Package We also installed a PRP (Portable Radiation Package; Figure I.6.1.3; Reynolds et al., 2001) which measures spectrally-resolved incident solar radiation using a 7-band Multi-Filter Rotating Shadowband Radiometer (MFRSR; Harrison et al., 1994). From these measurements, we derive daylight, clear-sky aerosol optical thicknesses. The wave-lengths of the MFRSR are listed in Table I.6.1.2. The PRP also includes 2π radiometers to measure longwave and shortwave incident radiation.

Instrument Location Weather station Forward railing above bridge Infrared radiometer (ISAR) Side railing above the bridge Surface temperature float Deployed by hand from the foredeck All-sky camera Above bridge Ice-camera Side railing above the bridge GPS Antenna on front face of accommodation block

23

Table I.6.1.2: Central wavelengths of the narrowband (δλ ~10 nm) filters used in the MFRSR.

Wavelength (nm)

Trace Species

415 aerosol 500 aerosol,

ozone 615 aerosol,

ozone 673 aerosol,

ozone 870 aerosol 940 water vapor

All-Sky Camera The all-sky camera is a downward-looking video camera (web cam) mounted above a domed mirror (Figure I.6.1.4). The images were recorded by a laptop computer at 30 sec intervals during the sunlit part of each day for subsequent analysis by a trained meteorologist to determine cloud types and amounts.

Figure I.6.1.4: The All-Sky Camera on the aft railing of the bridge of the Kapitan Dranitsyn (left)

and an example of an image (right).

Infrared radiometer A new infrared radiometer, the ISAR (Infrared Sea surface temperature Autonomous Radiometer), was deployed for the first time in polar conditions aboard the Kapitan Dranitsyn. The unit was designed to measure accurate skin temperatures of the ocean and ice on board volunteer observing ships. It was mounted on the port side railing of Deck 9 (Figure I.6.1.5 left). For reasons that are not yet clear but are likely to be related to the power supply not delivering enough current to drive the instrument at low temperatures, it exhibited a series of failures and did not produce any useable measurements during this deployment. Surface temperature float A surface float was used to measure the sea-surface temperature (SST) at a depth of ~5 cm (Figure I.6.1.5 right). This is a safety helmet (hard hat) filled with hard foam and carrying a precision thermistor. It was deployed and recovered by hand from the portside of the ship, amidships, while the Dranitsyn was on station or drifting in ice-free conditions. The data were logged by a laptop computer using a Digital Multi-Meter.

24

Figure I.6.1.5: The ISAR mounted on the port railing of the Kapitan Dranitsyn (left) and the SST (hard hat) float (right), which carries a thermistor at a depth of ~5cm.

Ice camera A web-cam was deployed on the port railing to monitor the ice conditions (Figure I.6.1.6). The images were recorded by a laptop computer for subsequent analysis.

Figure I.6.1.6: The web-cam clamped to the port railing to monitor sea and ice conditions. I.6.1.3. Measurements

The time-series of meteorological variables are shown in Figure I.6.1.7. The wind speeds shown are apparent winds which include the contribution from the ship’s motion. Periods when the ship was on station are apparent because of lower wind speeds which are generally quite light, with speeds <5ms-1. The air temperature was close to 0oC, within 5K, for most of the cruise, with some extended periods when the air temperature was below the freezing point of sea water (-1.8oC). The insolation (SW) shows the expected strong diurnal variability, but on all days but one, the values indicate extensive cloud cover. Figure I.6.1.8 displays the measured insolation (black) and the calculated clear-sky surface insolation, derived using a value for

25

Figure I.6.1.7: Meteorological variables measured on the Kapitan Dranitsyn.

26

Figure I.6.1.8: Time series of insolation measured on the Kapitan Dranitsyn during the NABOS-

05 cruise (black). The red trace is the computed top-of-atmosphere insolation for the ship’s position, and the blue line is the clear-sky surface insolation calculated using an assumed

atmospheric transmissivity of 0.89.

atmospheric transmissivity of 0.89. This has been found in other studies to be a remarkably invariant value in Arctic leads and polynyas [Hanafin and Minnett, 2001; Key, 2004; Minnett and Key, 2006] and also over Antarctic sea ice [Key and Minnett, 2006]. In general the presence of clouds reduces the surface insolation by more than a factor of two with respect to the anticipated cloud-free value. In those cases where the sky was clear, the measured insolation is close to that expected for the canonical atmospheric transmissivity. An exception was seen on September 13, 2005, when the diurnal signature of insolation indicates that the sky was clear for most of the day, and at times the measured values exceeded the top-of-atmosphere solar radiation. This is a relatively rare effect and results from reflections from bright clouds enhancing the direct beam of the sun in a clear part of the sky. Additional enhancement can result from multiple reflections between the cloud base and a high albedo snow or ice covered surface. At the time of writing, the data are still being processed and analyzed, and the results will be the subjects of future publications.

27

I.6.2. OBSERVATIONS OF AIR-ICE-OCEAN INTERACTIONS (I.Repina, IAF)

I.6.2.1. Introduction The following objectives defined the design of our experiments and the choice of

instrumentation: • Analyze energy and gas exchange between atmosphere and surface using

measurements of turbulent, latent, and sensible heat fluxes, momentum, and carbon dioxide (CO2) fluxes in the subsurface layer of the atmosphere.

• Define the exchange coefficients in the aerodynamic bulk formulas, the surface roughness parameter, and gas exchange properties in respect to the type of the surface and meteorological conditions.

A suite of observations was carried out during the cruise: • direct measurements of temperature, horizontal and vertical components of wind speed

and humidity fluctuations above surfaces of various type (open water, ice of various structure and age, polynya). The data are used for calculation of heat and momentum fluxes, as well as roughness parameter of a surface. The measurements were carried out when the ship was moving and at ice stations;

• measurement of spatial distribution of surface temperature in the infrared (IR)-range.

I.6.2.2. Instruments For measurements the following equipment was used: • Sonic thermo-anemometer USA-1 (METEK Co.) that measures fluctuations of three

components of wind speed and temperature fluctuations with frequency of 20-50 Hz. • High frequency hygrometer (analyzer of air humidity) HMP-233 that allows the

measurement of relative humidity and air temperature. Frequency of measurements is 6 Hz.

• A GTH-175 digital thermometer was used to measure surface temperature. The range of measurement capability is from -199.9 up to +199.9°C with accuracy of 0.1°C.

• IR thermometer for remote air temperature measurements. The range of measurement capability from is from -10°C up to 300°C with resolution of 0.1°C and accuracy of 3 % difference from measured values.

When the ship was moving the equipment was placed on the bow using a meter boom

(height of measurements was 8 m) to minimize effect of vessel. At ice stations the measurements were carried out from a stationary 2m-high platform.

For calculation of fluxes both a direct method and an inertial-dissipation method were used. In the direct method the heat and momentum fluxes are determined from direct measurements of horizontal and vertical wind speed component fluctuations and temperature. The fluxes are calculated from their covariations. The inertial-dissipation method is based on the assumption of local isotropy and existence of inertial interval. The fluxes are estimated on turbulent energy balance and budget dispersions of temperature and specific humidity [Fairal and Larsen, 1986]. The roughness parameter was calculated following Grachev et al [1998].

I.6.2.3. Preliminary results Atmospheric turbulence characteristics obtained at two ice stations on September 14 and

17, 2005 are shown in Table1.6.2.1, where V is wind speed; D is wind direction; f is relative humidity; T is air temperature, оС; Tsur оС is surface temperature; H is sensible heat flux, all measured at 2 m height above the surface. LE is latent heat flux; τ is momentum flux; u* is friction velocity; T* is temperature scale; z/L is stability; z is height of measurements; L is Monin-Obukhov length scale; z0 is roughness length; uσ is standard deviation of wind speed (u-component); vσ is standard deviation of wind speed (v-component); wσ is standard deviation of

28

wind speed (w-component); tσ is standard deviation of temperature; CD is Drag coefficient; CH is sensible heat transfer coefficient; CE is latent heat transfer coefficient.

At the ice station a positive stratification of atmosphere close to neutral was observed. The

surface was composed of 90% one-year ice and 20% hummock (average hummock height was 0.5 m). On the airflow (upwind) side there was a hummock ridge. The sensible and latent heat fluxes were small, and the sensible heat flux was directed towards the surface. The CO2 fluxes and their variations were insignificant because ice has a strong impact on gas exchange. Increase of stability causes CO2 flux to approach zero. The onboard measurements were carried out on all routes of the icebreaker. Based on the measurement data the fluxes of sensible and latent heat, CO2, momentum and surface roughness parameter were calculated. During measurements weakly stable, weakly unstable, and neutral stratification was observed. In Figure I.6.2.1 the distribution of sensible heat fluxes is shown. Most-frequently observed values were close to zero. When the icebreaker was moving through ice, the air temperature was close to the ice surface temperature; where the ice cover was open, exposing sea water, an intensive energy exchange was observed.

Table I.6.2.1: Characteristics of turbulence in the lower atmosphere at ice stations (direct measurements). Height of measurements is 2 m. Time (GMT) V m s-1 D grad f % T air оС T ice оС FCO2

Mmol m-2 sec-1

6:40-9:30 5.6 87 92 0.1 -0.5 -6·10-5 H Wm-2

LE W m-2

τ

u* m s-1

T* оС

z/L

z0 m

-4 1.9 0.066 0.226 0.247 0.008 1·10-4

∗uuσ

∗uvσ

∗uwσ

∗Ttσ

CD

CH

CE

1.9 2.4 1.0 2.0 1.6·10-3 1.9·10-3 2.64·10-3

Figure I.6.2.1: The relative occurrence of sensible heat fluxes (H) measured over sea

surface.

29

Figure I.6.2.2: Sensible (top) and latent (bottom) heat flux variation along the NABOS-05 cruise track.

For example, on September 10-13 and 15-16 ice of 20-60% concentration was observed around the icebreaker, causing variability of sensible and latent heat fluxes as is shown in Figure I.6.2.2. The increase of fluxes on September 14, 18, and 23 is connected to increase of sea surface temperature and significant contrast between the air and water temperatures.

Direct measurement of sea surface temperature in ice-covered areas is labor-consuming. The application of contact methods is not always possible, and in the case of inhomogeneous surfaces (e.g. a combination of ice floes and openings) leads to large errors. The remote radiometric methods are labor-intensive, and results yield scattering of data. We attempted to restore the surface temperature using direct measurements of heat fluxes above the sea surface following Ivanov et al. [2003]. In Figure I.6.2.3 the air and sea temperature variations are shown. In ice-free conditions good agreement between measured and calculated values was found. Breaks in ice cover cause visible surface temperature variations. Surface temperature of water measured between ice floes agrees well with data obtained via contact measurements. The ice temperature is close to or less than the air temperature.

30

Figure I.6.2.3: Variations of air temperature (t, °C), calculated sea surface temperature (Ts) and

water temperature (Tw) from direct measurements.

In Figure I.6.2.6 the distribution of roughness parameter values is shown for measurements carried out above ice and open water along the icebreaker cruise track. The increase of values corresponds to sites with isolated ice floes of various concentration and structure.

Figure I.6.2.4: Roughness parameter variations along the NABOS-05 cruise track.

Measurements of СО2 fluxes were carried out both along the route of the icebreaker, and at

oceanographic stations. The measurements were carried out mostly above open water. In most parts of the Laptev Sea the ocean absorbed CO2 from the atmosphere. The flux changes its sign in the eastern part of the sea, where the significant salinity decrease indicates the presence of river water. The flux above ice is negative (from atmosphere to ice) and is close to 0 (-0.1:-0.3 mmol*m-2*day-1).

31

I.6.3. ICE OBSERVATIONS (T.Alexeeva, V.Smolianitsky, AARI, and K.Rollenhagen, AWI)

I.6.3.1. Background information Mean climatic ice concentration for September is shown in Figures I.6.3.1 and I.6.3.2.

Statistics is based on processing of 10-days averaged AARI air reconnaissance ice charts for 1950-1992 from the archive of the World Meteorological Organization.(WMO) project “Global Digital Sea Ice Data Bank” [Smolyanitsky, 2000]. These maps show that the first 10 days of September is a period of minimum ice extent and in 50% of cases (median) practically the entire Laptev Sea is ice-free except for the northern part and the part adjacent to Vilkitsky Strait. At the same time, the second 10-day period of September is in 50% of cases the time when ice formation begins. During the years with heavy ice conditions (quintile 75%) the Taimyr Ice Massif (TIM) is observed in the western part of the sea throughout the whole summer and the start of ice formation is shifted to the beginning of September. For the old ice the normal conditions are those with no significant extension of old ice in the Laptev Sea until the third 10-day period of September. For the years with heavy ice conditions, old ice expands towards the central part of the sea in the first 10-day period of September, and within the area of TIM during the second and third 10-day periods.

I.6.3.2. Objectives

The primary goals of work during the expedition were:

- to obtain sea-ice data necessary for interpretation of oceanographic and meteorological observations and to describe sea-ice variability, including its impact on navigation through ice;

- to map ice conditions using satellite passive microwave data from AQUA AMSR and shipborne data; and

- to measure ice thickness at the ice station using the electromagnetic profilometer EM31.

I.6.3.3. Visual and satellite information

Regular (September 10-16, 2005) ice observations including the area of observations (within the range of horizontal visibility and screen area of radar) and en route observations (within the zone of 1.5-2 hull lengths ahead and 3 hull widths on each side) were accomplished. For visual definition of en route ice thickness, a 2-meter stick attached to a board was used (Figure I.6.3.3 left). Regular shipborne radar measurements were used to estimate configuration of ice zones within the observational area (Figure I.6.3.3 right). Ship speed, course angle, time, and geographical coordinates were read from the radar screen.

The following ice cover parameters were observed:

- concentration (total and partial for all stages of development);

- stages of development and forms (according to stages or predominance);

- stages of melting;

- hummock and ridge concentrations;

- ice pressure;

- surface contamination concentration;

- predominant ice thickness (en route only);

- predominant snow height (en route only) and concentration; and

- existence and orientation of openings (leads, cracks) in the ice cover.

32

September, 1-10

Median quantile 75% September, 11-20

Median quantile 75% September, 21-30

Median quantile 75%

Figure I.6.3.1: Mean climatic sea ice concentration in three 10-day periods in September based

on AARI air reconnaissance ice charts for 1950-1992.

33

September, 1-10

Median quantile 75%

September, 11-20

Median quantile 75% September, 21-30

Median quantile 75%

Figure I.6.3.2: Mean climatic multi-year ice concentration in three 10-day periods of September based on AARI air reconnaissance ice charts for 1950-1992.

34

Figure I.6.3.3: Photos of the ice measurement stick (left) and regular radar (right). I.6.3.4. Satellite ice observations and data processing

Mapping of ice conditions was carried out using satellite AQUA AMSR, DMSP (Defense Meteorological Satellite Program) SSM/I (Special Sensor Microwave/Imager) and ENVISAT data, obtained daily from the Danish Technical University (DTU, http://www.seaice.dk). Seven ice charts were compiled during the period of September 10-17, 2005. These ice charts were compiled using 6 km resolution ice concentration imagery from AQUA AMSR, based on the hybrid DTU algorithm to retrieve the ice total concentration. Coloring and geographical transformation of initial imagery downloaded from the DTU server were carried out using the author’s software (by V.M.Smolyanitsky), while visualization and additional geographical location were accomplished using DTU-developed Java software available at the URLs http://www.seaice.dk and http://www.dcrs.dtu.dk. Comparative analysis of ice concentration from visual observations and satellite images shows significant differences near the ice edge, while the two datasets agree well in the open water and sea ice covered regions (Figure I.6.3.4).

Figure I.6.3.4: Mean ice concentration obtained by visual observations (visual data) versus mean ice concentration from satellite images (AMSR) for every 20 miles on the cruise track. The

line shows a linear regression, and the data are correlated at r=0.66.

35

I.6.3.5. Ice observations during ice station During the expedition measurements of ice thickness by EM31 were planned to be carried

out at three ice camps. However, we managed to organize only one ice camp, because the Laptev Sea was mostly ice-free and only in the northwestern part was a reliable ice floe found. This camp was situated on a big melting ice floe with numerous melt ponds covered by a 10-15 cm snow layer (81°11.958’ N; 105°24.614’ E).

Figure I.6.3.5: Ice thickness measurements by EM31 (photo by Jens Hoelemann, AWI) Technical/physical principle of EM31

At the ice camp, ice thickness measurements were made with an EM31. This instrument is an underground conductivity sensor, which was designed for geophysical exploration of the shallow underground. It can be used for sea ice thickness measurements as well. This is due to the insulating characteristic of sea ice (conductivity 0-60mS/m) and the conducting seawater (2400-2700 mS/m) below. It was found that the average underground conductivity decreases with increasing ice thickness. The underground electrical conductivity is measured by means of a low frequency electromagnetic (EM) field. The EM31 uses the frequency of 9.8 kHz. The EM31 has two coils, a transmitter coil and a receiver coil. The transmitter produces the first EM-field that penetrates through the ice. Below the ice the seawater induces eddy currents due to this field. These currents induce a second EM-field that penetrates upwards through the ice and reaches the receiver coil. The EM31 converts the received signal into an apparent conductivity. Its strength depends on the current ice thickness as well as the actual salinity. Therefore a calibration of the ice thickness function (see equation I.6.3.1) is essential.

Ice thickness determination/measurements The relation between the strength of the second EM-field and ice thickness h can be

described with an exponential function, with conductivity fc :

( )hkkkc f 210 exp −+= I.6.3.1

To determine parameters 10 ,kk and 2k a calibration with direct ice thickness measurements is required. Holes were drilled through the ice for tape measurements during the ice stations. Drs. D. Barber and B. Tremblay made these ice thickness measurements. We have also measured the conductivity at these ice holes. Seven of these observations were made. Unfortunately the ice thickness was less than 1.0 m at all drill positions. Parameters are determined by least square method with functional conductivity fc derived by directly measured

ice thickness (I.6.3.2) and from EM31 measured conductivity mc :

36

∑ →−=i

mf icic 22 ))()((χ minimum I.6.3.2

Finally, the following function derives the ice thickness:

( )⎟⎠⎞

⎜⎝⎛ −

−=1163

29.51ln854.01 mch I.6.3.3

Although the parameters of derived ice thickness function (I.6.3.3) and the EM31-manual are different, the ice thickness functions are very similar. Significant differences in ice thickness would occur for measurements under 100mS/m, which corresponds to an ice thickness larger then 3.5 m (Figure I.6.3.6), but ice thickness over 3.5 m could not be measured at the ice station. Therefore the ice thickness function given by equation (I.6.3.3) is valid for the taken samples only. The ice thickness measurement error is derived by assuming an error for the measured conductivity using 2χ , see equation (I.6.3.2):

1

2

−=

nmcχσ with 7=n I.6.3.4

The deviation for ice thickness is derived from simple error propagation:

( )( )mm cmc

mh kck

ch σσσ 1

02−−−=

∂∂

= I.7.3.5

Figure I.6.3.6: The ice thickness function derived from the calibration measurements and the least square method. The function in blue is given by the EM31 manual and the green function is derived from the ice thickness of the calibration measurements. The derived ice

thickness deviation is shown in red.

The ice thickness measurement error is shown by red in Figure I.6.3.6. The deviation is larger than 15% for conductivities larger than 950 mS/m and lower than 150 mS/m. This corresponds to ice thickness less than ~45 cm and more than ~2.90 m. For ice thickness measurements within these limits the deviation is not significant.

To determine ice thickness distribution and different ice thickness profiles we took more than 90 samples. The profiles were located parallel as well as perpendicular to the ship. Due to some refrozen melt ponds and the uncertainty to pass them measurements of thinner ice are lacking, as can be seen in Figure I.6.3.7. Almost all observations are within the determined error boundaries. Nevertheless, two modes of ice thickness were found. This distribution is valid for

37

this floe only. However, the floe was chosen for its representative characteristics in this region. The first mode corresponds to the undeformed or slightly deformed first year ice and the second to heavily deformed first year ice.

Figure I.6.3.7: Ice thickness distribution at the ice station on September 11, 2005. Total number of measurements is 95 (including the calibration measurements); the position of

the vessel: 81°11.958’N 105°24.614’E, in the Laptev Sea; the ice station was finished at 9 am GMT.

Figure I.6.3.8: Three ice thickness profiles taken parallel and perpendicular to the vessel. The profile shown in red is 30m distant and parallel to the vessel. It shows no strong

gradients in ice thickness changes and therefore can be seen as undeformed first year ice. The other two profiles, one parallel 60 m distant to the vessel (blue) and

other behind the vessel (green), show rapidly changing ice thickness that was most probably due to deformed first year ice.

The ice thickness profiles almost perpendicular to the vessel show no distinctive features. An ~150m-long profile taken behind the ship shows alternating thinner and thicker ice (Figure I.6.3.8). This could represent a strong deformed first year ice location of the floe, due to rafting or ridging. The two parallel profiles differ substantially (Figure I.6.3.8). The profile next to the vessel (~30 m apart) has thinner ice (mean = 1.1 m), shows no significant deformation, and can be classed as level first year ice. The second profile (mean = 1.5 m) which was ~60 m from the ship seems to be heavily deformed first year ice like the profile behind the ship.

38

The snow thickness was not determined, but Dr. B. Tremblay and his IARC summer school project students analyzed the snow in a small field on the floe and measured snow thickness. There the mean snow thickness did not exceed 20 cm. I.6.4. OCEANOGRAPHIC OBSERVATIONS

I.6.4.1. Background information (I.Polyakov, IARC, and D.Walsh, PTWC)

Observations made from ice-buoys, manned drifting stations, and satellites show that near-freezing surface waters, driven by surface winds and ice drift, exhibit a trans-polar drift from the Siberian Arctic toward Fram Strait [Rigor et al., 2002]. In the eastern part of the Eurasian Basin this flow merges with several branches coming from marginal arctic seas (the East Siberian and Laptev Sea branches, and further west the Barents Sea branch). The basic features of the circulation in the Nansen and Amundsen Basins are shown by blue arrows in Figure I.6.4.1. Nansen was the first to identify Atlantic Water (AW) in the Arctic Ocean during his drift on board the Fram in 1893-1896. Later observations provide evidence that the AW spreads cyclonically around the Arctic Basin, and is its major source of heat [Timofeev, 1960; Coachman and Barnes, 1963] clarify the properties of AW circulation. Aagaard [1989] used moored current measurements and hypothesized that major subsurface water transports occur in the form of narrow near-slope cyclonic boundary currents (Figure I.6.4.1, red arrows). Two major inflows supply the polar basins with AW - the Fram Strait AW branch and the Barents Sea AW branch [Rudels et al., 1994].

Figure I.6.4.1: Water mass circulation patterns in the Nansen Basin and adjacent arctic seas.

Surface and subsurface circulation shown by blue and red arrows respectively.

The Fram Strait branch enters the Nansen Basin through Fram Strait and follows the slope until it encounters the Barents Sea branch north of the Kara Sea, an area characterized by strong water-mass mixing and thermohaline interleaving. The two merged branches follow the Eurasian Basin bathymetry in a cyclonic sense, forming a narrow topographically trapped boundary current which flows at about 5 cm/s [Woodgate et al., 2001]. Near the Lomonosov Ridge the flow bifurcates, with part turning north and following the Lomonosov Ridge and another part entering the Canadian Basin [Woodgate et al., 2001]. Jones et al. [2001] stresses that the circulation in the deep waters (>1700m) has not been well determined.

39

Figure I.6.4.2: Low Halocline Water (LHW), Atlantic Water (AW), and Bottom Water (BW) on the typical vertical temperature and salinity distribution and T-S curve in the research area. The area of the northern Laptev Sea and adjacent Eurasian basin has complex water-mass

characteristics [Pfirman et al., 1994; Schauer et al.,1997; Schauer et al., 2002]. Atlantic Waters originating in Fram Strait are found between 150 and 800 m depth in this region (Figure I.6.4.2, left panel). Lower Halocline Water (LHW) lies at the base of the permanent halocline, occupying the region of T-S space defined by 34.0<S<34.5 psu, and temperature less than -1.0 °C [Woodgate et al., 2001]. Below the AW layer we find the the Bottom Waters (BW) with potential temperatures down to -0.95°C layers. The locations of these water masses in the T-S plane are shown in Figure I.6.4.2, right panel.

Little is known about temporal variability of thermohaline structure in the Eurasian Basin. An early attempt to quantify interannual variability of water-mass structure in this region is due to Quadfasel et al. [1993], who compared measurements from cruises in different years, finding significant year-to-year variability in the core temperature of the AW layer. However, because Quadfasel et al. compared measurements taken in different years and at different locations in the Nansen Basin, it is difficult to determine the extent to which their conclusions were influenced by aliasing of spatial and temporal variability, especially as the AW layer is known to cool dramatically as it flows through the Nansen Basin [Polyakov et al., 2003] emphasize that quantifying interannual variability in this region is substantially complicated by the large spatial gradients in the area. Processes which affect fresh-water content (e.g., freezing, melting, and riverine inflow) are of first-order importance to Arctic Ocean dynamics [Aagaard, 1989]. Large amounts of ice form in winter on the wide continental shelves on the periphery of the Arctic Ocean, in some cases producing dense, briny waters which flow off the shelves and significantly influence the T-S structure in the interior.

I.6.4.2. Routine CTD measurements and water sampling

I.6.4.2.1. Objectives (I.Polyakov and I.Dmitrenko, IARC)

40

The major objectives of the 2005 field experiments were: • to quantify changes in the structure and spatial variability of the main water masses over the continental shelf of the Laptev Sea and adjoined Eurasian Basin in 2005; and • to enhance understanding of the mechanisms by which the AW is transformed across and along the continental slope of the Eurasian Basin.

The hydrographic survey also provides important background information for processing of the long-term mooring data. I.6.4.2.2. Methods ( I.Dmitrenko, IARC, and S.Kirillov, AARI)

Over a 9-day period 41 CTD casts were made. Location and sampling time for the CTD casts are listed in Table I.6.1 and the locations are also depicted in Figure I.6.4.3.

Figure I.6.4.3: Scheme of CTD cross-sections and mooring sites for the NABOS-05 cruise. Black circles represent CTD and CTD/Niskin bottle stations; red, yellow, and blue circles are

mooring sites.

Cross-section A is located within the Russian Exclusive Economical Zone (REEZ) crossing the western Laptev Sea continental slope (Figure I.6.4.3). Measurements were carried out at the beginning of observations during September 10-12 along with two mooring deployments at positions of oceanographic station KD0505 (M5a) and KD0905 (AWI/OSL1).

Cross-section B extended across the REEZ and the Laptev Sea continental slope to the Arctic Ocean. The measurements along the northern part of this transect outside the REEZ (stations KD1605-1905) were carried out after successful recovery of mooring M1c on September 14 at station KD1605. The southern part of transect B is located within the REEZ and measurements at this part of the transect were carried out at the very end of observations during September 20-21. Stations KD3505-4105 were completed after mooring M1d had been deployed at the position of station KD3506 on September 20, 2005. The AWI/OSL2 shallow-water mooring deployment at the southern tip of transect B on September 21 finalized 2005 research operations.

41

Cross-section C (September 17-18, stations KD2305-3005) crossed the eastern Laptev Sea continental slope northward of the Novosibirskiye Islands where mooring M3a was recovered at September 17 near the position of station KD2605. It was redeployed 24 h later almost at the same position.

Cross-section D (stations KD0105, 0205, 0505, 1005-1505, 2605, 3105-3405, and 3805) connecting observational areas in the western, central, and eastern Laptev Sea was carried out along the continental slope of the Laptev Sea at ~1500m depth (Figure I.6.4.3).

Most CTD casts were made from the sea surface to a depth of 2000 m. Continuous CTD profiles were measured on the downcast. Water sampling was carried out by five-liter Niskin bottles at most stations (Table I.6.1). Sampling levels are shown in Appendix 1. The CTD winch was located on the helicopter deck of the icebreaker approximately 17 m forward of the three icebreaker propellers (Figure I.2.3). The draft of the icebreaker at the position of the CTD winch varies between 8.5 and 9.5 m. During CTD sounding the propellers were left running to keep the ship in the right position relative to the ice floes.

For data collection and processing, we used the SBE SEASOFT software package for Windows. Derived variables include pressure (in dbar), water temperature (in °C), and conductivity (S/m). Poor quality data from the upper water layer (usually 10-20 m) were removed. We mainly defined poor quality as higher than normal noise levels, spikes or jumps in the data due to the strong impact from the rotating propellers of the icebreaker in the upper water layer. To avoid the spikes in the calculated salinity (which depends on measured temperature, conductivity, and pressure) caused by misalignment of temperature and conductivity with each other we used an alignment procedure. The best alignment of conductivity with respect to temperature was obtained when the salinity spikes were minimized. Some experimentation with different approaches was required to find the best alignment; we finally determinated the advance of conductivity relative to temperature to be -0.4 sec.

Although in some cases the data were considered reliable one should take into account that the noise from propellers and ship draft can affect the data within the upper 20 m layer. The ocean depth was reliably measured by an Odom Hydrographic System dual frequency 12 & 210 KHz Eco-Sounder to a depth of 2000 m. Otherwise the depth information was obtained from navigational charts.

I.6.4.2.3. Equipment (R.Chadwell, IARC, and M.Dempsey, OM)

Continuous CTD profiles were made using a SEACAT Profiler SBE19plus. This system continuously measures conductivity, temperature and pressure at 0.25 m intervals in the vertical. The Seacat was calibrated just prior to the expedition (June, 2005). The technical description of sensors, according to the specifications of Sea-Bird Electronics, Inc., is presented in Table I.6.4.1. The full information can be downloaded from: http://www.seabird.com/products/spec_sheets/19plusdata.htm.

Table I.6.4.1: SEACAT Profiler SBE19plus technical information.

Sensors

Measure- ment

Range

Initial Accuracy

Typical Stability

(per month)

Resolution

Conductivity (S/m)

0 – 9

0.0005

0.0003

0.00005 (most oceanic waters) 0.00007 (high salinity waters) 0.00001 (fresh waters)

Temperature (°C) -5 to +35 0.005

0.0002 0.0001

Pressure 3500 m 0.1% of full scale range

0.004% of full scale range

0.002% of full scale range

I.6.4.2.4. Preliminary Results (I.Dmitrenko, IARC; S.Kirillov and L.Timokhov, AARI)

Early-fall water-column structure in the western and central Laptev Sea is characterized by a cold (-1.0÷1.8°C), and salty (30÷32 psu) surface layer, overlying a halocline in which salinity

42

increases to 34.85 psu at about 200 m (Figures I.6.4.4 - I.6.4.6). In the eastern Laptev Sea as well as over the outer shelf the surface water layer is warmer and fresher. Its temperature and salinity is 0÷2.5°C, and 26÷30 psu respectively (Figures I.6.4.5 and I.6.4.6).

Figure I.6.4.4: Salinity (blue) and temperature (red) vertical distribution at station KD1605. CTD data from SBE19plus. Right panel presents the zoomed upper 270 db of the left panel.

The surface mixed layer is about 20 m thick (Figures I.6.4.5 and I.6.4.6). The shallow

halocline centered at about 100-105 m depth is found above the thermocline centered at 180 m; this layer is believed to play a crucial role in insulating near-surface waters and overlying ice from upward heat fluxes.

Figure I.6.4.5: Cross-slope vertical temperature (°C) distribution in the upper 300 m layer from sections A (right), B (center), and C (right).

Over the western and central Laptev Sea in most cases the surface temperature is close to

the freezing point down to the depth of 60-80 m. The exceptions are represented only by stations situated in the vicinity of the continental shelf break, where a downward temperature increase of 0.3°C was observed right beneath the surface mixed layer down to the depth of 80 m (Figure I.6.4.5, left and center). In the eastern Laptev Sea the surface water temperature of 0÷2.5°C considerably exceeds freezing temperature.

43

Figure I.6.4.6: Cross-slope vertical salinity (psu) distribution in the upper 300 m layer from

sections A (left), B (center), and C (right). In deeper layers a temperature increase is observed; this vertical structure corresponds well

to previous studies (Figure I.6.4.2). A mid-depth temperature maximum marks the core of the AW, typically found between 120 and 260 m depth in this region (Figures I.6.4.4, I.6.4.7, see also Schauer et al. [1997] for more details). AW core salinity varies between 34.8 and 34.9 psu (Figures I.6.4.6, I.6.4.8, I.6.4.9, I.6.4.11-I.6.4.13). Beneath the AW core the temperature decreases to about -0.8°C while salinity slightly increases to 34.98 psu.

Figure I.6.4.7: Temperature (°C) distribution across the continental slope of the Laptev Sea along the cross-sections A (left) and B(right). 0°C isotherm (black line) traces the boundaries of

the AW layer.

The spatial variations of water temperature and salinity along the sections A, B, and C crossing the continental slope are presented in Figures I.6.4.7-I.6.4.9. Presumably, melting of ice and/or advection of fresh riverine waters southward of cross-section B and along cross-section C resulted in freshening of the surface water layer up to 26-30 psu (Figures I.6.4.6, I.6.4.8 right, and I.6.4.9 right).

44

Figure I.6.4.8: Salinity (psu) distribution across the continental slope of the Laptev Sea along the cross-sections A (left) and B (right).

The thickness of the AW layer, traced by the zero temperature isotherm, shows a strong

along-slope increase from 160 m (KD0105) to 900 m (KD1205), Figure I.6.4.10. The AW core deepened with the AW propagating along the slope from 110 m (KD0705, western Laptev Sea) to 280 m (KD2405, eastern Laptev Sea, Figure I.6.4.10). Across-slope the AW core is situated approximately 80 km northward of the shelf break near Severnaya Zemlya in the area of station KD0405, while in the central Laptev Sea it was found about 150-250 km northward from the continental shelf break between stations KD1605-1805 (Figure I.6.4.7 right). In the eastern Laptev Sea the AW core was traced about 100 km northward from the continental shelf break at station KD2405 (Figure I.6.4.9 left).

Figure I.6.4.9: Temperature (°C, left) and salinity (psu, right) distribution across the continental

slope of the Laptev Sea on cross-section C. 0°C isotherm (black line, left) traces the boundaries of the AW layer.

45

Figure I.6.4.10: Temperature (°C) distribution along the continental slope of the Laptev Sea on cross-section D. 0°C isotherm (black line) traces the boundaries of the AW layer.

Figure I.6.4.11: Salinity (psu) distribution along the continental slope of the Laptev Sea on cross-section D.

Figure I.6.4.12: Temperature versus salinity from cross-slope transects A (left): KD0405 (red), KD0605 (blue); B (center): KD1905 (red), KD1605 (blue), KD3805(black); C (right): KD2405

(red), KD2605 (blue), KD2805 (black). Thin solid black lines are isopycnals referenced to 300 db.

A step-like structure of vertical temperature distribution is commonly observed within the

AW. The typical thickness of temperature steps is about 20-25 m (Figure I.6.4.4, right). Similar steps were observed by Rudels et al. [1999] and in many other studies. It was hypothesized that these steps are formed as a result of the evolution of temperature isopycnical intrusions. These intrusions represented by small-scale temperature inversions are widely observed in the AW

46

layer (Figures I.6.4.4, I.6.4.5, I.6.4.12, and I.6.4.13). One may suggest that instability of the boundary that separates water masses of the same density but with different temperature and salinity may result in these intrusions. Our results clearly show the intrusions with higher temperature and salinity gradients are primarily situated in the western Laptev Sea (Figures I.6.4.5, I.6.4.6, I.6.4.14, left panels). Over the central Laptev Sea the intrusions became weaker. In the eastern Laptev Sea the step-like structure almost disappears (Figure I.6.4.5 right).

Figure I.6.4.13: Temperature versus salinity from along-slope transect D: KD0205 (red), KD1105(blue), KD1505 (black), KD3405 (green), and KD3105 (violet). Thin solid black lines are

isopycnals referenced to 300 db.

I.6.4.3. Lowered Acoustic Doppler Current Meter observations (P.Lazarevich, FSU) I.6.4.3.1. Introductions and Objectives

The Laptev Sea and the continental slope of the Siberian Arctic Shelf have been regions of primary interest due to evidence of enhanced mixing, thought to be caused by trapping of internal tides on the shelf. Numerical simulations of the internal tide field [Simmons, personal communication] suggest that strong barotropic to baroclinic conversion occurs here (Figure I.6.4.14).

Figure I.6.4.14: Modeled energy levels within the Laptev Sea associated with baroclinic conversion of the tide. The units are in log10 W/m2.

47

Dr. Harper Simmons (IARC) hosted the Florida State University contingent as well as supported our LADCP measurements. Additionally, two summer school students volunteered to assist with our program and made the around-the-clock sampling possible – Denis Volkov (Collecte Localisation Satellite, France), and Ruslan May (St. Petersburg State University, Russia).

I.6.4.3.2. Research Activities

There are several prerequisites for collecting meaningful LADCP profiles. First, the ADCP must be configured to run in ‘lowered’ mode. Second, the ADCP must be attached to a suitable frame (heavy and stable) for deep casts. Third, CTD measurements must be collected simultaneously. And fourth, navigational data must be collected during the cast.

On this cruise, the CTD measurements were made using a Sea-Bird SBE19+ rosette system and ADCP measurements were made using an RDI WHS300 ADCP mounted in a down-looking configuration. Figure I.6.4.15 shows the frame with mounted CTD (silvery tube at the bottom) and LADCP (yellow and black unit, at the bottom). Navigational (GPS) data were automatically recorded, but there were frequent gaps in the record. Instead of the continuous record with gaps, GPS fixes at the beginning and end of each cast are used. A table of these GPS coordinates is located at the end of this report, in Section 6. A total of 41 stations were made, of which 37 included LADCP measurements (see Table I.6.1). The depth at the stations varied from a maximum of 3100m to a minimum of 90m deep.

Figure I.6.4.15: The CTD and LADCP units mounted to the frame.

LADCP data were processed using the “LDEO” software. LDEO was originally written by Martin Visbeck while at the Lamont-Doherty Earth Observatory (LDEO) at Columbia University, and has been significantly revised and improved by Andreas Thurnherr (presently at LDEO). The software is a collection of Matlab scripts that read in the raw LADCP, CTD, and navigation data files, merges these data, and then computes velocity profiles and statistics. This is done separately for each CTD/LADCP cast. The latest version of the LDEO software, version 9, was made available by Andreas Thurnherr at the following ftp site: ftp://ftp.ldeo.columbia.edu/archive/ant/LADCP/Version_IX/.

The LDEO software is reasonably straightforward to work with and requires only a modest amount of tweaking to produce some results. However, the software is quite complex and involves many processing steps. There are many user-defined parameters which can be modified to improve the results. The LADCP data presented here are mostly based upon a ‘default’ implementation of the software; only a few parameters have been tweaked and these are noted below. For a complete description of the software, see the user’s guide, written by Andreas Thurnherr, located at the above ftp site.

48

Figure I.6.4.16: Horizontal velocity profiles with error bars (main panel), bottom-track

velocities (lower, left), instrument performance (middle, right), and CTD and ship drift during cast (lower, right).

I.6.4.3.3. Results

Summary plots from the LDEO software are shown below for the single station KD3105 (see Figure I.6.1 for the location) which is representative of the data that appear to ‘look’ good. Certainly, a more quantitative analysis of data validity is required.

Figure I.6.4.16 shows the main results from the cast – the vertical profile of east-west (u) and north-south (v) velocities and their associated errors (main panel). The mean velocity was 4 cm/s westward and 5 cm/s southward. The velocity error was about ± 2 cm/s and does not vary with depth. The smaller panel below indicates a non-zero near-bottom velocity of about 2 cm/s.

49

Figure I.6.4.17: Time-series of vertical-velocity profiles (top panel), depth (second), tilt

(third), heading (fourth), and battery voltage (fifth) during the cast. The bottom panels indicate beam performance and data quality for the four beams of the LADCP.

Figure I.6.4.17 shows the time series of vertical velocity (descent/ascent rate) and sensor

readings from the LADCP. Of special note is the tilt record, which indicates the orientation of the LADCP in degrees from vertical. On nine of the casts, tilt exceeded 15 degrees which results in a shorter effective range of the instrument and larger errors in the velocity calculations. Where tilt is substantial, the LADCP data should be suspect.

Figure I.6.4.18 shows the measured velocities, their scatter and the residuals. The left panels show the residuals, which is a valuable diagnostic for the performance of the software. The residuals should be evenly (randomly) distributed in time and distance from the instrument. If a non-random pattern is observed in the residual field, it indicates that the software is either not filtering out bad data properly or it is making an improper fit to the data.

While our trip to the Artic was not completely successful, we did achieve some good results with the LADCP. As noted earlier, the Kapitan Dranitsyn serves primarily as an eco-tourist vessel and we were not completely certain how well it would function in its role as a science

50

platform. In the end, we were pleased with the ship’s ability and the crew’s support. Our present plan is to attend the upcoming NABOS-06 cruise and contribute LADCP and microstructure observations to the science carried out on board.

Figure I.6.4.18: Processing Figure #3. This figure shows the eastward (upper panels) and westward (lower) velocities: residuals (left panels), measured velocities (middle), and the scatter

in the velocities (right).

Acknowledgements: The support and assistance provided by the Captain and crew of the I/B Kapitan Dranitsyn is greatly appreciated. The ship’s bosun, Pavil, was instrumental in getting our LADCP mounted to the CTD frame. Special thanks go to Dr. Igor Dmitrenko and our Russian hosts for sponsoring our group aboard the ship and providing us with the opportunity to make our LADCP measurements. We also wish to thank Dr. Harper Simmons for his enthusiastic support of our program and tireless dedication to the LADCP watch. We also had the support of two summer school participants, Denis Volkov and Ruslan May, who participated on watches and assisted with the data processing. Andreas Thurnherr provided us with the processing tools, know-how, and feedback on processing the LADCP data. His expertise was greatly appreciated. Financial support for this project was provided by the Office of Naval Research, grant number N00014-03-1-0307.

I.6.4.4. Moorings observations I.6.4.4.1. Objectives (I.Polyakov, and I.Dmitrenko, IARC)

The overall purpose of mooring observations is to provide observationally based information on temporal variability of water circulation and water mass transformation on the continental slope of the Laptev Sea. The major objectives were: • to quantify the structure and temporal variability of the main water masses over the

continental shelf of the Laptev Sea; and • to obtain detailed information about AW layer dynamics and seasonal variations.

51

I.6.4.4.2. Mooring design and equipment (R.Chadwell, IARC, and M.Dempsey, OM)

Mooring design and oceanographic equipment is presented in Figure I.6.4.19. The modified avalanche beacons were removed from the mooring design at the beginning of the field season 2005. The reasoning was that they would be needed only for a through-ice recovery. Since we are not equipped for through-ice recoveries we removed the instruments from our design as they sometimes became entangled during deployment and recoveries.

Figure I.6.4.19: NABOS moorings basic design and equipment. The McLane Moored Profiler (MMP) (Figure I.6.4.20) designed and manufactured by

McLane Research Laboratories, Inc. is the main component of NABOS moorings. The full technical information and description are available on http://www.mclanelabs.com.

52

Figure I.6.4.20: Sketch of McLane Moored Profiler, © of McLane Research Laboratories, Inc.

I.6.4.4.3. Mooring deployments (R.Chadwell, IARC, and M.Dempley, OM)

Five subsurface moorings were deployed during the NABOS-05 expedition. Moorings are designated first by location, for example M1, followed by a letter to designate the chronological order, i.e M1a, followed by M1b the subsequent year. Three NABOS moorings and two AWI/OSL moorings comprised the total mooring deployments during the year 2005 field season. The first mooring (M5a, Figure I.6.4.21) was a new deployment location just off the Severnaya Zemlya Islands. The second mooring deployment was a redeployment of M3 for the 2nd year and was therefore designated M3b (Figure I.6.4.22). Mooring location M2 was skipped again this year due to mooring unexplained disappearance in its first year of deployment. The last NABOS mooring deployment was a redeployment of the recently recovered M1. M1d (Figure I.6.4.23) is now in the beginning of its fourth year of deployment. The AWI/OSL moorings are shown in Figures I.6.4.24 (AWI/OSL1) and I.6.4.25 (AWI/OSL2).

We used anchor-first deployment in order to avoid towing the mooring through floating ice floes, which would place the towed array in danger of fouling on ice obstacles while the vessel maneuvers toward the target deployment site. Similarly, our moorings were designed with buoyancy located only at the top to prevent the array from surfacing during recovery with floats stranded under the ice on opposite sides of ice keels, thereby complicating retrieval.

53

Figure I.6.4.21: NABOS-05 M5a mooring design and equipment. Unfortunately, anchor-first operation also has disadvantages. Anchor-first deployments

require that the crane and rigging bear the weight of both the anchor and the 0.25-inch galvanized Nilspin wire. The tension on the wire hanging vertically over the side makes it more difficult to manipulate the wire while attaching instruments. Additionally, the tension poses greater risk of damaging the plastic wire jacket which is essential for the unencumbered vertical movement of our primary instrument, the MMP.

54

Figure I.6.4.22: NABOS-05 M3b mooring design and equipment.

55

Figure I.6.4.23: NABOS-05 M1d mooring design and equipment.

Switching to Kevlar line in components not needed by the MMP has proved to be advantageous so far. Kevlar can be used for several years whereas the recommended procedure for wire is to remove it from service after one year’s deployment. There are reduced

56

costs associated with using Kevlar in both replacement and shipping. Also, Kevlar line is relatively neutrally buoyant and significantly reduces the tension on deeper moorings. Disadvantages for Kevlar are vulnerability to fish bites which are generally acknowledged as low risk in Arctic environments and the possibility of the line being severed on sharp edges of pack ice during recoveries and deployments.

The purchase of a specially designed Hawboldt capstan (Figure I.2.3) alleviated the problems experienced with “pull down” or “cutting in” of the mooring wire during attempted deployments from our Lebus winch (Figure I.2.2) during last year’s NABOS-05 voyage.

Unanticipated large expanses of ice-free waters actually complicated deployments and recoveries. Planning was based on the assumption of relatively sheltered waters; however, accelerated drift rates and the rolling of the ship made deck operations complicated in open water with seas and swells.

The mooring team used Nobeltec Navigation Software and found it to be an excellent plotting and situational awareness tool.

Figure I.6.4.24: AWI/OSL1 mooring design and equipment.

57

Figure I.6.4.25: AWI/OSL2 mooring design and equipment.

I.6.4.4.4. Mooring recovery (R.Chadwell, IARC, and M.Dempley, OM)

Mooring M1c was recovered on September 15th, 2005 and turned around for redeployment. Recovery was delayed after the release command because the surface flotations became fouled on the keel of an ice flow. M1c took several hours to locate; all was on deck by 19:00 hrs UTC.

58

In last year’s cruise report we discussed moving the transponder to below the uppermost flotation device in anticipation of this specific scenario. The transponder shift proved essential to locating the mooring because the transponder was not shadowed by ice keels.

The movement of the M1c MMP profiler along the cable is depicted in Figure I.6.4.26. Data obtained from this mooring are summarized in Tables I.6.4.2 and I.6.4.3.

Figure I.6.4.26: Actual profiling track of NABOS-04 moored McLANE MMP Profiler (station M1c according to pressure sensor data.

Table I.6.4.2: Data from NABOS-04 mooring M1c recovered 15 September, 2005. Equipment Serial # Parameters Data

recovered Sampling rate

Actual depth(db)

Time of observations

RDI ADCP Current Yes 30 Minutes 54.5 09/15/04-09/15/05

Top Microcat CTD SBE 37 SM

1759 Conductivity Temperature Pressure

Yes 15 Minutes 60 09/15/04-09/15/05

McLane Moored Profiler

116765 Current Conductivity Temperature Pressure

Yes One profile per day

80 to 900 db 09/17/04-02/21/05

MMP FSI ACM Sensor

1756 Current Yes One profile per day

80 to 900 db 09/17/04-02/21/05

MMP Seabird 41CPs

856 Conductivity Temperature Pressure

Yes One profile per day

80 to 900 db 09/17/04-02/21/05

59

Table I.6.4.3: Data from NABOS-04 mooring M3a recovered 17 September, 2005. Equipment Serial # Parameters Data

recovered Sampling Rate

Actual depth(db)

Time of observations

Top Microcat CTD SBE-37SM

1653 Conductivity Temperature

Yes 15 Minutes 40 09/18/04-09/17/05

Microcat 37SM CTD

1615 Conductivity Temperature

Yes 15 Minutes 133 09/18/04-09/17/05

RDI ADCP 3845 Current Yes 1 Hour 132 09/18/04-09/17/05

PPS Sediment Trap

687 N/A 157

Microcat 37SM CTD

3049 Conductivity Temperature

Yes 15 Minutes 253 09/18/04-09/17/05

RCM 11 270 Current Temperature Conductivity Turbidity Oxygen Pressure

Yes 1 Hour 254 09/18/04-09/17/05

Microcat 37SM CTD

2864 Conductivity Temperature Pressure

Yes 15 Minutes 297 09/18/04-09/17/05

RCM11 267 Current Temperature Conductivity Turbidity Oxygen Pressure

Yes 1 Hour 825 09/18/04-09/17/05

PPS Sediment Trap

0021 N/A 828

I.6.4.4.5. Preliminary Results (I.Dmitrenko, H.Simmons, I.Polyakov, IARC, S.Kirillov, and

L.Timokhov, AARI)

The high quality of MMP-based temperature measurements is demonstrated by good agreement between the SBE19plus CTD profile carried out at station KD0704 just before the mooring deployment on September 13, 2004 and the first MMP profile made on September 17, 2004 (Figure I.6.4.27). Comparison of the first MMP salinity profile with the SBE19plus shipboard CTD salinity profile demonstrated a systematic difference, uniform across depth, of -0.046 psu (Figure I.6.4.27). This is despite the fact that both instruments were calibrated just before the cruise. However, the CTD cast taken at the mooring location on September 14, 2005 just before the M1c mooring recovery (station KD1605) did not show any salinity difference when compared with the MMP data at a depth of 1882 dbar where the instrument was resting (see Figure I.6.4.26). This suggests a sensor drift during MMP profiling. And, indeed, the MMP salinity record during the first 27 days after deployment exhibits a gradual salinity increase totaling 0.046 psu. This salinity increase was not accompanied by a corresponding temperature increase (Figure I.6.4.28). Thus, we attribute this salinity rise to the sensor drift. Consequently the first 27 days of the MMP salinity record were assumed to be erroneous and were eliminated from further data processing.

The high-quality MMP velocimeter record is confirmed by reasonable agreement between the uppermost MMP measurement (81 dbar) and the lower ADCP bin (48.5 dbar, Figure I.6.4.29).

60

Figure I.6.4.27: Vertical temperature (°C, red) and salinity (psu, blue) profiles at station KD0704 made by CTD SBE19pluse (09/13/2004) and MMP first profiles made on 09/17/2004

(temperature is shown by green, salinity is shown by black).

Figure I.6.4.28: Time series of daily salinity (red) and temperature (black) at 900 dbar depth

from the MMP profiler CTD, mooring M1c. Red shading marks time period where salinity record is suspicious.

Figure I.6.4.29: Zonal (left) and meridional (right) current components derived from lower ADCP bin taken at 48.5 dbar (top) and upper-most MMP measurement made at 81 dbar from

September 17, 2004 to February 5, 2005. Seven-day running means are shown by red lines.

61

The continuous temperature and salinity MMP records allow us to examine the temporal

variability of the entire AW layer over the first 160 days of observations (September 17, 2003 – February 21, 2005, Figure I.6.4.30).

Figure I.6.4.30: Temperature (°C, upper panel), salinity (psu, middle panel), and potential density (lower panel) within the Atlantic Water layer from September 18, 2004 to February 21,

2005 from MMP Profiler. 0°C Isotherm (black line) shows the boundaries of the AW layer.

As evident from the record, AW temperature does not vary significantly when compared with the previous years (see our previous Reports). Continuous gradual temperature increase until November 2004 was accompanied by AW layer thickening and deepening of the AW core by ~55 m (Figure I.6.4.30 top). Further, after exhibiting a decrease in temperature after September 2004, by the end of the observational period in February 2005 the AW layer showed signs of a gradual return to the thermal conditions of September 2004. Although there is no available MMP record between February and August 2005 the CTD cast taken after mooring recovery (station KD1605) has confirmed the return to the initial thermal conditions found on September 2004 (Figure I.6.4.35). This year’s MMP record complemented by CTD casts made before the mooring deployment and after mooring recovery (Figure I.6.4.35) also shows that the warming event started in February 2003 is still ongoing.

62

Figure I.6.4.31: Pressure (dbar), temperature (°C), and salinity (psu) derived from15-min

records from the uppermost position of SBE-37 at the M1a mooring (72 dbar depth). Seven-day running means are shown by black (pressure), red (temperature), and blue (salinity) thick lines.

Temperature and salinity changes from CTD SBE-37 (72 dbar, Figure I.6.4.31) are in

reasonable agreement with the MMP-based temperature and salinity variations from the upper-most MMP measurements (Figure I.6.4.30). Like in 2002-2004, the SBE-37 pressure sensor recorded well-defined tidal oscillations (Figure I.6.4.31 top). Tidal constants may be found in the NABOS-03 report [Dmitrenko et al., 2004].

Temperature and salinity records obtained from the M3a mooring fixed-depth SBE-37 CTD measurements made in 2004-05 from the AW layer (253 and 297 dbar) do not show significant trends (Figure I.6.4.32). Comparison of shipboard CTD casts taken at the mooring position before the mooring deployment in September 2004 and after its recovery a year later confirms this observation (Figure I.6.4.36). Rather, from mid-winter until mid-summer 2005 the AW layer became 0.5°C cooler and 0.1 psu fresher compared with conditions observed in September 2004 (Figure I.6.4.32 and I.6.4.33). The surface water layer was saltier and warmer in late fall - early winter (November-December 2004) compared with fresher and cooler conditions in January-May 2005 (Figures I.6.4.31 and I.6.4.32 top).

63

Figure I.6.4.32: Time series of 15-min

temperature (°C) from 40, 133, 253, and 297 dbar depths from SBE-37, mooring

M1b. Seven-day running means are shown by red line.

Figure I.6.4.33: Time series of 15-min salinity (psu) from 40, 133, 253, and 297 dbar depths from SBE-37, mooring M1b. Seven-day running means are shown by

blue line.

Figure I.6.4.34: (Left) Progressive vectors of daily currents from M1c mooring (100, 254, and

825 dbar) are shown from September 16, 2004 to February 21, 2005 by colored lines. In addition, current data derived from the ADCP 40 dbar record from September 16, 2004 to

February 21, 2005, and from February 22 to September 15, 2005 are shown by black and gray lines, respectively. (Right) Progressive vectors of daily currents derived from ADCP (44 and 98

dbar) and RCM-11 (254 and 825 dbar). Dots mark each 10 days.

64

The September 2004 - February 2005 M1c mooring MMP velocity record from the AW layer

demonstrates almost unidirectional along-isobath flow (~80°) with a mean speed of 3.5 cm/s (Figures I.6.4.34 left and I.6.4.35). A slight anticlockwise turn in the upper layer (100-200 dbar) coincides well with the depth of the pycnocline (Figure I.6.4.35). However, the year-long ADCP velocity record from the surface water layer at 10-40 dbar demonstrates substantial northward turn starting March 2005 (Figure I.6.4.34 left).

Year-long M3a mooring RCM-11s-based current records from the AW layer (254 and 825 dbar) exhibit almost along-slope (74°) flow with a speed of ~3.0 cm/s. Note that moorings deployed in 1995-96 at almost at the same position recorded the higher annual mean AW core velocity of 5.4 cm/s [Woodgate et al., 2001]. ADCP records derived from the upper water layer show a stronger current of up to 5.0 cm/s with a direction of 132° (Figures I.6.4.34 right, and I.6.4.36).

Figure I.6.4.35: M1c mooring vertical profiles of zonal (left) and meridional (right) currents averaged over the period of September 16,

2004 – February 21, 2005. The upper (12-48 dbar) and lower (80-890 dbar) portions were

derived from ADCP and MMP records, respectively. Data from the MMP profiler were averaged over 10 m bins. Gray shading shows

velocity standard deviations. Vertical temperature (red) and salinity (blue) profiles

were taken by shipboard CTD before the mooring deployment (left) and after the

mooring recovery (right).

Figure I.6.4.36: M3a mooring vertical profiles of zonal (left) and meridional (right) currents averaged over the period of September 18, 2004 – September 17, 2005. The upper (44-

126 dbar) portion was derived from the ADCP record. Levels of 255 and 825 dbar were

derived from RCM-11s. Gray shading shows velocity standard deviations. Vertical

temperature (red) and salinity (blue) profiles were taken by shipboard CTD before the mooring deployment (left) and after the

mooring recovery (right).

65

I.6.5. CHEMICAL OBSERVATIONS (M.Nitishinsky, AARI and L Anderson, GU)

I.6.5.1. Objectives

Climate change is a reality and the Arctic region is where it was first manifested. With one of the driving forces of climate change being the increasing CO2 load to the atmosphere, it is essential to assess feedbacks to this load. Arctic Ocean shelf seas are areas of carbon transformation by biological activity as well as air – sea flux of carbon dioxide. Hence, investigations of the chemical characteristics in these areas are important for understanding how the marine ecosystem functions. When studying the marine carbonate system two parameters, e.g. pH and alkalinity, are needed. Dissolved oxygen (DO) is necessary for respiration of living organisms. Nutrients (silicon, phosphates and nitrates) are essential minerals for primary production. The specific objectives of the NABOS chemical program were to fill gaps in existing observations of hydrochemical distributions in the Laptev Sea, leading to better understanding of the CO2 and nutrients fluxes and major water mass interactions in this region.

I.6.5.2. Methods and Equipment Water sampling was carried out using 5 l Nisken bottles (Figure I.6.5.1) at the standard

levels (10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 1000, 1500, 2000, 2500 m). Samples for DO and pH were taken first, followed by those for alkalinity and nutrients. The total sampling time was 25 – 40 minutes. DO and pH were determined in the ship laboratory within 2 – 3 hours after collection. The samples for alkalinity were processed in the laboratory at the Department of Chemistry of Gothenburg University (Gothenburg, Sweden) after the expedition. The nutrient concentrations were obtained in Russian-Germany Otto Schmidt Laboratory for Marine and Polar Research (AARI, St. Petersburg, Russia).

DO: Oxygen bottles of ~100 ml volume were used for the oxygen determination. The concentration of DO in seawater was analyzed onboard by using a classic Winkler titration method. The typical precision is ~2 μmol/kg. An ABU-80 autotitrator was used for the titration (Figure I.6.5.1).

pH: The spectrophotometric method of Lee and Millero [1995] was used for the pH determination utilizing an HITACHI U – 1100 spectrophotometer (Figure I.6.5.1 bottom left). For temperature correction of the formula, I.6.5.1 was used:

2)()( labTtBlabTtApHpH labTt −+−+= (I.6.5.1)

were t is in situ temperature (°C) and labT is temperature (°C) in the laboratory;

32 10))8(9806,63)8(505,32296,9( −−+−+−= labTlabT pHpHA 42 10))8(637,41)8(000,23916,3( −−+−+= labTlabT pHpHB .

For the correction of pressure effects, formula 1.6.5.2 was used:

APpHpH tPt += 0 (I.6.5.2)

where P is in situ pressure (atm).

30 10))8(0816,000282,0)35(0048,04242,0( −−−−−−=− tpHtSA .

The precision of this method is ±0.002.

Nutrients: Plastic 50 ml bottles were used for sampling. The samples were frozen to -20 °C immediately after sampling. The nutrient concentration in seawater was obtained using a colorimetric method and the SKALAR Sun plus System autoanalyzer (Figure I.6.5.1 bottom

66

right), using the SKALAR recommendations for determination of silicate, phosphate, nitrate and nitrite. The accuracy of the nutrient determination by this method is 5 %.

Alkalinity: Plastic 100 ml bottles were used for the alkalinity sampling. The alkalinity of seawater was obtained by a potentiometric titration method [Haraldsson et al., 1997]. The precision of the method is ±2 µmole/l.

The concentration of total dissolved inorganic carbon and pCO2 was calculated using pH, alkalinity, phosphate, salinity and temperature data from the expedition [Lewis and Wallace, 1998].

Figure I.6.5.1: The 24 Nisken bottle rosette on the helicopter deck of the icebreaker Kapitan Dranitsyn (top left), ABU-80 autotritator for determination of dissolved oxygen (top right),

HITACHI U – 1100 spectrophotometer for pH determination (bottom left), and SKALAR Sun plus System autoanalyzer for nutrient determination (bottom right).

I.6.5.3. Preliminary Results During the expedition, the 41 oceanographic stations occupied made up the work area, as

shown in Figure I.3.1. We performed 391 determinations of DO, 596 determinations of pH, 531 determinations of alkalinity and 567 determinations of nutrients.

I.6.5.3.1. Surface distribution The maximum surface water (10 m) concentration of DO (388 μmol/kg; 102.4 %) was

observed at station KD2005 and the minimum (355 μmol/kg; 100.1 %) at station KD2205. These stations were located in the northeastern part of the investigated area. The minimum surface water saturation of DO (99.1 %) was obtained at station KD1605 (Figure I.6.5.2).

The maximum pH value was observed at station KD0705, in the western part of the Laptev Sea (Figure I.6.5.2). This is a region where sea ice meltwater from the Taimyr area and Kara Sea influences the water properties. Furthermore the concentration of oxygen and nutrients in the region indicate intensive photosynthetic activity. Low pH values were observed in the eastern and southern regions, with the minimum pH value in the east at station KD3005.

The surface alkalinity distribution in the region under investigation does not show any specific trend; rather, several maxima and minima were observed along the cruise track. The

67

minimum surface water alkalinity was located at the northeastern station KD2205 (1695 μmol/kg), and the maximum alkalinity at station KD1605 (2080 μmol/kg) in the center of the study area (Figure I.6.5.2).

The silicate distribution in the surface water is shown in Figure I.6.5.3. The minimum concentration was found at the northwestern station KD0105, where concentrations did not exceed 3.3 μmol/kg. The maximum concentration (12.9 μmol/kg, station KD2305) was found in the northeastern part of the sea, an area that has low salinity because it is influenced by the Lena River runoff.

Figure I.6.5.2: Surface distribution (10 m) of the dissolved oxygen in μmol/kg, pH, and

alkalinity.

Figure I.6.5.3: Surface distribution (10 m) of silicate in μmol/kg, phosphate in μmol/kg,

and nitrate in μmol/kg.

The phosphate and nitrate surface concentration distribution is similar (Figure I.6.5.3). The highest concentration of these nutrients was located in the western and northeastern parts of the area under investigation. The maximum phosphate concentration (0.32 μmol/kg) was found at stations KD0105 and KD2305. The maximum surface nitrate concentration (1.16 μmol/kg) was found at station KD1005. The minimum phosphate concentration (0.01 μmol/kg) was found in the southern, shallow regions at station KD4105. The nitrate minimum (0.10 μmol/kg) was also found in the south, but at station KD1505.

I.6.5.3.2. Scatter distribution The scatter distribution of DO is shown in Figure I.6.5.4 in μmol/kg (left) and % (right). The

DO concentration range observed is 299.0 to 387.9 μmol/kg, while the degree of saturation

68

ranges from 83.2 to 103.9%. The maximum DO concentration is in the surface water. The sub-surface minimum DO saturation is located in the pycnocline layer, while the absolute minimum concentration is found in the AW. Below the layer of AW the DO concentration exhibits an intermediate maximum. Deeper than 1500 m the DO concentration is very stabile (about 300 μmol/kg).

Figure I.6.5.4: Scatter distribution of dissolved oxygen in μmol/kg (left) and degree of saturation in % (right).

The pH ranged between 7.82 – 8.09, with maximum values found at the surface. The minimum value was observed at the bottom of the shallow station KD4105. The scatter plot of pH is shown in Figure I.6.5.5 (top left). Maximum variability of pH is seen in the surface layer, from 0 – 50 m. At depths of 10-75 m the pH values decrease from 7.88 – 7.93 to 7.83 – 7.87 at 2000 m depth. In the AW layer some small maxima and minima in pH is observed, most likely caused by the temperature intrusions.

Alkalinity ranges from 1695 μmol/kg to 2315 μmol/kg (Figure I.6.5.5 top right). The alkalinity largely follows the sharp increase in salinity from the surface to a depth of

about 150 - 200 m (the bottom of the pycnocline). At greater depths the alkalinity shows a tendency to increase with depth, but remains in the interval 2295 – 2310 μmol/kg.

In the surface layer the silicate concentration is highly variable (Figure I.6.5.5 center left). The river runoff, ice melting, biology processes and wind mixing on the Laptev Sea Shelf all influence the surface silicate distribution in this part of the Arctic, resulting in highly variable concentrations. The silicate concentration in the area of investigation changed from 3.3 μmol/kg to 12.9 μmol/kg. Within the pycnocline relatively constant concentrations in the range 5.0 – 6.7 μmol/kg were observed. Deeper than the pycnocline, the silicate concentration increased with depth and at 2000 m values from 11.7 μmol/kg to 12.6 μmol/kg were found. In the AW layer the profiles of silicate show small maxima and minima as a result of interaction with waters at the continental slope, also manifested by the temperature intrusions.

The phosphate and nitrate concentrations are very low in the surface layer (Figure I.6.5.5 center right and bottom). Photosynthesis consumes nutrients, resulting in concentrations near to zero in the ice-free area of the Laptev Sea all through the summer period. ln the top 100 m the concentrations of phosphate and nitrate increase rapidly with depth. At 150 m depth the concentration range is from 0.47 to 0.83 μmol/kg for phosphate and from 5.1 to 7.7 μmol/kg for nitrate. Generally the nutrient concentration increases with depth with the maximum concentration of phosphate, 1.15 μmol/kg, observed at the bottom of station 20. The maximum nitrate concentration, 10.34 μmol/kg, was observed at the 1500 m depth of station KD1705.

I.6.5.3.3. Transect along the Laptev Sea continental slope Figure I.6.5.6 illustrates the schematic distribution of water masses at the transect along the

Laptev Sea continental slope. Three types of surface water masses were selected. The Western Surface water mass of the Laptev Sea shelf (WSSWMLSS) is formed on the Laptev

69

Sea shelf in summer. The ice melting and ground water flow off the Taimyr area are essential for the formation of the WSSWMLSS. The WSSWMLSS is characterized by a minimum concentration of silicate (< 5 μmol/kg), low concentration of phosphate and nitrate (0.15 – 0.25 μmol/kg and 0.05 – 0.50 μmol/kg respectively), low alkalinity (1800 – 2050 μmol/kg), high pH values (> 8.04) and high DO concentration (> 375 μmol/kg; > 100%).

Figure I.6.5.5: Scatter distribution of pH (top left), alkalinity in μmol/kg (top right), silicate in μmol/kg (center left), phosphate in μmol/kg (center right) and nitrate in μmol/kg (bottom).

70

Figure I.6.5.6: The scheme of water mass locations at the transect along the Laptev Sea continental slope.

The Eastern Surface Water Mass of the Laptev Sea Shelf (ESSWMLSS) is also formed on the Laptev Sea shelf. However, the ESSWMLSS is significantly influenced by river runoff from the Laptev Sea. The ESSWMLSS is characterized by low (minimum) salinity and silica concentration above 8.9 μmol/kg. In addition the concentration of phosphate and nitrate is low (about 0.25 and <1.00 μmol/kg, respectively), alkalinity is in the range of 1885 - 1905 μmol/kg, pH is in the range of 7.87-7.91 and the concentration of DO ranges between 355 – 370 μmol/kg (99 – 100%).

The Arctic Surface water masses (ASSWM) (Figure I.6.5.6) have low salinity, concentration of silicate lower then 8.9 μmol/kg, low phosphate concentration (about 0.2 μmol/kg) and low nitrate concentration (about 0.5 μmol/kg). The pH range is 7.90 – 7.95, alkalinity is 1960 – 2060 μmol/kg and DO concentration is about 370 μmol/kg (99%).

The Atlantic Layer water mass (AL) is located in the layer from the pycnocline to 600 – 1000 m. The Atlantic Layer water is identified by its temperature maxima. Important differences in the concentrations of nutrients, pH and DO in the western (1) and eastern (2) parts of the AL were observed (Figure I.6.5.6).

The properties along the transect are influenced by interaction/exchange with the Laptev Sea shelf and its continental slope (Figure I.6.5.7 top). In the AL the nitrate concentration was higher in the eastern part of the transect than in the western part. The same was also observed for the silicate and phosphate concentrations. The opposite pattern was observed for pH and DO, which had lower values in the eastern then in the western parts of this layer. The concentration range of hydrochemical properties in the AL was the following: silicate 6 – 8 μmol/kg; phosphate 0.60 – 0.95 μmol/kg; nitrate 5 – 9 μmol/kg; alkalinity 2200 – 2300 μmol/kg; and DO 308 – 330 μmol/kg (92 – 87 %). pH in this layer ranged between 7.85 – 7.95.

Two types of the water mass were selected in the bottom layer, both with high nutrients and alkalinity concentration and low pH and DO concentration. However, the Eastern deep water mass (Figure I.6.5.6) has lower oxygen concentration (about 305 μmol/kg), very low pH (< 7.85), higher nutrients concentration (phosphate > 1 μmol/kg; silicate > 8 μmol/kg; nitrate > 9 μmol/kg) and high alkalinity (> 2300 μmol/kg), compared to the other deep water mass.

I.6.5.3.4. Transect across the Laptev Sea continental slope

A schematic illustration of the water mass locations along the transects across the Laptev Sea continental slope is shown in Figure I.6.5.8.

The WSSWMLSS dominates at the surface layer of the western transect across the continental slope of the Laptev Sea (Figure I.6.5.8 top). Below the surface layer at the continental slope the Western Bottom Winter Water Masses of the Laptev Sea Shelf (WBWWMLSS) dominate at depths of 100 – 400 m (Figure I.6.5.8 top). The WBWWMLSS is characterized by low temperature, silicate concentration 6 – 7 μmol/kg, phosphate 0.7 – 0.8

71

μmol/kg, nitrate 6 – 7 μmol/kg, pH about 7.92, alkalinity about 2200 μmol/kg and oxygen about 320 μmol/kg (89 %).

Figure I.6.5.7: Nitrate (μmol/kg) (top), pH (center) and dissolved oxygen (μmol/kg) (bottom) distribution at the transect along the Laptev Sea continental slope.

In the bottom layer of this transect the Arctic Deep Water Mass is found. Here concentration of DO is from 310 to 320 μmol/kg (about 87 %), concentration of phosphate is about 0.9 μmol/kg, concentrations of silicate and nitrate are 7 – 9 μmol/kg and alkalinity >2300 μmol/kg, while pH is about 7.87.

The surface layer of the central transects (Figure I.6.5.8.center) has one type of water mass – the Arctic Surface Water Mass. On the Laptev Sea self (southern part of the transect) the Eastern Bottom Winter Water Mass of the Laptev Sea Shelf (EBWWMLSS) is found, which has high concentration of nutrients (> 12 μmol/kg of silicate, > 0.5 μmol/kg of phosphate and > 5 μmol/kg of nitrate), low oxygen concentration, pH values of about 7.81 and alkalinity > 2200 μmol/kg.

In the Atlantic Layer we found higher concentration of nutrients, lower oxygen and pH at the continental slope than in the AL in the deeper ocean (Figure I.6.5.8 center), suggesting that

72

perhaps EBWWMLSS properties propagate into deep layers along the continental slope. There are two types of water mass identified: the Eastern Deep Water Mass of the Laptev Sea and the Arctic Deep Water Mass in the deep part of the central transect.

Figure I.6.5.8: Schematic illustration of water masses along the transects across the Laptev Sea continental slope at western transect (100°E, top), central transect (126°E, center), and

eastern transect (142°E, bottom).

In the south part of the surface layer of the eastern transect across to the Laptev Sea continental slope (Figure I.6.5.8 bottom) the Western Surface Summer Water mass of the East Siberian Sea Shelf (WSSWMESSS) is observed. The WSSWMESSS is formed in summer with contributions from sea ice melting and wind mixing, and under the strong influence of the Laptev Sea Self surface water. This water mass is characterized by low nutrients concentration (about 0.05 μmol/kg of phosphate, less than 0.5 μmol/kg of nitrate and about 8.0 μmol/kg of silicate), alkalinity concentration about 2045 μmol/kg and pH limits from 7.87 to 7.90. In the central and northern parts of the eastern transect ESSWMLSS dominates. In the 200 – 800 m deep layer of this transect is the Atlantic Layer water mass. The bottom layer of the shallow area of the transect is most likely to be dominated by the Western Bottom Winter Water Mass of the East Siberian Sea Shelf (WBWWMESSS). Located deeper along the continental slope (Figure I.6.5.8 bottom) are the Eastern deep water mass of the Laptev Sea and the Arctic deep water mass.

73

I.6.5.3.5. Distribution of total dissolved inorganic carbon (DIC) and pCO2 The surface distribution of the total dissolved inorganic carbon (DIC) and pCO2 are shown in

Figure I.6.5.9.

Figure I.6.5.9: Surface distribution of total dissolved inorganic carbon (DIC) in μmol/kg (top) and pCO2 in μatm (bottom).

The range of DIC concentration in the surface water was from 1558 μmol/kg at station KD2205 to KD1881 μmol/kg at the station KD1605. The concentration of DIC was more variable in the eastern part of the study area than in the west. The observed DIC concentrations in the west varied from 1689 μmol/kg to 1799 μmol/kg. The maximum DIC concentration in the surface water was found in the central part of the investigated area.

The range of pCO2 in the surface water (10 m) ranged from 106 μatm to 213 μatm at stations KD0905 and KD2505, respectively. The minimum pCO2 was observed in the western parts of the investigated area. High surface pCO2 was found at the south shallow station of the central transect across the Laptev Sea continental slope and in the eastern area. The high value of pCO2 obtained in the eastern area (ESSWMLSS) points to a source of carbon dioxide to the atmosphere. The surface water pCO2 in the central part of the study area was quite constant at about 150 μatm.

The distributions of DIC and pCO2 with depth are shown in Figure I.6.5.10. The minimum DIC concentration was observed in the surface layer, but also the largest

difference in concentration was found here. The DIC concentrations in the 25 – 100 m layer increase with depth, within a range of 1797 μmol/kg to 2273 μmol/kg. Deeper than the pycnocline the DIC concentrations are stable within a range of 2083 – 2132 μmol/kg, increasing somewhat with depth (Figure I.6.5.10 left).

The pCO2 minima are also located at the surface and increase with depth. In the pycnocline and deep layers the pCO2 profiles reveal intermediate maxima and minima, a result of biochemical processes and interaction with the Laptev Sea shelf.

The concentration of DIC and pCO2 in the different water masses are shown in Table I.6.5.1.

74

Figure I.6.5.10: Depth profiles of total dissolved inorganic carbon in μmol/kg (left) and pCO2 in μAtm (right).

Table I.6.5.1: Values of total DIC in μmol/kg and pCO2 in μAtm in the different water masses.

WSS

WM

LSS

ASS

WM

ESSW

MLS

S

AL

AD

WM

EDW

MLS

WB

WW

MLS

S

EBW

WM

LSS

WSS

WM

ESSS

WB

WW

MES

SS

DIC 1730-1850

1800-2000

1660-1850 ~2150 ~2170 ~2180 - ~2130 ~1625 ~2150

pCO2 135-200

215-265

240-317

325-360

255-340 ~385 - ~380 ~280 ~315

In general, somewhat higher concentrations of DIC and higher pCO2 were found in the eastern part of the study area than in the west. The highest concentrations were found in the eastern part of the AL (2), (Figures I.6.5.6, and I.6.5.8) close to the Laptev Sea continental slope. The lowest concentration of DIC and lowest pCO2 were found in the summer water of the Laptev and East Siberian seas.

I.6.5.4. Preliminary conclusions New information about the hydrochemical regime of the Laptev Sea continental margin area

was obtained. The water column of the study area was divided into different water masses using the hydrological and chemical signatures. The range in concentrations of the chemical parameters of the selected water masses is shown in Table I.6.5.2.

Table I.6.5.2: Values of chemical parameters in the different water masses in the north part of the Laptev Sea in September 2005.

DO Phosph. Nitrate Silic. Alkal. Name Abbrev. μmol/kg % μmol/kg pH

Western surface

summer water mass of the

WSSWMLSS >375 >100 0.15-0.25 0.0-0.5 <5.0 1800-2050 >8.04

DIC

75

Laptev Sea Shelf

Arctic surface summer water

mass ASSWM ~370 ~99 ~0.20 ~0.5 <8.9 1960-2060 7.90-7.95

Eastern surface summer water

mass of the Laptev Sea

Shelf

ESSWMLSS 355-370 99-100 ~0.25 ~1.0 >8.9 1885-1905 7.87-7.91

Atlantic water mass AL 308-330 87-92 0.10-0.95 5.0-9.0 6.0-8.0 2200-2300 7.85-7.95

Arctic deep water mass ADWM 310-320 ~87 ~0.90 7.0-8.0 7.0-8.0 >2300 ~7.87

Eastern deep water mass of the Laptev Sea

EDWMLS ~305 <87 >1.00 >9.0 >8.0 >2300 <7.85

Western bottom winter water mass of the Laptev Sea

Self

WBWWMLSS ~320 ~89 0.70-0.80 6.0-7.0 6.0-7.0 ~2200 ~7.92

Eastern bottom winter water mass of the Laptev Sea

Self

EBWWMLSS low low >0.50 >5.0 >12.0 >2200 ~7.81

Western surface

summer water mass of the

East Siberian Sea Shelf

WSSWMESSS high high ~0.05 <0.5 ~8.0 ~2045 7.87-7.90

Western bottom winter water mass of

the East Siberian Sea

Self

WBWWMESSS low low >0.50 >4.5 ~7.0 2250-2270 ~7.89

Figure I.6.5.11: The profiles of oxygen (in μmol/kg, and %), silicate and phosphate (μmol/kg) at stations KD2005, September 16, 2005, 129,32 °E, 79,83 °N (blue line with rings); 122, August

8, 1998, 129,58 °E, 78,03 °N (green lines with rhombuses); and station 104, September 3, 1996, 132,54 °E, 78,29 °N (red lines with square).

The profiles of oxygen, phosphate and silicate as observed in 2005 are compared with data from 1996 and 1998 (Figure I.6.5.11). The stations used for the comparison are located around

76

130 °E and 78 to 79.8 °N. The oxygen profiles (Figure I.6.5.11 left) of the NABOS-05 cruise are similar to the data from the Polarstern cruises in 1996 and 1998. The NABOS-05 silicate data are higher than the data from 1996 and 1998 (Figure I.6.5.11), which might be explained by the different locations of the stations. A definitive answer would require some further studies. The phosphate profiles of 2005 and 1998 are similar, while the 1996 profile shows lower concentrations below ~200 m (Figure I.6.5.11 right).

Figure I.6.5.12: The ratio between salinity (psu) and alkalinity (μmol/kg) in the surface water (depth 10 m). Red lines give the salinity – alkalinity properties when Atlantic Layer water is

mixed with sea ice melt water or meteoric water, respectively [Yamamoto-Kawai et al., 2005]

The relationship of salinity to alkalinity in the surface water is shown in Figure I.6.5.12. Almost all salinity – alkalinity data from the eastern stations are located outside the limits between mixing of Atlantic water, sea ice melt water and meteoric water ratios. At stations KD0105 – KD1305, KD2105, KD2205, KD2705, and KD3705 sea ice melt has contributed to the surface water.

Acknowledgments: We gratefully acknowledge the financial and technical support by the NABOS project and by the Russian-German Otto Schmidt Laboratory for Marine and Polar Research, and the financial support by the Swedish Research Council and by the Royal Swedish Academy of Sciences.

I.6.6. BIOLOGICAL OBSERVATIONS (C. Bouchard and L. Fortier, LU)

I.6.6.1. Objectives Three main objectives have motivated Université Laval participation in NABOS missions

since 2003: 1) to study the Laptev Sea mesozooplankton community; 2) to identify factors that promote the growth and survival of juvenile arctic cod (Boreogadus saida); 3) to monitor vertical fluxes of particles and quantify different biological processes that drive those fluxes.

Each approach includes a comparison with other regions of the Canadian Arctic where similar sampling is presently conducted as part of the Cooperative Atmosphere Surface Exchange Study (CASES) and ArcticNet programs.

The comparison of the spatial distribution of the mesozooplankton community and its biomass variability across the shelf break of the Laptev Sea and between the Laptev and other Arctic shelf regions will help to answer questions such as: Are all the shelves and continental

The western stations KD0105 - 1305.

Stations KD2105, 2205, 2705, and 3705

77

slopes equal along the circum-Arctic? For years now, constant values were used to describe biological processes and to build large scale models using the assumption that communities are analogous throughout the Arctic. Those constants were often taken from various remote locations that sometimes have nothing in common. This can also be an interesting complement to the work done during previous studies of the Laptev Sea [Kosobokova et al., 1998; Abramova, 1999; Kosobokova and Hirche, 2001].

The Arctic cod is a key species in the Arctic marine food web because it channels most of the energy from secondary production to higher trophic levels (birds, seals and polar bears, Welch et al., 1992). The species is intimately adapted to life under and inside sea ice, at least during part of the juvenile and adult stage (e.g. Gradinger and Bluhm, 2004). Apart from the very first weeks of life, we know little about the life cycle elements of this important species, including reproductive activities and egg development in the natural environment. By comparing different habitats and ecosystems across the Arctic Ocean we aim to distinguish between local factors that can promote growth and survival, and general species adaptation to the cold Arctic environment. Study of genetic differentiation in different fish stocks across the Arctic holds potential for defining the structure of the whole arctic population.

Finally, the sequential sampling of the vertical flux using a sediment trap mooring will primarily compare the upper ocean biological processes to the deep ocean sinking particles. This study will also serve as a comparison with long-term sediment traps deployed on the same schedule within the ArticNet framework in the Beaufort Sea, the North Water and Hudson Bay.

I.6.6.2. Methods A conical net of 1 m diameter and 263 µm mesh, equipped with a TSK flowmeter towed from

500 m to the surface, or from the bottom at shallower stations, was used to sample mesozooplankton. In addition, a small net of 10 cm diameter with 50 µm mesh was attached to the main sampler, allowing the capture of small zooplankton, including copepod nauplii, the main staple of Arctic cod larvae and juveniles. This setup allows us to uniformly sample all the target species. The sampler was deployed at 36 out of 41 stations. Zooplankton samples were preserved in a 4% buffered formalin solution. Samples will be counted and organisms will be identified to the lowest taxonomic level possible in the near future at Université Laval.

A rectangular frame supporting two 1 m2 nets (mesh sizes of 500 µm and 750 µm respectively) and equipped with a flowmeter was towed from the ship’s side at 2 knots for 20 minutes (maximal depth of about 70 m) at each station where ice conditions allowed, i.e. 30 out of the 41 stations. Juvenile Arctic cod caught by the trawl were removed from the sample, individually measured, photographed and preserved in 95% ethanol. The remainder of the zooplankton sample was preserved in formalin. In the lab, fish otoliths will be removed and their microstructure will be analyzed to estimate survival and individual daily growth. Stomach contents will also be analyzed.

Particle fluxes are measured with two sediment traps installed on mooring line M3, which is also equipped with different instruments to take physico-chemical and current data (See Chadwell and Dempsey, section I.6.4.4.2, “Mooring design and equipment” of this report for complete details on mooring design and technical information). After recovery of the mooring line, sediment trap samples (12 cups per trap) from 2004 were recovered, the traps were reconditioned and then redeployed on the M3b mooring line. A technical problem (traced back to the factory design) with the Technicap PPS/3 trap’s electronic boards caused the failure of sample tray rotation in 2004. Therefore, while an estimate of the overall annual flux is available, the distribution over time of this flux remains unknown for 2004. The defective electronic boards were replaced during NABOS-05 and the programmed time sequence for both traps is presented in Table 1. Microscopic observations and chemical analysis will be performed on future samples after retrieval in 2006. Biogenic elements (Particulate Organic Carbon [POC], Particulate Organic Nitrogen [PON], BioSi, carbonates), planktonic organisms (swimmers, algae cells), and derivate materials (marine snow and fecal pellets) will be analyzed in our Québec laboratory while the National Institute of Polar Research (NIPR) in Japan will analyze the biological and lithographic particles (C13, C15, Pb210) in order to assess their origin.

78

Table I.6.6.1: Technicap PPS/3 opening/closing sequence at the NABOS-05 M3b mooring

Sample cup #. Open Close Collection

days

1 17 Sept.,

2005 30 Sept., 2005 14 2 1 Oct., 2005 31 Oct., 2005 31 3 1 Nov., 2005 31 Dec., 2005 61 4 1 Jan., 2006 31 Mar., 2006 90 5 1 Apr., 2006 15 May, 2006 45 6 16 May, 2006 31 May, 2006 16 7 1 Jun., 2006 15 Jun., 2006 15 8 16 Jun., 2006 30 Jun., 2006 15 9 1 Jul., 2006 15 Jul., 2006 15

10 16 Jul., 2006 31 Jul., 2006 16 11 1 Aug., 2006 31 Aug., 2006 31 12 1 Sept., 2006 15 Sept., 2006 15

Total (days) 364

I.6.6.3. Preliminary results

Zooplankton sampled from the Laptev Sea by Université Laval since 2003 have not been analyzed yet for want of human and financial resources. Hopefully, some results will become available in the near future. Table I.6.6.2: List of stations sampled with the horizontal net, number of juvenile fish collected, and mean length of arctic cod.

# of Mean

Length # of Average salinity Station STATION Arctic

Cod (mm) other fishes 0 to 60 m

depth (m)

KD0105 0 . 0 33.20 1500 KD0305 0 . 0 33.25 2500 KD0405 0 . 0 33.25 2200 KD0905 1 21.0 2 33.48 110 KD1105 0 . 0 32.62 1500 KD1205 0 . 0 32.45 1500 KD1305 0 . 0 32.24 1500 KD1405 20 42.7 0 32.10 1500 KD1505 10 44.7 1 31.70 1500 KD1705 6 36.5 0 31.78 3000 KD1905 14 37.0 0 31.49 3000 KD2105 17 35.5 1 31.45 3000 KD2205 14 31.9 0 30.69 2800 KD2305 18 32.2 0 30.56 1600 KD2405 50 31.7 0 30.50 1600 KD2505 5 29.6 1 30.07 1600 KD2605 11 33.7 1 29.79 1320 KD2705 3 30.0 2 30.99 1170 KD2805 11 31.8 0 31.31 500 KD2905 5 37.6 0 31.24 218 KD3005 29 37.0 0 31.01 98

79

KD3105 11 30.4 0 30.57 1500 KD3205 6 30.2 0 31.61 1500 KD3305 66 36.1 0 31.49 1500 KD3605 10 34.0 0 31.85 2400 KD3705 10 36.8 0 31.88 1700 KD3805 33 37.6 0 32.21 1800 KD3905 55 38.4 0 32.14 1420 KD4005 13 44.3 0 32.52 112 KD4105 9 40.7 0 32.00 67

Total 427 8

A total of 427 juvenile arctic cod have been caught at 24 of the 30 stations where the horizontal net has been deployed, along with 8 juvenile fishes belonging to other species (see Table I.6.6.2). There is no evident spatial pattern in number but juvenile arctic cod caught in the south part of line B (Figure I.6.4.3, stations KD3605 to KD4105 and KD1405-KD1505) have the higher mean standard length. On transect C, fishes from stations KD2905 and KD3005, located in the south part, were on average longer than those captured in the north part of this same transect. There was no effect of the temperature of the first 60 m on numbers of juvenile arctic cod caught, or mean length, nor any relation between those variables and station depth.

Arctic cod standard lengths varied from 14 to 59 mm with a mean of 36.1 mm (n = 427), in comparison with standard length between 17 and 55 mm with a mean of 26.4 mm in 2003 (n = 170, see Figure I.6.6.1). Since above zero sea-surface temperature and low ice concentration promote feeding success and survival, we think that the 2005 cohort has experienced better conditions (2005 is the year of record low arctic sea ice extent and high air temperature) than 2003’s, and that a stronger recruitment in 2005 can partly explain the higher number of juveniles caught that year. Aging of 2003 and a part of 2005 juveniles by otolith analysis has been done and preliminary results suggest that growth rate doesn’t differ between those two years. A better survival of the larvae hatched early in spring may explain the difference in the length distribution of the fishes in 2003 and 2005. Fortier et al. [2006] shows that, in the Northeast Water (Greenland Sea), early hatched Arctic cod larvae generally experience massive mortality but may show an exceptionally high survival rate during some particularly warm years, grow bigger than larvae hatched during summer and supplant them by the end of the season. Otolith analysis shows that the bigger 2005 juveniles are older than those of 2003, a result that supports Fortier et al.’s [2006] hypothesis. Therefore, indications are that Arctic cod were affected (positively) by the exceptional ice conditions in 2005.

0

5

10

15

20

25

30

35

40

45

14-19 19-24 24-29 29-34 34-39 39-44 44-49 49-54 54-60

Standard length (mm)

Pour

cent

age

of to

tal c

atch

20032005

Figure I.6.6.1: Size distribution of juvenile arctic cod (Boreogadus saida) captured during NABOS 2003 and 2005

80

I.6.7. THE USE OF NATURALLY OCCURRING TH-234 AS A PROXY FOR POC FLUX IN THE ARCTIC OCEAN (K.Cochran, NYU, and J.Deming, UW)

This project has as its goal the use of the naturally occurring radionuclide Th-234 (half-life =

24 d) to determine POC export from the upper water column (0-200 m). Th-234 is produced from decay of dissolved U-238 and is scavenged onto sinking paryocles. Because the rate of production is known (from the U-238 activity of seawater), measurement of the Th-234 remaining in the water column provides a means of calculating (via a mass balance) the export flux of Th-234 through any given depth. The Th-234 flux may be converted into a POC flux if the POC/Th ratio on the settling particles is known. During the NABOS-05 cruise, we collected small volume (2-4 l) water samples for measurement of total Th-234 and deployed in situ pumps at 25 and 100 m for collection of filterable particles. The pumps collected particles in size ranges >70 µm and 1-70 µm, with the former assumed to comprise the settling fraction. Samples were collected at the stations referred to in Table I.6.7.1:

Table I.6.7.1: NABOS-05 sampling for Th-234

Station Sampling

Date Latitude Longitude Rosette Sampling Depths Pump Sampling

Depths (N) (E) (m) (m)

KD0105 9/11/2005 81° 38.0' 97° 25.0' 500 KD0805 9/12/2005 8° 34.0' 102° 3.98' 10, 25, 50, 75, 100, 150 25, 100 KD1905 9/16/2005 79° 48.84' 126° 12.52' 10, 25, 50, 75, 100, 150 KD2305 9/17/2005 80° 24.60' 140° 19.69' 10, 25, 50, 75, 100, 150 25, 110 KD2605 9/18/2005 79° 55.10' 142° 21.15' 10, 25, 50, 75, 100, 150 KD3705 9/21/2005 77° 46.42' 125° 56.79' 10, 25, 50, 75, 100, 150 KD4005 9/21/2005 77° 6.99' 126° 14.02' 10, 25, 40, 50, 60, 80 25, 61

The samples were processed on board and returned to the laboratory for measurement of

Th-234. This project is collaborative with Dr. Jody Deming (University of Washington). The purpose of the collaborative research is to investigate what bacteria are present and determine the rates of enzymatic activity on filterable particles sampled with the in situ pumps. One PhD student, Sharon Hoffman (Woods Hole Oceanographic Institution) and one post-doctoral fellow, Alexandra Thompson (Univ. of California-Berkeley) assisted with the work.

I.6.8. ABUNDANCE OF HETEROTROPHIC BACTERIA AND NANOFLAGELLATES

IN THE LAPTEV SEA (K.Iverson, UT) Background: In the search to understand marine carbon transfer, a better understanding of

different organic carbon compartments is needed. The microbial loop is one such compartment, forming an alternative, important food web that was discovered only a few decades ago. The basis of the loop is marine bacteria, which take up organic compounds released to the water masses by microalgae and zooplankton. Bacteria are then preyed upon by small, motile algae called nanoflagellates, which in turn are eaten by small zooplankton called ciliates. Eventually the ciliates are prey for bigger zooplankton, constituting a link back to the classic food chain. Several of the microbial organisms, like the nanoflagellates, challenge adequate carbon budgets by both producing and/or consuming carbon due to different nutrition modes. The microbial loop reduces vertical carbon export, enhances remineralization and increases production in the surface layer. Few investigations of spatial and temporal distribution of the members of the microbial loop have been conducted in Arctic waters. During the NABOS cruise to the Laptev Sea in September 2005, basic data on chlorophyll a (chl a), POC, abundance of heterotrophic bacteria and abundance and relative distribution of trophic modes in nanoflagellates were collected.

Objectives: 1: to estimate the abundance of heterotrophic bacteria and different size fractions in the

nanoflagellate community in the Laptev Sea;

81

2: to estimate the relative distribution of autotrophic and heterotrophic nanoflagellates in the Laptev Sea; and

3: to compare the dynamics of the bacterial and nanoflagellate communities at near and far distance from the Lena River output and over the shelf-edge.

Activities: Water for different analyses was collected with the CTD water rosette from several depths

(10 m, 20 m, 30 m, 40 m, 50 m, 75 m and 100 m) along two main transects over the shelf; one near the river discharge (St. KD4105, 1605, 3505, and 1905) and one further east (St. KD2305, 2405, and 2905).

Methods: Whole water samples were filtrated and the filters frozen for analysis of chl a and

POC. Water was fixed and frozen in liquid nitrogen to analyze bacterial abundance using flow cytometry. DAPI stains were made of the nanoflagellate community, to be counted under an epifluorescence microscope.

I.7. IARC SUMMER SCHOOL ABOARD KAPITAN DRANITSYN (V.Alexeev, IARC)

In 2005, the annual NABOS expedition was conducted in parallel with a summer school on board the icebreaker Kapitan Dranitsyn. This was the third IARC-supported summer school. Two previous summer schools were held in Fairbanks. A total of 24 university students and early career scientists were chosen, out of about 140 summer school applicants: seven from the United States, five from Russia, five from Canada, two from Norway, and one each from Belgium, Denmark, France, Germany, and Sweden. Vladimir Alexeev of IARC, and the author of this meeting report, served as the director of the school; Louis Fortier of Laval University (Quebec City, Canada) was co-director.

Thirteen instructors taught during the summer school, and most were also involved in the field program. Lectures on board covered a wide variety of subjects, from simple climate models to microbiology, astrobiology and marine isotope analysis. Overview lectures by Roger Barry (National Snow and Ice Data Center, Boulder, Colo.) and Genrikh Alekseev (Arctic and Antarctic Research Institute, St. Petersburg, Russia) on the history of Arctic exploration were well attended and inspired many questions. General discussions on various problems concerning Arctic science and performing research in the Arctic were also a large part of life on board.

The International Polar Year (IPY) theme was one of the most exciting topics during these informal meetings. The general feeling among the participants was that a more active role by U.S. funding agencies in IPY is desirable.

In addition to attending traditional lectures and seminars, the students aboard the icebreaker had a unique chance to experience Arctic exploration and acquire valuable skills in oceanographic fieldwork under harsh conditions. Students learned first-hand about oceanographic, biochemical, ice, and meteorological observations in this dynamically and important area of the Arctic. Working with the international team of experienced polar researchers provided them with an excellent opportunity to learn more about modern methods of high-latitude observations and analyses, and to personally participate in the study of a fast changing environment.

All of the students were assigned to projects. Some projects were related to the field measurements program, and other themes were offered by the instructors. The students spent long hours in the lounge completing the projects and interacting with the instructors, and the final presentations proved a great success. Some of the students may even have collected enough data to publish an article. The project reports are being compiled for the summer school’s final expedition report. The books of abstracts, for both the lectures and the students’ projects, are available online at http://www.iarc.uaf.edu

The atmosphere on the boat was friendly and cooperative. We experienced no difficulty communicating with the crew, because there were enough people able and willing to translate Russian to English. The crew did its best to accommodate the needs of the summer school and the expedition. The friendly service of the Murmansk Shipping Company, represented by Nikolay Rumyantsev, provided all that was needed to make the cruise a success.

82

Not only did students learn about the fundamentals of Arctic research while enjoying good Russian cuisine (especially everyone’s ‘favorite’ beef tongue!), they also experienced the culture of life aboard a research vessel. Close quarters, sea sickness, and the endlessness of the open ocean were new to some. The boat stayed on Moscow time during the cruise, and therefore when we floated in the Laptev Sea (which is about five to six hours ahead of Moscow time) it was dark by 5:00 P.M., and the sun rose around 11:00 P.M. With these hours of daylight, students often performed ‘all-nighters’ on experiment work shifts or completing projects.

Moreover, the summer school students were able to interact—and foster international cooperation and collaboration—not only through science, but also through the shared experiences of life in the field. A big joke on the cruise was the Arctic Cod Trophy fishing contest, conducted by Louis Fortier’s group as a part of the group’s research of ecosystems in the Arctic. The winners, Danny Dumont and Romain Langlois, reeled in a ‘giant’ 6.9-centimeter trophy fish.

Students also experienced the hindrances to collecting data in extreme environments. One long-term IARC mooring, deployed in September 2002 and scheduled for collection by the expedition, had become completely buried under a vast multiyear ice floe. This mooring contained long-term data of temperature, salinity and ocean currents, which were later used for several students’ projects. All activity stopped for 14 hours and everyone was called to the bridge to look for the buoys connected to the mooring. The icebreaker had to crush many ice floes before the mooring popped to the surface. The mooring was recovered despite the darkness, and the measurements program continued.

The summer school helped instructors and students establish professional and personal contacts. Perhaps of even greater importance, all of those aboard the Kapitan Dranitsyn during the three weeks at sea together became good friends. For 2006, there are plans to organize a summer school for international K-12 teachers onboard the icebreaker.

The summer school was supported by NSF (through IARC), NOAA, ArcticNet, the Network for Centers of Excellence (Canada), the Russian Foundation for Basic Research, the Ministry of Science, and the Japan Agency for Marine-Earth Science and Technology (JAMSTEC).

The main organizers included IARC (University of Alaska Fairbanks, United States), Laval University (Canada), the Institute for Atmospheric Physics (Moscow, Russia), and the Arctic and Antarctic Research Institute (St. Petersburg, Russia).

83

SECTION II

Expedition to the western Nansen Basin aboard

R/V Lance in September 2005

Vladimir Ivanov1, Jurgen Holfort2, and Edmond Hansen2

1 - International Arctic Research Center University of Alaska Fairbanks

Fairbanks, Alaska, USA

2 – Norwegian Polar Institute Tromsø, Norway

84

II.1. INTRODUCTION

The September 2005 cruise on R/V Lance was conducted by the NPI (chief scientist Jurgen Holfort) in the framework of the Arctic/Subarctic Ocean Fluxes (ASOF) project. The main purpose was to maintain the NPI mooring array in the western Fram Strait and to acquire CTD data at standard monitoring lines. The NABOS-related task was to recover and to redeploy the long-term mooring M4 on the continental slope between Svalbard and Franz Joseph Land and to carry out CTD observations around the site of deployment. II.2. RESEARCH VESSEL

R/V Lance (Figure II.2.1) is the research facility of the Norwegian state scientific agency routinely employed by the NPI for carrying out oceanographic studies in the Nordic Seas and an adjacent part of the Arctic Basin. Her main technical characteristics are presented in Table II.2.1.The ship can navigate through the pack ice with concentration up to 70%. There are three research laboratories in the front part of the ship and enough space for placement of additional container-laboratory on the working deck. Routine oceanographic equipment includes a CTD-profiler mounted on a 12-bottle rosette. The rosette is deployed using an hydraulic winch with a 9-mm cable wire. On-deck handling of the rosette is facilitated by the A-frame. Another winch in conjunction with a 10-ton crane is used for mooring deployment and recovery. Both winches are located on the working deck in the front part of the ship. There is a helicopter deck in the rear part of the ship (a helicopter was not employed during this cruise). Table II.2.1: Main technical characteristics of R/V Lance. Gross tonnage 1334 GRT Max draft 6.5 m Breadth 12.6 m Length 60.80 m Freeboard to working deck 3 m Cruising speed 10.5 knots Range 21000 nm Endurance 85 days Ice breaking ability Yes, DnV ICE 1A certificate Max crew and scientists 13 and 25

Figure II.2.1: R/V Lance, general view.

85

II.3. CRUISE OUTLINE The cruise started from Longyearbyen, Spitsbergen on August 28, 2005. The program

activities commenced on August 29 with the CTD section across the continental slope in western Fram Strait (Figure II.3.1). Within the following 10 days three moorings were recovered/redeployed in western Fram Strait. Four moorings were not found. Fifty CTD stations were taken along the mooring line. Ice thickness measurements were carried out at 12 ice stations. On September 8 Lance made a brief call to Ny-Alesund, Spitsbergen, where two members of the scientific crew disembarked. On September 10 Lance approached the site of the NABOS mooring, but became stuck in the heavy ice about 15 miles away. Unable to move forward, Lance started maneuvering through the openings in the ice cover and by the end of the day she was as far as 47 miles to the southeast. The weather grew worse. Northwest wind was strengthening. From the available satellite images it was clear that the area of the mooring was completely covered by ice of 100 per cent concentration. To the west of the mooring position there was a tongue-shaped opening in the ice cover, which extended to the north-northeast inside the ice field. The width of this opening was about 20-30 miles. Lance moved to the west along the ice edge, then turned to the north and tried to get into this flaw, which was predicted to shift to the east driven by favorable wind. In the morning of September 11 it appeared that Lance was still about 38 miles away from the mooring position. The wind was stormy (22.5 m/s on the average), visibility was obstructed by occasional snow outbreaks to 200-300 meters, and by noon the ship was again stuck in the ice. Lance moved in a southeast direction, finding pathways between huge ice fields (up to 1 kilometer in width). By the end of the day, after a series of unsuccessful maneuvers it became clear that the ship was not approaching the mooring at all. With time running out, the probability of reaching the mooring was even less than the day before. Therefore, in the evening of September 11 it was decided to cease additional tries and to turn to the south. During the following 3 days a series of 5 CTD sections was taken, including 67 stations between the eastern isles of Svalbard Archipelago. On September 14 Lance started steaming to TromsØ. A day before arrival in TromsØ three acoustic moorings were recovered. These moorings were deployed in the eastern Norwegian Sea in July 2005 for communication with submarine gliders. The cruise terminated in TromsØ, Norway on September 17, 2005. The complete cruise log is presented in Appendix 3.

Figure II.3.1: R/V Lance cruise track.

86

II.4. SCIENTIFIC PARTY • Jürgen Holfort, NPI • Kristen Fossan, NPI • Harvey Goodwin, NPI (left in Ny-Alesund) • Angelica Renner, NPI (left in Ny-Alesund) • Vladmir Ivanov, IARC • Alexander Smirnov, AARI

II.5. WEATHER AND ICE CONDITIONS

Weather conditions over the study area during the period of the cruise were very variable. We experienced rapidly changing winds, up to 25 m/s, mostly cloudy conditions, air temperature around zero centigrade and occasional snow outbreaks. The wave/swell height in the open water was 2-3 meters on the average and did not seriously impede outboard operations.

In Fram Strait the drifting ice was observed to the west of 3°W. Maximal ice concentration was 100%. The average ice thickness was 3-4 meters (according to the direct measurements from the ice floes). Hard ice conditions essentially obstructed mooring operations; at best, substantial extra time would have been required to carry out mooring recovery/deployment, and at worse, the task was completely impossible. The area around the M4 position was blocked by huge ice fields, creating an insuperable obstacle for the ship (Figure II.5.1).

Figure II.5.1: Ice conditions on September 10-14/2005. Location of M4 is shown by

red circle (http://www.aari.nw.ru/index_en.html).

II.6. CTD OBSERVATIONS II.6.1. Background information

CTD measurements were carried out in the areas where ice conditions allowed the ship to navigate. Since the cross-slope section covering the position of M4 appeared to be inaccessible, observations were focused on the region to the south of the mooring site (Figure

87

II.6.1.1). Our choice of CTD section configuration was motivated by our intention to map the propagation of AW through the passages of the northwestern Barents Sea, a process which has not been clearly elucidated. According to historical studies by Mosby [1938] and Novitsky [1961] AW transport through the strait between Kvitoya and Nordaustlandet is directed to the south. On the other hand, year-long current measurements accomplished more recently in this strait showed mean northeast flow in the core of AW at 255 m [Aagaard et al., 1983]. Pfirman et al. [1994] suggested that a small portion of AW enters the Barents Sea between Kvitoya and Victoria Island, while the main southward transport occurs through Franz Victoria Trough. This conclusion was supported by oceanographic measurements in this area in 1998 [Ivanov and Korablev, 2004]. The south branch of AW entering the Barents Sea with the North Cape Current predominantly moves eastwards towards Novaya Zemlya, and then turns to the north (e.g. Ozhigin et al. [2000]). However, there is some observational evidence indicating penetration of the AW from the south to the northwestern Barents Sea [Pfirman et al., 1994; Loyning, 2001]. Detailed information on the AW spreading and transformation in the northwestern Barents Sea is important for achieving a better understanding of the outflow properties through St. AnnaTrough, which contribute to the hydrographic structure of the Nansen Basin.

II.6.2. Methods

The spatial resolution of CTD stations was 5-10 miles (Figure II.6.2.1). Six sections containing 63 stations were completed in 3 days. The casts were run from about 1-2 m below the surface to 7-10 m above the bottom. The speed of descent was close to 1 m/s. Approach to the seabed was indicated by a bottom-alarm device. Temperature and conductivity sensors operated steadily.

SBE SEASOFT software for Windows was used for data acquisition and processing. Derived variables include pressure (in db), water temperature (in °C), and conductivity (S/m). The processed data (depth, temperature and salinity) with 1 m vertical resolution were added to the IARC database.

Figure II.6.2.1: Location of CTD stations in the western Barents Sea. Black cross denotes the position of the M4 mooring.

88

II.6.2.1. Equipment

CTD profiles were recorded using a Seabird profiler SBE911plus. This system continuously measures conductivity, temperature and pressure at 0.25 m intervals in the vertical. Technical specifications for the device are available at the web-site http://www.seabird.com/products/spec_sheets/911data.htm. The water sampling was carried using General Oceanic Rosette Model SBE 32 with five five-liter Niskin bottles. II.6.2.2. Preliminary Results

According to the previous surveys in the northwestern Barents Sea (see references in section II.6.1), AW may enter the study area from the north (North AW, NAW), and from the south (South AW, SAW). Despite having originated from the same source (Norwegian Atlantic Current), these two water masses have different properties due to different histories after splitting into two branches. In general, NAW is fresher than SAW since its transformation is more affected by melting ice. In order to distinguish these two branches of the AW let us first consider a temperature-salinity (T-S) diagram containing a complete set of CTD data obtained in the western Barents Sea during this cruise (Figure II.6.2.2). The threshold salinity of Atlantic-derived water in the northwestern Barents Sea is 34.75 [Pfirman et al., 1994]. Hence only the data with salinity exceeding this value are shown in Figure II.6.2.2. Two clusters of points are clearly visible on the T-S diagram. The first one contains points with temperature over 2ºC and salinity below 34.85 PSU. Water with these properties fills the northern part of the area, including sections 1-4 and part of section 5. The second cluster contains colder (temperature around 1.5ºC), and saltier (more than 34.90 PSU) water. The water with these properties occupies section 6 and is also found in section 5. Therefore, taking into account typical properties of NAW and SAW known from literature (e.g. Pfirman et al., 1994), we may roughly draw the division line between these two water masses in the middle of section 5.

Figure II.6.2.2: Temperature-salinity diagram of all CTD data with salinity

exceeding 34.75.

Figure II.6.2.3: Temperature-salinity diagram of CTD data inside the NAW core

at sections 1-3

To depict a more detailed picture of AW spreading in the northwestern Barents Sea let us analyze vertical distributions of temperature, salinity and potential density. Vertical sections of hydrographic properties at 3 triangle-shaped northern sections (see Figure II.6.2.1) are presented in Figure II.6.2.6. Two isolated warm and salty cores are distinguished at the westernmost section 1, and at stations 73, 74 and 69, 70. These cores are embedded between 150 and 200 m. Maximum temperature (2.31ºC) is observed at station 74 at 174 m. Maximum

89

temperature at station 70 is about 1º lower (1.35ºC). These cores are also distinguished by local salinity maxima, 34.83 and 34.78 PSU respectively. Observed configuration of isotherms resembles the loop structure of the AW flow entering from the north (NAW), with an inflowing (warmer) branch at the western flank of the channel. Similar patterns are known in Franz Victoria and St. Anna troughs [Aagaard and Hanzlik, 1981; Schauer et al., 2002; Ivanov, 2002]. At zonal section 3 an isolated warm core (1.65ºC, 34.80 PSU), slightly shifted to the west, resides at the seabed. The triangle is closed to the eastern section, where the warmest water (1.05ºC, 34.74 PSU) is also located near the seabed at station 65. The T-S diagram for the stations containing the core of the NAW is presented in Figure II.6.2.4. As follows from this plot, cooling and freshening in the core is almost density compensated. An isolated patch of light blue dots with increased temperature and salinity at stations 69, 70 probably shows the lower part of the NAW inflow, which is below the sill depth at section 3.

Figure II.6.2.4: Temperature-salinity

diagram of CTD data inside the NAW core at section 4.

Figure II.6.2.5: Temperature-salinity diagram of CTD data inside the NAW and SAW cores

at sections 5 and 6

At longitudinal sections 4 and 5 (Figure II.6.2.7) a similar “inflow-outflow” pattern of the AW is observed. The inflowing AW between Kvitoya and Kong Karls Land is the warmest around this area. Maximum temperature (2.48ºC) was measured at station 91 at 222 m. The ‘outflow’ water with the core at station 94 is 0.26ºC colder and 0.07 PSU fresher (Figure II.6.2.4). At section 5 between Kong Karls Land and Storbanken, the AW core temperature in the ‘inflow’ and ‘outflow’ waters is almost the same, 2.05ºC. However, the salinity difference is huge: in the ‘outflow’ water salinity is 0.15 PSU higher than in the ‘inflow’ water. This means that the ‘outflow’ contains the water from a source different from the source of the ‘inflow’ (otherwise, temperature and salinity variation would be consistent, as is the case in the northern sections). According to Pfirman et al. [1994] the sill between Storbanken and Hopen Island does not completely prevent northward penetration of the SAW from the south. Therefore, we may guess that saltier ‘outflow’ water observed at section 5 contains some amount of SAW. To check this let us examine the T-S diagram calculated using the data taken inside AW cores at section 5, and the data from two of the easternmost stations (109 and 108) at section 6. The motive for choosing these two stations for comparison is explained by the local bottom topography: for dynamical reasons SAW overflow, if it is happening, has to be shifted towards the eastern slope of Storbanken. Three distinct water masses are distinguished in theT-S diagram, shown in Figure II.6.2.5: NAW (2.05ºC, 34.83 PSU), SAW (1.50ºC, 35.01 PSU) and the water mass with parameters lying in between: 2.05ºC, 34.99 PSU. SAW is denser than NAW. Therefore, after moving over the sill, SAW descends along the northern slope of Storbanken, submerging the NAW. This conclusion is supported by the distribution of salinity and potential density at sections 5 (Figure II.6.2.7) and 6 (Figure II.6.2.8).

90

Figure II.6.2.6: Vertical distribution of properties at sections1-3: temperature (ºC, top), salinity (psu, center), and potential density (bottom).

91

Figure II.6.2.7: Vertical distribution of properties at sections 4 and 5: temperature (ºC, top), salinity (psu, center), and potential density (bottom).

The nature of the warm and salty water mass discovered at section 5 is not clear. The high salinity of this water points to its origin in the south branch of AW. Since its thickness is very small (about 15 m) compared to the NAW (70 m at station 101) it may be an isolated lens of SAW, which traveled a long distance from the south gradually losing heat and salt. However, the present data are not sufficient to substantiate or reject this hypothesis.

92

Figure II.6.2.8: Vertical distribution of properties at section 6: temperature (ºC, top), salinity (psu, center), and potential density (bottom).

93

Based on this analysis we suggest the following scheme of AW spreading in the northwestern Barents Sea (Figure II.6.2.9), which supplements the existing scenarios (see Pfirman et al. [1994], their Figure 11).

Figure II.6.2.9: Scheme of AW spreading in the northwestern Barents Sea: NAW (red), SAW (blue). Solid lines are based on the data obtained on this cruise. Dashed lines are based

on other sources.

II.6.3. RECOMMENDATIONS FOR FURTHER MOORING OBSERVATIONS

Despite the Lance’s exceptional capability for navigation in ice-covered seas and the excellent skills of her crew, heavy ice conditions made it impossible to reach the M4 site in September 2005. Hence, the key question is: Could Lance have reached the M4 mooring site if she was given more time (how much?), or was this mission impossible under the ice conditions we faced?

There is no exact answer on this question; however, a basic assessment can be done. Satellite images of the ice concentration a week before and a week after our scheduled visit to the M4 site are presented in Figure II.6.3.1. At the beginning of September the mooring site was within the zone of 100% ice concentration, but during September 18-21 the mooring position was apparently within the marginal ice zone. The spatial resolution of the images is 12.5 km; therefore we cannot be certain whether the mooring was in fact in the light ice area, or in the zone with high ice concentration.

The entire Lance cruise lasted 21 days. During this period, the position of M4 was constantly covered with heavy ice. The situation started to improve only after September 20, i.e. after the cruise was finished. Thus, extra time within the given time window was still not enough to do the

94

job. Taking into account that, on average, the first half of September is the season when Arctic ice cover reaches its annual minimum, the basic recommendation coming out of this analysis is the necessity of backing up mooring operations carried out onboard Lance. This backup may be provided by I/B Kapitan Dranitsyn. The task to recover/redeploy M4 should be included in Kapitan Dranitsyn’s next year’s cruise plan as a possible option if conditions prevent the task from being accomplished by Lance.

Figure II.6.3.1. Ice conditions on September 4-7/09/2005 (top) and 18-21/09/2005 (bottom). Location of M4 is shown by red circle (http://www.aari.nw.ru/index_en.html).

95

SECTION III

Cruise Report of the CABOS-05 Expedition to the Beaufort Sea aboard Canadian Coast Guard

Icebreaker Louis S. St-Laurent , September 2004

Sarah Zimmerman1, Eddy Carmack1, and Igor Polyakov2

1 – Institute of Ocean Sciences, Sidney British Columbia, Canada

2 - International Arctic Research Center

University of Alaska Fairbanks Fairbanks, Alaska, USA

96

III.1. INTRODUCTORY NOTE

Pursuing the goals of our long-term monitoring program, we continued our CABOS mooring-based observations in the Canadian Basin of the Arctic Ocean in 2004-05 (Figure III.1). Our objective is to measure the internal temperature, salinity, and density structure of the basin and how these parameters change over time, as well as measuring inflows and outflows from the basin, allowing the integrated heat and fresh-water budgets of the Canadian Basin to be studied. This record added one more year of observations to the existing several years of measurements from the same location in the Canadian Basin. Note however that limited funding did not allow us to expand the CABOS program as planned, and our hope is that the forthcoming IPY (2007–09) will help us leverage the necessary funding for the growing large-scale mooring-based observational program.

Figure III.1: Map showing locations of the moorings deployed in 2001, 2002-05.

III.2. RESEARCH VESSEL AND CRUISE PLAN

A brief description of the ship CCGS Louis S. St.-Laurent used for mooring deployment and recovery can be found below in Table III.1, copied from the Canadian Department of Fisheries and Oceans web-site: 7http://www.ccg-gcc.gc.ca/vessels-navires/details_e.asp?id=A-1.

97

Table III.1: Canadian Coast Guard CCGS LOUIS S. ST-LAURENT

Official No: 328095 Type: Heavy Gulf Icebreaker Port of

Registry: Ottawa

Region: Maritimes Home Port: Dartmouth, Nova Scotia, Canada

Call Sign: CGBN 8H

When Built: 1969 Builder: Canadian Vickers, Montreal, Québec, Canada

Modernized: 1988 - 1993 - Halifax Shipyard & 2000 new props Certificates Complement Class of Voyage: Home

Trade I Officers: 13

Ice Class: 100 A Crew: 33 MARPOL: Yes Total: 46 IMO: 6705937 Crewing Regime: Lay Day Available Berths: 53

The program for the extended cruise of the Canadian icebreaker in 2005 included several

mooring deployments and recoveries for several scientific programs and CTD surveys including CABOS mooring recovery and deployment (see Figure III.1 for mooring location). The process of CABOS mooring recovery is captured in Figure III.2.

Figure III.2: Recovery of CABOS mooring from the Canadian Coast Guard Icebreaker Louis S. St-Laurent.

98

III.3. MOORING RECOVERY AND DEPLOYMENT Dr. Sarah Zimmerman, leader of the IOS expedition aboard the Canadian icebreaker, wrote

from the sea: “We arrived on site at midnight local time. While waiting for mooring operations to start in the morning, we performed a profile rosette cast, two net casts down to 100m and two bottle flushing study casts, where we also collected water at 1000m for the CFC analyzers.

“During the night and morning we had a constant drift of S to SE of 0.3knt, and very light wind (3-4 knots). The water was mostly open although we did have blocks/100m pans of multiyear ice (~1/10?). The night temperatures had been below freezing and the deck was icy to start with in the morning. Before recovery in the morning a fog came down, but lifted just before operations began.

“At 7 am we were on site and ranged on the mooring. The ranging was performed using the Woods Hole Oceanographic Institution’s (WHOI’s) deck box in the container on the foredeck. They now have GPS with their transducer as well as a 12 kHz bottom sounder in this lab. Having their own GPS alleviates the mismatch in distances (trying to match the horizontal range given by the transducer and the range on the bridge to the mooring position because the transducer and GPS antenna are ~10m apart), and keeps it simple by not having to relay positions noted by the bridge to the lab during the ranging. The mooring range difference between the lab and bridge was ~20m.

“At 8am we started the mooring recovery operation. The crew was instructed in how to use the WHOI Lebus winch, and the blocks, lines and water hoses were assembled. The block holding the hydro/bongo wire was taken off because the wire termination is too large to slide through the block.

“The mooring was ranged on just before recovery: 46m from lab, 70m from bridge, bridge position 71°46.476N, 131°52.571W with the mooring site directly off the bow. We backed off slightly from the site to make sure we were not over it and took a new range: 130 from lab, 166m from bridge, bridge position 71°46.510N, 131°52.711W. The area around the mooring was ice free. The release command was given at 14:38 UTC (8:38 local). The mooring did not surface although the release gave confirmation that it had opened. The water was open enough not to suspect the mooring had come up under anything. After five minutes or so, Doug went back into the lab to open the second release. At 14:43 Doug had confirmation that the release had opened. At 14:46 the mooring was at the surface, perfectly positioned about 100m forward of the starboard bow.

“Release comments: The release was not fully vertical in the water column, perhaps due to insufficient buoyancy? The release may not have opened properly because of its angle/position. The second release gave an open confirmation and the mooring was on the surface within 3 minutes. Once on deck, the first release let go of the chain; it had been open but it took a jostle to free the chain. We had a similar problem last year, and we blamed the bar that joined the two releases which was then replaced with a chain from WHOI. Perhaps buoyancy was a problem in 2004 recovery as well and not the bar?

“There was no unusual growth or corrosion on the release assembly and the MMP cable was quite clean and in good condition. Captain Potts was at the wheel for the recovery. He pulled the ship close to the mooring, and the bosun, Bob Taylor, was able to catch the top ring of the float with a hook from the crane.”

III.4. CABOS MOORING DESCRIPTION

Table III.2: 2005 Operations, CABOS mooring recovery and deployment

Recovery Recovery Recovery Deployment Deployment

Deployment Depth, m Location Time Location Time Depth, m

1120 71° 46.672'N 07-Aug 71° 46.506'N 30-Aug 1121 131° 53.195'W 19:37 UTC 131° 52.711'W 20:01 UTC

99

Figure III.3: Recovered (2004-05) CABOS mooring design and equipment.

100

.

Figure III.4: Deployed (2005-06) CABOS mooring design and equipment (Doug Sieberg’s handwriting).

III.5. A PRELIMINARY LOOK AT MOORING DATA

The MMP was set up to run two profiles per day. The MMP profiled throughout the year until the battery died after ~625th profile (~1 month shy of a full deployment). After profile ~50 the MMP no longer was able to reach the top bumper, but only climbed to 200m for the rest of the deployment; the MMP consistently made it to full depth. The MMP climbed slower and drew more current during the ascents (see Figure III.5 for technical information). This may have been caused by being ballasted heavy.

An example of the MMP record obtained in 2004-05 from the Canadian Basin is shown in Figure III.6. Variable AW layer temperatures are obvious from the record, with a warm anomaly up to 1°C at the beginning of the record which decreased to a minimum less than 0.4°C near day 450. This kind of record will help us to understand the complex nature of the processes occurring in the Arctic Ocean. Many changes in the Canadian Basin are presumably transmitted from “upstream'' locations in the Eurasian Basin, where warm AW enters. As an example, the effects of an influx of anomalously warm AW which entered the Nansen Basin in or around 1989 have been followed around the Arctic Basin, the signal having recently arrived in the Alaskan Beaufort Sea. AWs flow in narrow topographically trapped currents, and are known to be strongly modified by mixing processes as they make their way around the basin. Preliminary look at the MMP record (Figure III.6) suggests that the warm anomaly reached our mooring site.

101

Figure III.5: MMP engineering information

Figure III.6: Water temperature from the CABOS McLane Mooring Profiler (MMP) from August

2004 to September 2005. Blue spaces represent missing data. Strong warm anomaly at the beginning of the record is striking.

Temperature, salinity, and pressure records from the SBE-37 microcat deployed at 54m

depth are shown in Figure III.7. Pressure looks steady during deployment except for the 5m dip around day 490, salinity shows several step-like changes and a decrease during days 370–440,

102

and temperature shows a substantial increase in high-frequency “noise” of unclear nature at the end of the records.

Figure III.7: Temperature (green), salinity (blue), and pressure (red) from SBE-37 (microcat)

deployed at 54m depth from September 2004 to August 2005. Acknowledgements: The mooring operation was led by Doug Sieberg, with much-

appreciated assistance from the WHOI group, the Captain and crew of the CCGS Louis S St-Laurent, and the CTD watchstanders.

103

REFERENCES Aagaard, K., A synthesis of the Arctic Ocean circulation, P.-V. Reun. Cons. Int. Explor. Mer., 188, 11-22, 1989. Abramova, E.N., Composition, abundance and population structure of spring-time zooplankton in the shelf-zone of Laptev Sea. In: Land-Ocean systems in the Siberian Arctic: Dynamics and history. Springer, New-York, 161-168, 1999. Coachman, L. K., and C. A. Barnes, The movement of Atlantic Water in the Arctic Ocean, Arctic, 16, 8-16, 1963. Dmitrenko I., L. Timokhov, O. Andreev, R. Chadwell, M. Dempsey, H. Eicken, S. Kirillov, A. Klein, S. Mastrukov, M. Nitishinskiy, I. Polyakov, M. Ringuette, N. Tanaka, and D. Walsh, Cruise Report of the NABOS-03 Expedition to the Northern Laptev Sea aboard the Icebreaker Kapitan Dranitsyn, September 2003, IARC Technical Report 1, Fairbanks, Alaska, 2004. Fairal C.W., and S.E. Larsen, Inertial-dissipation method and turbulent fluxes at the air-ocean interface, Boundary-layer Meteorol., 34, 287-301, 1986. Fortier, L., P. Sirois, J. Michaud, and D. Barber., Survival of Arctic cod larvae (Boreogadus saida) in relation to sea-ice and temperature in the Northeast Water polynya (Greenland Sea), Canadian Journal of Fisheries and Aquatic Sciences, 63(7), 1608-1616, 2006. Gradinger, R.R., and B.A. Bluhm, In-situ observations on the distribution and behavior of amphipods and Arctic cod (Boreogadus saida) under the sea ice of the High Arctic Canada Basin, Polar Biol. 27, 595–603, 2004. Hanafin, J. A. and P.J. Minnett, Cloud forcing of surface radiation in the North Water Polynya, Atmosphere-Ocean, 39, 239-255, 2001. Haraldsson, C., L. Anderson, M. Hassellöv, S. Hulth, and K. Olsson, Rapid, high-precision potentiometric titration of alkalinity in ocean and sediment pore waters, Deep Sea Research I, 44, 2031-2044, 1997. Harrison, L., J. Michalsky, and J. Berndt, Automated multifilter rotating shadow-band radiometer: an instrument for optical depth and radiation measurements, Appl. Optics, 5118-5125, 1994. Jones, E.P., Circulation in the Arctic Ocean. Polar Research, 29(2), 139-146, 2001. Ivanov, B.V., S. Gerland, J.-G. Winther, and H. Goodwin, Energy exchange processes in the marginal ice zone of the Barents Sea, Arctic Ocean, during spring 1999, Journal of Glaciology, 49(166), 415-419, 2003. Ivanov, V.V., Atlantic Water in the western Arctic, Experience of structured oceanographic investigations in the Arctic Ocean, Edited by A.P. Lisitzin, M.E. Vinogradov and E.A. Romankevich, Moscow, Nauchny Mir, 76-91, 2002. (in Russian) Ivanov, V.V., and A.A. Korablev, Atlantic Water in the Arctic Basin and marginal seas, Formation and dynamics of modern Arctic climate, edited by G.V. Alekseev, St.Petersburg, Hydrometeoizdat, 208-230, 2004. (in Russian) Key, E.L., Cloud Radiative Forcing in Arctic Polynyas: Climatology, Parameterization and Modeling, PhD Thesis, Meteorology and Physical Oceanography, University of Miami, 164 pp., 2004.

104

Key, E.L., and P.J. Minnett, Implications of cloud forcing and feedbacks in the Southern Ocean, Annals of Glaciology, in press, 2006. Grachev, A.A., C.W. Fairal, and S.E. Larsen, On the determination of the neutral drag coefficient in the convective boundary layer, Boundary Layer Meteorology, 86, 257-278, 1998. Kosobokova, K.N., H. Hanssen, H.J. Hirche, and K. Knickmeier, Composition and distribution of zooplankton in the Laptev Sea and adjacent Nansen Basin during summer, 1993. Polar Biology 19, 63-76, 1998. Kosobokova, K.N, and H-J., Hirche, Reproduction of Calanus glacialis in the Laptev Sea, Arctic Ocean, Polar Biology, 24, 33-43, 2001. Lee, K., and F. Millero, Thermodynamic studies of the carbonate system in seawater, Deep Sea

Research I, 42, 2031-2044, 1995. Lewis, E., and D. Wallace, Program developed for CO2 system calculations, ORNIL/CDIAC-105,

1998. Minnett, P.J. and E.L. Key, Meteorology and atmosphere - surface coupling in and around leads and polynyas, Polynyas: Windows into Polar Oceans, W. O. Smith and D. Barber, Eds., Elsevier Oceanography Series, in press, 2006. Mossby, H., Svalbard Waters, Geofysike Publikasjoner 12(4), 1-85, 1938. Novitsky, V.P., Permanent currents of the Northern Barents Sea, Trudy Gosudarstvennogo Okeanograficheskogo Instituta, 64, 1-32, 1961. Translated by U.S.N.O. 1967, Leningrad. Ozhigin, V.K., A.G. Trofimov, and V.A. Ivshin, The Eastern Basin Water and currents in the Barents Sea, ICES C.M. 2000/L:14, 2000. Pfirman, S. L., D. Bauch, and T. Gammelsrod, The Northern Barents Sea: Water mass distribution and modification. In: The Polar Oceans and Their Role in Shaping the Global Environment, 77-94, 1994. Polyakov, I. V., D. Walsh, I. A. Dmitrenko, R. L. Colony, and L. A. Timokhov, Arctic Ocean variability derived from historical observations, Geophys. Res. Lett., 30(6), 1298, 9Hdoi:10.1029/2002GL0164412003, 2003. Quadfasel, D., A. Sy, and B. Rudels, A ship of opportunity section to the North Pole: upper ocean temperature observations, Deep- Sea Res., 40, 777-789, 1993. Reynolds, R.M., M.A. Miller, and M.J. Bartholomew, Design, Operation, and Calibration of a Shipboard Fast-Rotating Shadowband Radiometer, Journal of Atmospheric and Oceanic Technology, 18, 200-214, 2001. Rigor, I. G., J. M. Wallace, and R. L. Colony, Response of sea ice to the Arctic Oscillation, J. Climate, 15, 2648–2663, 2002. Rudels, B., E. P. Jones, L. G. Anderson, and G. Kattner, On the intermediate depth waters of the Arctic Ocean, in: The Polar Oceans and Their Role in Shaping the Global Environment: The Nansen Centennial Volume, Geophys. Monogr. Ser. vol. 85, edited by O. M. Johannessen, R. D. Muench, and J. E. Overland, pp. 33-46, AGU, Washington, D.C., 1994. Rudels, B., G. Björk, R. D. Muench, and U. Schauer, Double-diffusive layering in the Eurasian Basin of the Arctic Ocean. J. Mar. Syst., 21, 3-27, 1999.

105

Schauer, U., R. D. Muench, B. Rudels, and L. Timokhov, Impact of eastern Arctic shelf waters on the Nansen Basin intermediate layers, J. Geophys. Res., 102(C2), 3371-3382, 1997. Schauer, U., Rudels, B., Jones, E. P., Anderson, L. G., Muench, R. D., Björk, G., Swift, J. H., Ivanov, V., and Larsson, A.-M., Confluence and redistribution of Atlantic water in the Nansen, Amundsen and Makarov basins, Annales Geophysicae, 20 (2), 257 – 273, 2002. Smolyanitsky, V., Arctic sea ice climatology for 1950-1994 assessed on the basis of WMO project 'Global Digital Sea Ice Data Bank' Proceedings of the Conference "Mapping and Archiving of Sea Ice Data - the expanding role of radar". WMO/TD, 1027, 2000. Timofeev, V. T., Vodniye Massy Arkticheskogo Basseina (Water masses of the Arctic Basin), GydroMeteoIzdat, Leningrad, 1960. Welch, H.E., Bergmann, M.A., Siferd, T.D., Martin, K.A., Curtis, M.F., Crawford, R.E., Conover R.J., Hop, H., Energy flow through the marine ecosystem of the Lancaster Sound region, arctic Canada, Arctic 45, 343-357, 1992. Woodgate, R. A., K. Aagaard, R. D. Muench, J. Gunn, G. Bjork, B. Rudels, A. T. Roach, and U. Schauer, The Arctic Ocean boundary current along the Eurasian slope and the adjacent Lomonosov Ridge: Water mass properties, transports and transformations from moored instruments, Deep-Sea Research, Part 1, 48, 1757-1792, 2001. Yamamoto-Kawai, M., N.Tanaka, and S. Pivovarov, Freshwater and brine behaviors in the Arctic Ocean deduced from historical data of δ18O and alkalinity (1929 – 2002 A.D.), Journal of Geophysical Research, C10003, 2005.

106

Appendix 1: NABOS-05 STATION LIST (I.Dmitrenko, IARC, and S.Kirillov, AARI) Station Number: KD0105 Date: 10/09/05 Time of beginning: 09:14 dd/mm/yy hh:mm (GMT) Latitude: 81038’N Longitude: 97024’E Depth: 1500/1100 m__ Ice: 0 (navigation chart)

Time, GMT GPS Position Comments 1

Comments 2

#

Research Activity

beginning end beginning end

φ= 81038.0’ φ= 81038.0’ 1 Echo-sounder 09:14 09:38 λ=97024.0’ λ=197019.3’

Depth: 1110

φ= 81038.3’ φ= 81038.8’ 2 CTD/Rosette 09:44 10:22

λ=97022.3’ λ=97010.3’

960 m – counter of winch

Sampling levels: 10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700

φ= 81038.9’ φ= 81039.1’ 3 Net 10:40 10:48 λ=97006.2’ λ=97058.6’

Sampling levels: 0-500 m

φ= 81038.9’ φ= 81039.1’ 4 Bow net 10:40 11:30 λ=97006.2’ λ=97028.6’

φ= 81039.2’ φ= 81038.9’ 5 Tow 11:34 11:41 λ=96057.3’ λ=96056.9’

Station Number: KD0205 Date: 10/09/05 Time of beginning: 03:36 dd/mm/yy hh:mm (GMT) Latitude: 81015’N Longitude: 101010’E Depth: 950/1010 m ___ Ice: 30% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 81081.2’ φ= 81081.2’ 1 Echo-sounder 15:36 15:38 λ=101010.2’ λ=101010.2’

Depth: 1010

φ= 81015.6’ φ= 81016.3’ 2 CTD/Rosette 15:57 16:32

λ=101009.1’ λ=101007.0’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000

φ= 81016.7’ φ= 81017.1’ 3 Net 16:47

17:04 λ=101006.4’ λ=101005.4’

Sampling levels: 0-500 m

φ= 81017.4’ φ= 81017.5’ 4 Bow net 17:17 17:23 λ=101004.4’ λ=101003.5’

100 m

Station Number: KD0305 Date: 10/09/05 Time of beginning: 22:00 dd/mm/yy hh:mm (GMT) Latitude: 81002’N Longitude: 105019’E Depth: >2000 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ=81002.0’ φ=81002.0’ 1 Echo-sounder 22:11 22:13 λ=105019.4’ λ=105019.4’

Depth: >2000 m

1 CTD/ Rosette 22:11 23:20 φ= 81002.0’ φ= 81002.5’ Sampling levels:10, 25, 50, 75, 100, 150,

107

λ=105019.4’ λ=105016.7’ 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, 1500

φ= 81002.6’ φ= 81002.7’ 2 Net 23:34 23:53 λ=105016.4’ λ=105015.9’

Sampling levels: 0-500 m

φ= 81002.6’ φ= 81002.8’ 3 Bow net 23:55 00:00 λ=105016.4’ λ=105015.7’

φ= 81002.8’ φ= 81002.8’ 4 Tow 00:17 00:45 λ=105017.0’ λ=105019.2’

Station Number: KD0405 Date: 11/09/05 Time of beginning: 12:06 dd/mm/yy hh:mm (GMT) Latitude: 80056’N Longitude: 104046’E Depth: 2360 m __ Ice: 20% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 80056.3’ φ= 80056.8’ 1 CTD/Rosette 12:16 13:26

λ=104046.0’ λ=104042.9’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, 1500

φ= 80056.9’ φ= 80057.2’ 2 Net 13:43 14:06 λ=104044.3’ λ=104047.3’

Sampling levels:500-0 m

φ= 80057.2’ φ= 80057.3’ 3 Net 2 14:11 14:17 λ=104041.6’ λ=104041.1’

13 m; Sc 10

φ= 80057.2’ φ= 80056.4’ 4 Tow 14:37 14:50 λ=104044.3’ λ=104047.3’

75 m

Station Number: KD0505 Date: 11/09/05 Time of beginning: 16:18 dd/mm/yy hh:mm (GMT) Latitude: 80050.7’N Longitude: 104020.5’E Depth: 1600 m Ice: 80% (navigation chart)

Time, GMT GPS Position #

Research

Activity beginning end beginning end

Comments 1

Comments 2

φ= 80050.7’ φ= 80051.8’ 1 CTD/Rosette 16:24 17:36 λ=104020.0’ λ=104017.7’

φ= 80052.0’ φ= 80052.2’ 2 Net 17:48 18:05 λ=104016.7’ λ=104014.4’

3 Net 2 21:40 22:00

φ= 80055.0’ φ= 80057.7’ 4 Mooring deployment

01:06 04:41 λ=105007.3’ λ=105000.2’

Station Number: KD0605 Date: 12/09/05 Time of beginning: 08:20 dd/mm/yy hh:mm (GMT) Latitude: 80047.5’N Longitude: 103048.2’E Depth: 1500 m _ Ice: 40% (navigation chart)

Time, GMT GPS Position #

Research

Activity beginning end beginning end

Comments 1

Comments 2

108

φ= 80047.5’ φ= 80047.5’ 1 CTD/ Rosette 08:18 09:12

λ=103048.2’ λ=103049.7’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, 1500

φ= 80047.5’ φ= 80047.5’ 2 Net 09:26 09:44

λ=103050.2’ λ=103050.3’

Sampling levels: 0-500 m

φ= 80047.4’ φ= 80047.4’ 3 Net 2 09:52 09:57 λ=103050.5’ λ=103050.6’

Up to: 80 m

Station Number: KD0705 Date: 12/09/05 Time of beginning: 12:15 dd/mm/yy hh:mm (GMT) Latitude: 80043’N Longitude: 103012’E Depth: 900 Ice: 70% (navigation chart)

Time, GMT GPS Position #

Research

Activity beginning end beginning end

Comments 1

Comments 2

φ= 80043.2’ φ= 80042.8’ 1 CTD/Rosette 12:15 12:45

λ=103012.6’ λ=103014.8’

Sampling levels:10, 25, 50, 75, 100,

150, 200, 250, 300, 350, 400, 500, 600, 700,

800, 850 m φ= 80042.5’ φ= 80042.3’ 2 Net 13:27 13:44 λ=103017.0’ λ=103017.3’

Sampling levels: 500 m

φ= 80042.2’ φ= 80017.5’ 3 Net 2 13:54 13:59 λ=103017.4’ λ=103017.5’

Sampling levels: 60 m

Station Number: KD 08 05 Date: 12/09/05 Time of beginning: 16:12 dd/mm/yy hh:mm (GMT) Latitude: 80034.0’N Longitude: 102003.9’E Depth: 270 m Ice: 80-90% (navigation chart)

Time, GMT* GPS Position #

Research

Activity beginning end beginning end

Comments 1

Comments 2

φ= 80034.0’ φ= 80034.0’ 1 CTD/Rosette 16:14 16:22 λ=102003.9’ λ=102003.1’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250

φ= 80034.2’ φ= 80034.9’ 2 Rosette for filtration

16:42 18:20 λ=102010.4’ λ=102010.8’

φ= 80034.7’ φ= 80034.7’ 3 CTD/Rosette 2 18:24 18:40 λ=102009.0’ λ=102010.3’

φ= 80034.7’ φ= 80034.8’ 4 Net 18:44 18:52 λ=102010.4’ λ=102010.8’

Station Number: KD0905 Date: 12/09/05 Time of beginning: 22:32 dd/mm/yy hh:mm (GMT) Latitude: 80021.8’N Longitude: 101018.8’E Depth: 185 m Ice: 10-20% (navigation chart)

Time, GMT GPS Position # Research

Activity beginning end beginning end

Comments 1

Comments 2

1 CTD/ Rosette 22:40 22:50 φ= 80021.8’ φ= 80021.8’ Sampling

109

λ=101019.5’ λ=101020.3’ levels:10, 25, 50, 75, 100, 150

φ= 80021.8’ φ= 80021.8’ 2 Net 22:57 23:07

λ=101020.6’ λ=101021.4’

φ= 80021.4’ φ= 80021.3’ 3 Net 2 23:11 23:22 λ=101021.8’ λ=101021.8’

φ= 80021.8’ φ= 80021.8’ 4 Mooring deployment

23:30 00:00 λ=101023.4’ λ=101026.0’

φ= 81021.890’ λ=101026.076’

φ= 80020.7’ φ= 80020.5’ 5 Tow 00:42 01:10 λ=101013.0’ λ=101023.1’

Station Number: KD1005 Date: 13/09/05 Time of beginning: 08:55 dd/mm/yy hh:mm (GMT) Latitude: 80004’N Longitude: 106036’E Depth: 1500 m Ice: 80% (navigation chart)

Time, GMT GPS Position # Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 80004.1’ φ= 80004.4’ 2 CTD/Rosette 08:55 09:49

λ=106036.5’ λ=106038.3’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, 1500

Station Number: KD1105 Date: 13/09/05 Time of beginning: 15:45 dd/mm/yy hh:mm (GMT) Latitude: 79023’N Longitude: 109032’E Depth: 1650 m Ice: 30% (navigation chart)

Time, GMT GPS Position #

Research

Activity beginning end beginning end

Comments 1

Comments 2

φ= 79023.1’ φ= 79023.1’ 1 CTD/Rosette 15:44 16:41

λ=109032.3’ λ=109030.8’

Sampling levels:10, 25, 50, 75, 100,

150, 200, 250, 300, 350, 400, 500, 600, 700,

800, 900, 1000, 1250

φ= 79023.2’ φ= 79023.2’ 2 Net 16:55 17:13 λ=109030.3’ λ=109030.8’

Sampling levels: 0-500 m

φ= 79023.2’ φ= 79023.2’ 3 Net 2 17:25 17:27

λ=109030.6’ λ=109030.6’

Sampling levels: 50 m

φ= 79023.3’ φ= 79023.5’ 4 Tow 17:45 18:08 λ=109029.3’ λ=109023.5’

110

Station Number: KD1205 Date: 13/09/05 Time of beginning: 22:21 dd/mm/yy hh:mm (GMT) Latitude: 78047.1’N Longitude: 113014.4’E Depth: 1530 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research

Activity beginning end beginning end

Comments 1

Comments 2

φ= 78047.1’ φ= 78047.1’ 1 CTD/ Rosette 22:34 23:26

λ=113014.7’ λ=113016.5’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000

φ= 78047.1’ Φ= 78047.1’ 2 Net 23:37 23:54

λ=113016.5’ Λ=113015.1’

φ= 78047.4’ Φ= 78047.7’ 3 Tow 00:11

00:28 λ=113016.3’ Λ=113015.1’

Station Number: KD1305 Date: 14/09/05 Time of beginning: 04:24 dd/mm/yy hh:mm (GMT) Latitude: 78014.0’N Longitude: 116043.9’E Depth: 1620 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 78014.0’ Φ= 78014.0’ 1 CTD/Rosette 04:33 05:29 λ=116049.9’ Λ=116049.7’

φ= 78014.0’ Φ= 78013.4’ 2 Net 05:37 05:55

λ=116049.9’ Λ=116049.4’

φ= 78014.0’ Φ= 78013.4’ 3 Net 2 05:40 05:50 λ=116049.9’ Λ=116049.4’

Sampling levels: 60 m

φ= 78013.9’ Φ= 78013.4’ 4 Tow 06:18 06:37 λ=116050.8’ Λ=116052.6’

Station Number: KD 1405 Date: 14/09/05 Time of beginning: 10:15 dd/mm/yy hh:mm (GMT) Latitude: 77041.0’N Longitude: 120000.6’E Depth: 1450 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 77041.0’ Φ= 77040.6’ 1 CTD/Rosette 10:29 11:18

λ=120000.6’ Λ=120000.9’

Sampling levels:10, 25, 50, 75, 100,

150, 200, 250, 300, 350, 400, 500, 600, 700,

800, 900, 1000, 1250

φ=77040.4’ φ=77041.3’ 2 Net 11:27 11:47 λ=120001.4’ Λ=119058.8’

Sampling levels: 70 m

φ=77040.6’ φ=77040.6’ 3 Net 2 11:40 11:45 λ=120001.0’ Λ=120001.0’

111

φ=77040.5’ 4

Tow 12:04 12:27 λ=120000.5’

Station Number: KD1505 Date: 14/09/05 Time of beginning: 15:35 dd/mm/yy hh:mm (GMT) Latitude: 77032’N Longitude: 122056’E Depth: 1650 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research

Activity beginning end beginning end

Comments 1

Comments 2

φ= 77032.0’ Φ= 77031.8’ 1 CTD/Rosette 15:37 16:28

λ=122056.2’ Λ=122057.0’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 77031.7’ Φ= 77031.6’ 2 Net 16:39 16:59 λ=122057.2’ Λ=122057.9’

φ= 77031.9’ Φ= 77031.8’ 3 Net 2 16:57 17:05

λ=122057.3’ Λ=122057.0’

φ= 77031.6’ Φ= 77032.1’ 4 Tow 17:07 17:26 λ=122057.8’ Λ=122057.4’

Station Number: KD1605 Date: 14/09/05 Time of beginning: 22:19 dd/mm/yy hh:mm (GMT) Latitude: 78025.8’N Longitude: 125036.7’E Depth: > 2000 Ice: 50-60% (navigation chart)

Time, GMT GPS Position #

Research

Activity beginning end beginning end

Comments 1

Comments 2

φ= 78025.8’ φ= 78034.8’ 1 CTD/Rosette 22:36 00:31 λ=125036.7’ λ=125034.8’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 78034.3’ φ= 78024.6’ 2 Net 00:45 01:13 λ=125034.3’ λ=125033.5’

φ= 78025.8’ φ= 78034.8’ 3 Net 2 01:00 01:20 λ=125036.7’ λ=125034.8’

φ= 78024.5’ φ= 78034.8’ 4 CTD/Rosette2 01:25 01:35 λ=125033.3’ λ=125034.8’

φ= 78025.8’ 5 Mooring recovery

04:22 06:35 18/09 λ=125036.7’

112

Station Number: KD1705 Date: 15/09/05 Time of beginning: 22:20 dd/mm/yy hh:mm (GMT) Latitude: 78057.7’N Longitude: 126003.5’E Depth: 2900 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research

Activity beginning end beginning End

Comments 1

Comments 2

φ= 78057.0’ φ= 78057.2’ 1 CTD/Rosette 22:19 00:07

λ=126003.5’ λ=126003.0’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, 1250, 1500,1750, 2000, 2250, 2500,2750

φ= 78057.2’ φ= 78057.2’ 2 Net 2 00:05 00:25

λ=126003.0’ λ=126002.6’

φ= 78057.2’ φ= 78057.2’ 3 Net 00:23 00:39 λ=126002.6’ λ=126002.4’

φ= 78057.0’ φ= 78057.3’ 4 Tow 00:46 01:06 λ=126002.3’ λ=125059.0’

Station Number: KD1805 Date: 16/09/05 Time of beginning: 04:10 dd/mm/yy hh:mm (GMT) Latitude: 79022’N Longitude: 125047’E Depth: 3100 m Ice: 20% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 79022.9’ φ= 79022.7’ 1 CTD/Rosette 04:08 05:23 λ=125047.6’ λ=125048.7’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 78022.9’ φ= 78022.7’ 2 Net 2 05:27 05:32 λ=125047.6’ λ=125048.7’

φ= 79022.6’ φ= 79022.7’ 3

Net 05:30 05:35

λ=125049.1’ λ=125049.1’

113

Station Number: KD1905 Date: 16/09/05 Time of beginning: 08:38 dd/mm/yy hh:mm (GMT) Latitude: 79048.8’N Longitude: 126012.6’E Depth: >3000 m Ice: 50% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 79048.8’ φ= 79048.8’ 1 CTD/Rosette 08:44 10:01 λ=126016.6 λ=126012.8’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 79048.8’ φ= 79048.9’ 2 Rosette for filtration

10:12 11:28 λ=126012.8’ λ=126012.4’

φ= 79048.8’ φ= 79048.8’ 3 Net 2 10:30 10:45 λ=126016.6’ λ=126012.8’

φ= 79049.1’ φ= 79048.8’ 4 Rosette 2 11:50 λ=126011.8’ λ=126011.8’

φ= 79049.0’ φ= 79049.9’ 5 Net 12:13 12:40 λ=126011.4’ λ=126011.4’

φ= 79049.1’ φ= 79049.1’ 6 Rosette 3 13:05 13:17 λ=126010.3’ λ=126010.6’

φ= 79048.7’ φ= 79048.7’ 7 Rosette 4 14:01 14:16 λ=126014.4’ λ=126014.8’

φ= 79049.7’ φ= 79048.7’ 8 Tow 14:18 14:50 λ=126012.4’ λ=126014.4’

Station Number: KD2005 Date: 16/09/05 Time of beginning: 16:34 dd/mm/yy hh:mm (GMT*) Latitude: 79049.8’N Longitude: 129019.0’E Depth: >3000 m Ice: 0-10% (navigation chart)

Time, GMT GPS Position # Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 79049.8’ φ= 79049.8’ 1 CTD/Rosette 16:36 17:54 λ=129019.0’ λ=129019.4’

Up to: 1100 m

Station Number: KD2105 Date: 16/09/05 Time of beginning: 21:05 dd/mm/yy hh:mm (GMT) Latitude: 79049’N Longitude: 133023’E Depth: 2000 m Ice: 0% (navigation chart)

Time, GMT GPS Position # Research Activity

beginning end beginning End

Comments 1 Comments 2

φ= 79050.0’ Φ= 79050.3’ 1 CTD/Rosette 21:19 22:32 λ=133023.2’ Λ=133021.9’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

114

φ= 79050.0’ Φ= 79050.3’ 2 Net 2 22:00 22:20 λ=133023.2’ Λ=133021.9’

Sampling levels: 100m

φ= 79050.0’ Φ= 79050.3’ 3 Net 23:41 22:59 λ=133020.2’ Λ=133020.1’

φ= 79050.5’ Φ= 79051.2’ 4 Tow 23:06 23:28 λ=133020.0’ Λ=133021.7’

Station Number: KD2205 Date: 17/09/05 Time of beginning: 03:02 dd/mm/yy hh:mm (GMT) Latitude: 79049.9’N Longitude: 137048.3’E Depth: >2000 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 79049.9’ φ= 79050.4’ 2 CTD/Rosette 03:02 04:22 λ=137048.2’ λ=137046.9’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 79050.4’ φ= 79050.7’ 3 Tow 04:37 04:50 λ=137050.4’ λ=137050.9’

Station Number: KD2305 Data: 17/09/05 Time of beginning: 08:06 dd/mm/yy hh:mm (GMT) Latitude: 80025.6’N Longitude: 140027.0’E Depth: 1600 m Ice: 0% (navigation chart)

Time, GMT* GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 80025.6’ φ= 80025.2’ 1 CTD/Rosette 08:06 09:03 λ=140027.0’ λ=140027.2’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 80025.1’ φ= 80025.2’ 2 Net 09:14 λ=140023.1’ λ=140023.2’

φ= 80024.8’ φ= 80024.6’ 3 CTD/Rosette 2 09:47 09:59 λ=140020.9’ λ=140020.2’

φ= 80024.6’ φ= 80024.6’ 4 Tow 10:08 10:27 λ=140019.5’ λ=140019.5’

φ= 80025.6’ φ= 80025.2’ 5 Net 2 08:45 08:58 λ=140027.0’ λ=140027.2’

115

Station Number: KD2405 Date: 17/09/05 Time of beginning: 11:52 dd/mm/yy hh:mm (GMT) Latitude: 80014.2’N Longitude: 140057.9’E Depth: 1500/1710 Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

1 Echo-sounder Depth: 1710 m

φ= 80014.2’ φ= 80014.1’ 1 CTD/Rosette 11:52 12:55 λ=140057.8’ λ=140052.9’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 80014.2’ φ= 80014.1’ 2 Net 2 12:00 12:25 λ=140057.8’ λ=140052.9’

φ= 80014.2’ φ= 80014.8’ 3 Net 13:01 13:24 λ=140052.6’ λ=140051.2’

φ= 80014.1’ φ= 80014.8’ 4 Tow 13:34 13:53 λ=140050.5’ λ=140052.2’

Station Number: KD2505 Date: 17/09/05 Time of beginning: 15:15

dd/mm/yy hh:mm (GMT) Latitude: 80002.0’N Longitude: 141048.0’E Depth: 1650 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1 Comments 2

φ= 80001.7’ φ= 80001.8’ 1 CTD/Rosette 15:23

16:17 λ=141047.8’ λ=141047.5’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 80002.0’ φ= 80002.7’ 2 Net 16:29

16:47

λ=141047.7’ λ=141048.0’

φ= 80002.0’ φ= 80002.7’ 3 Tow 16:59 17:18 λ=141047.7’ λ=141049.1’

116

Station Number: KD2605 Date: 17/09/05 Time of beginning: 18:20 dd/mm/yy hh:mm (GMT) Latitude: 79055.6’N Longitude: 142019.7’E Depth: 1330 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 79055.5’ φ= 79055.0’ 1 CTD/Rosette 18:23 19:11 λ=142019.6’ λ=142018.1’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000

φ= 79055.5’ φ= 79055.0’ 2 Net 2 18:45 19:00

λ=142019.6’ λ=142018.1’

Sampling levels: 100 m

φ= 79054.9’ φ= 79055.3’ 3 Net 19:00 19:39 λ=142017.9’ λ=142017.5’

φ= 79054.8’ φ= 79054.8’ 4 Rosette for filtration

19:55

λ=142017.1’ λ=142017.1’

φ= 79055.9’ φ= 79054.3’ 5 Mooring recovery

21:14 00:05 λ=142020.6’ λ=142008.3’

φ= 79054.2’ φ= 79055.1’ 6 Tow 00:17 00:46 λ=142005.2’ λ=142005.1’

Station Number: KD2705 Date: 18/09/05 Time of beginning: 02:33 dd/mm/yy hh:mm (GMT) Latitude: 79035.2’N Longitude: 142024.1’E Depth: 1170 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 79035.1’ φ= 79035.4’ 1 CTD/Rosette 02:33 03:15 λ=142024.7’ λ=142021.4’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000

φ= 79035.1’ φ= 79035.4’ 2 Net 2 01:40 02:55

λ=142024.7’ λ=142021.4’

Sampling levels: 100 m

φ= 79035.4’ φ= 79035.5’ 3 Net 03:20 03:38 λ=142021.4’ λ=142020.5’

φ= 79035.7’ φ= 79035.2’ 4 Tow 03:45 04:03 λ=142020.4’ λ=142020.7’

117

Station Number: KD2805 Date: 18/09/05 Time of beginning: 05:24 dd/mm/yy hh:mm (GMT) Latitude: 79025.1’N Longitude: 143000.2’E Depth: 540 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 79025.1’ φ= 79025.4’ 1 CTD/Rosette 05:24 05:41 λ=143000.2’ λ=143000.0’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500

φ= 79025.0’ φ= 79025.0’ 2 Net 2 05:45 06:00 λ=142059.9’ λ=142059.8’

Sampling levels:

0, 20, 25, 48, 50m

φ= 79025.0’ φ= 79025.0’ 3 Net 05:48 06:53 λ=142059.9’ λ=142059.8’

Up to: 500 m

φ= 79025.0’ φ= 79025.2’ 4 Tow 06:24 06:53 λ=142059.7’ λ=143004.5’

Station Number: KD2905 Date: 18/09/05 Time of beginning: 07:53 dd/mm/yy hh:mm (GMT) Latitude: 79015.1’N Longitude: 143029.2’E Depth: 200 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 79015.2’ φ= 79015.2’ 1 CTD/Rosette 07:57 08:03 λ=143029.3’ λ=143029.3’

Sampling levels:10, 25, 50, 75, 100,

150, 200 φ= 79015.2’ φ= 79015.2’ 2 Net 2 08:00 08:15 λ=143029.3’ λ=143029.3’

Sampling levels: 100 m

φ= 79015.2’ φ= 79029.0’ 3 Net 08:14 08:24 λ=143029.2’ λ=143029.0’

φ= 79029.0’ φ= 79015.9’ 4 Tow 08:27 08:57 λ=143029.9’ λ=143032.5’

Station Number: KD3005 Data: 18/09/05 Time of beginning: 10:25 dd/mm/yy hh:mm (GMT) Latitude: 79000.1’N Longitude: 143058.2’E Depth: 90 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 79000.1’ φ= 79000.1’ 1 CTD/Rosette 10:34 10:44 λ=143059.3’ λ=143058.9’

Sampling levels:10, 25, 50, 75

φ= 79000.1’ φ= 79000.1’ 2 Net 2 10:45 10:59 λ=143059.3’ λ=143058.9’

Sampling levels: 100 m

φ= 79000.1’ φ= 79000.8’ 3 Net 10:50 10:55 λ=143058.4’ λ=143059.2’

φ= 79000.2’ φ= 79000.2’ 4 Tow 10:59 11:15 λ=143058.4’ λ=143059.2’

118

Station Number: KD3105 Date: 19/09/05 Time of beginning: 00:41 dd/mm/yy hh:mm (GMT) Latitude: 79025.1’N Longitude: 139048.9’E Depth: 1820 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 79025.1’ φ= 79025.5’ 1 CTD/Rosette 00:41 01:51 λ=139048.9’ λ=139046.8’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 79025.1’ φ= 79025.1’ 2 Net 2 00:40 00:55 λ=139048.9’ λ=139048.9’

Sampling levels: 100 m

φ= 79025.5’ φ= 79025.6’ 3 Net 01:57 02:15 λ=139046.8’ λ=139047.0’

φ= 79025.8’ φ= 79026.6’ 4 Tow 02:22 02:44 λ=139046.7’ λ=139046.6’

Station Number: KD3205 Date: 19/09/05 Time of beginning: 05:30 dd/mm/yy hh:mm (GMT) Latitude: 79000.0’N Longitude: 137040.8’E Depth: 1700 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 79000.0’ φ= 79000.0’ 1 CTD/Rosette 05:36 06:37 λ=137040.8’ λ=137041.3’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 79000.0’ φ= 79000.0’ 2 Net 2 05:45 06:10 λ=137040.8’ λ=137041.0’

Sampling levels: 100 m

φ= 79000.0’ φ= 79000.0’ 3 Net 06:47 07:33 λ=137041.1’ λ=137040.6’

φ= 78059.9’ φ= 78059.3’ 4 Tow 07:13 07:33 λ=137041.3’ λ=137041.3’

Station Number: KD3305 Date: 19/09/05 Time of beginning: 09:55 dd/mm/yy hh:mm (GMT) Latitude: 78040.2’N Longitude: 135030.1’E Depth: > 2000 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 78040.2’ φ= 78041.0’ 1 CTD/Rosette 10:01 11:05 λ=135030.1’ λ=135026.5’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

119

φ= 78040.1’ φ= 78040.1’ 2 Net 2 10:25 10:45 λ=135030.1’ λ=135030.1’

Sampling levels: 100 m

φ= 78041.1’ φ= 78041.6’ 3 Net 11:16 11:39 λ=135025.7’ λ=135023.5’

φ= 78041.8’ φ= 78041.6’ 4 Tow 11:48 12:11 λ=135022.4’ λ=135027.3’

Station Number: KD3405 Date: 19/09/05 Time of beginning: 15:35 dd/mm/yy hh:mm (GMT) Latitude: 78029.7’N Longitude: 132058.1’E Depth: > 2000 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 78029.7’ φ= 78029.0’ 1 CTD/Rosette 15:35 18:58 λ=132058.1’ λ=132059.4’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

Station Number: KDMID05 Date: 20/09/05 Time of beginning: 11:50 dd/mm/yy hh:mm (GMT) Latitude: 78025.8’N Longitude: 125043.0’E Depth: 120 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 78025.8’ φ= 78028.5’ 1 Mooring deployment

11:51 16:46 λ=125043.0’ λ=125040.8’

Station Number: KD3505 Date: 20/09/05 Time of beginning: 18:30 dd/mm/yy hh:mm (GMT) Latitude: 78029.9’N Longitude: 125043.3’E Depth: 2400 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 78029.9’ φ= 78030.6’ 1 CTD/Rosette 18:32 19:50 λ=125043.4’ λ=125043.3’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

120

Station Number: KD3605 Date: 20/09/05 Time of beginning: 22:15 dd/mm/yy hh:mm (GMT) Latitude: 78006.4’N Longitude: 126004.2’E Depth: 2000 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 78006.4’ φ= 78006.6’ 1 CTD/Rosette 22:14 λ=126004.2’ λ=126059.7’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 78006.4’ φ= 78006.4’ 2 Net 2 00:15 00:25 λ=126004.2’ λ=126004.2’

Sampling levels: 100 m

φ= 78006.6’ φ= 78006.8’ 3 Net 00:10 λ=126059.7’ λ=125058.2’

φ= 78006.8’ φ= 78006.2’ 4 Tow 00:35 00:56 λ=125057.5’ λ=125058.2’

Station Number: KD3705 Date: 21/09/05 Time of beginning: 02:58 dd/mm/yy hh:mm (GMT) Latitude: 77044.1’N Longitude: 125059.7’E Depth: >2000 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning End

Comments 1

Comments 2

φ= 77044.3’ φ= 77045.4’ 1 CTD/Rosette 03:16 04:23 λ=125059.0’ λ=125058.0’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

φ= 77045.7’ φ= 77046.1’ 2 Net 04:33 05:00 λ=125056.2’ λ=125057.3’

φ= 77045.7’ φ= 77045.7’ 3 Net 2 05:03 05:18 λ=125056.2’ λ=125056.2’

Sampling levels: 110 m

φ= 77046.6’ φ= 77046.0’ 4 Tow 05:38 06:09 λ=125056.3’ λ=125059.9’

Station Number: KD3805 Date: 21/09/05 Time of beginning: 07:31 dd/mm/yy hh:mm (GMT) Latitude: 77030.4’N Longitude: 126000.2’E Depth: 1770 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 77030.2’ φ= 77030.9’ 1 CTD/Rosette 07:41 08:43 λ=126000.1’ λ=126000.1’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 1500

121

φ= 77031.0’ φ= 77031.2’ 2 Net 08:53 09:13 λ=125059.6’ λ=125059.3’

φ= 77031.2’ φ= 77031.2’ 3 Net 2 09:19 09:32 λ=125059.1’ λ=125059.1’

Sampling levels: 90 m

φ= 77031.2’ φ= 77030.4’ 4 Tow 09:33 10:02 λ=126000.4’ λ=126004.2’

Station Number: KD3905 Date: 21/09/05 Time of beginning: 11:20 dd/mm/yy hh:mm (GMT) Latitude: 77020.4’N Longitude: 125059.2’E Depth: 1200 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 77020.4’ φ= 77021.2’ 1 CTD/Rosette 11:22 12:06 λ=125059.3’ λ=125051.5’

Sampling levels:10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000

φ= 77021.4’ φ= 77021.8’ 2 Net 12:17 12:37 λ=125057.0’ λ=125057.9’

φ= 77021.2’ φ= 77021.2’ 3 Net 2 12:44 12:55 λ=125055.8’ λ=125055.8’

Sampling levels: 90 m

φ= 77022.0’ φ= 77021.5’ 4 Tow 12:55 13:20 λ=125056.2’ λ=125057.9’

Station Number: KD4005 Date: 21/09/05 Time of beginning: 15:00 dd/mm/yy hh:mm (GMT) Latitude: 77003.4’N Longitude: 126000.9’E Depth: 120 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 77003.4’ φ= 77003.4’ 1 CTD/Rosette 15:04 15:15 λ=126000.9’ λ=126000.9’

Sampling levels:10, 25, 50, 75, 100

φ= 77003.8’ φ= 77004.0’ 2 Net 15:20 15:27 λ=126001.8’ λ=126002.2’

φ= 77005.1’ φ= 77006.8’ 3 Pumping 16:05 17:14 λ=126005.1’ λ=126011.9’

φ= 77006.9’ φ= 77006.9’ 4 2nd cast 17:35 λ=126014.0’ λ=126014.0’

φ= 77007.2’ φ= 77006.4’ 5 Tow 17:59 18:22 λ=126016.5’ λ=126018.9’

122

Station Number: KD4105 Date: 21/09/05 Time of beginning: 20:40 dd/mm/yy hh:mm (GMT) Latitude: 76044.5’N Longitude: 126000.9’E Depth: 120 m Ice: 0% (navigation chart)

Time, GMT GPS Position #

Research Activity

beginning end beginning end

Comments 1

Comments 2

φ= 76044.5’ φ= 76044.4’ 1 CTD/Rosette 20:41 20:51 λ=126000.9’ λ=125096.0’

Sampling levels:10, 25, 50, 75, 100

φ= 76043.7’ 2 Mooring

deployment 21:41

λ=125055.3’

φ= 76043.6’ 3 Net 21:51 λ=125055.2’

φ= 77005.1’ 4 Net 2 22:02 λ=125055.2’

φ= 76043.3’ φ= 76042.9’ 5 Tow 22:10 22:28 λ=125054.8’ λ=125054.0’

123

Appendix 2: Summary table of locations at the beginning and end of each LADCP cast. The notes section indicates wire-angle present during the cast (P.Lazarevich, FSU)

Beginning of cast End of cast Station Number

Date Time (GMT)

Latitude S Deg. Min.

Longitude E Deg. Min.

Date Time (GMT)

Latitude S Deg. Min.

Longitude E Deg. Min.

Notes

01 09/10/05 09:44:33 81 38.49 097 18.77 09/10/05 10:22:15 81 38.80 097 10.54 severe wire angle 02 09/10/05 15:53:49 81 15.60 101 09.16 09/10/05 16:31:50 81 16.39 101 07.07 moderate wire

angle 03 09/10/05 22:11:35 81 02.00 105 19.43 09/10/05 23:20:37 81 02.55 105 16.75 slight wire angle 04 09/11/05 12:17:43 80 56.38 104 46.09 09/11/05 13:26:45 80 56.82 104 42.93 slight wire angle 05 09/11/05 16:26:01 80 50.78 104 20.06 09/11/05 17:36:54 80 51.85 104 17.38 water leak after

cast 8a 09/12/05 16:14:56 80 34.00 102 03.90 09/12/05 16:23:55 80 34.07 102 04.18 moderate wire

angle 8b 09/12/05 18:24:27 80 34.74 102 08.07 09/12/05 18:34:28 80 34.75 102 09.70 moderate wire

angle 09 09/12/05 22:40:25 80 21.88 101 19.55 09/12/05 22:45:55 80 21.89 101 19.98 10 09/13/05 08:55:17 80 04.13 106 36.51 09/13/05 09:49:52 80 04.41 106 38.36 moderate wire

angle 11 09/13/05 15:44:55 79 23.20 109 32.40 09/13/05 16:40:32 79 23.17 109 30.82 moderate wire

angle 12 09/13/05 22:34:50 78 47.16 113 14.82 09/13/05 23:26:10 78 47.16 113 16.57 13 09/14/05 04:34:43 78 14.05 116 49.98 09/14/05 05:29:49 78 14.03 116 49.78 14 09/14/05 10:30:01 77 41.08 120 00.66 09/14/05 11:19:13 77 40.77 120 00.99 15 09/14/05 15:36:13 77 32.04 122 56.26 09/14/05 16:27:09 77 31.81 122 57.07 16 09/14/05 22:27:00 78 25.87 125 36.77 09/15/05 00:35:20 78 24.87 125 34.77 slight wire angle 17 09/15/05 22:18:33 78 57.07 126 03.56 09/16/05 00:07:50 78 57.27 126 03.02 slight wire angle 18 09/16/05 04:11:53 79 22.93 125 47.67 09/16/05 05:24:27 79 22.72 125 48.74 19 09/16/05 08:44:43 79 48.87 126 12.68 09/16/05 09:58:17 79 48.89 126 12.90 20 09/16/05 16:39:40 79 49.86 129 19.15 09/16/05 17:53:47 79 49.84 129 19.43 moderate wire

angle 21 09/16/05 21:18:50 79 50.05 133 23.46 09/16/05 22:32:20 79 50.38 133 21.92 22 09/17/05 03:02:45 79 49.90 137 48.29 09/17/05 04:16:05 79 50.35 137 46.96 moderate wire

angle 23 09/17/05 08:07:44 80 25.65 140 27.07 09/17/05 09:03:28 80 25.27 140 23.79 moderate wire

angle 24 09/17/05 11:52:08 80 14.25 140 57.88 09/17/05 12:49:22 80 14.20 140 57.42 moderate wire

angle 25 09/17/05 15:23:53 80 01.78 141 47.86 09/17/05 16:17:30 80 01.81 141 47.59 26 09/17/05 18:26:03 79 55.57 142 19.40 09/17/05 19:11:00 79 55.07 142 18.11 severe wire angle 27 09/18/05 02:32:51 79 35.17 142 24.14 09/18/05 03:09:12 79 35.40 142 22.00 slight wire angle 28 09/18/05 05:23:48 79 25.14 143 00.26 09/18/05 05:41:23 79 25.11 143 00.07 slight wire angle

124

29 09/18/05 07:59:20 79 15.27 143 29.36 09/18/05 08:06:08 79 15.28 143 29.29 30 09/18/05 10:36:30 79 00.12 143 59.35 09/18/05 10:41:40 79 00.11 143 59.13 31 09/19/05 00:43:24 79 25.16 139 48.84 09/19/05 01:48:30 79 25.51 139 46.88 using new battery 32 09/19/05 05:36:25 79 00.05 137 40.86 09/19/05 06:37:45 79 00.08 137 41.37 slight wire angle 33 09/19/05 10:03:42 78 40.31 135 30.16 09/19/05 11:09:04 78 41.06 135 26.31 severe wire angle 34 09/19/05 15:42:52 78 30.00 130 00.09 09/19/05 18:42:10 78 34.28 130 15.39 severe weather 36 09/20/05 22:14:40 78 06.44 126 04.28 09/20/05 23:29:00 78 06.63 126 04.79 moderate wire

angle 37 09/21/05 03:17:55 77 44.40 125 59.04 09/21/05 04:23:48 77 45.52 125 58.00 38 09/21/05 07:44:25 77 30.14 126 00.19 09/21/05 08:45:15 77 30.95 125 59.86 moderate wire

angle 39 09/21/05 11:22:07 77 20.46 125 59.32 09/21/05 12:06:40 77 21.25 125 57.52 moderate wire

angle

125

Appendix 3: RV Lance cruise log 28.8 At 12:30, after the ship’s crew went to vote at the sysselsmann’s office, we left Longyearbyen and went steaming towards the position of mooring F11. 29.8 In the morning we arrived at the position of mooring F11. The releaser could not be heard but it responded and the mooring was recovered successfully. After the recovery we started the CTD section. Shortly afterwards we encountered heavy ice. At 14:30 we were near, but not on, position F12, but there was too much ice for mooring recovery. 30.8 In the morning we arrived at position F13. We heard no response from the releaser and there was too much ice to release the mooring without hearing the releaser, especially because at least the upper part is known to be missing. We were able to locate the releaser, but we had to wait some hours before releasing the mooring because we had to wait for an opening in the ice large enough to allow us to pass over the mooring. In the evening we successfully recovered F14. 31.8 In the morning we recovered mooring F17 without problems. We reached the position of F18 but heard no response from the releaser. As there was enough open water we did send the release signal, but the mooring did not surface. We then started to move in the drift direction to search for the mooring and to listen for the releaser because the whole mooring could have been dragged to a new position by an iceberg. Our search was not successful. We continued the CTD section towards F19. 1.9 After encountering heavy ice on the way, in the late morning we reached mooring position F19 and also the westernmost point of the CTD section. At the site we found at least 80% ice coverage and very thick ice floes; floes were generally thicker than 4-5m, and some were more then 10m thick. As was true last year, there were many icebergs to the north of the site (mostly grounded). In addition there were icebergs to the south, and floating icebergs at almost the mooring latitude. No contact was possible with the F19 releaser. The best we could do under these ice conditions was to try to find the mooring with the echo sounder. We saw some ambiguous signals that could have been reflections from the tube, but no clear signal. As recovery was not possible in such a situation, we made no attempt to release the mooring. We also had only 5 tube segments and 30 flotations (about 60 kg of uplift); therefore, we also could not deploy a new mooring. After an ice station we left for mooring position F18 along a short CTD transect along 78N44. 2.9 We encountered extensive ice cover throughout most of the day, which got just a little bit better for some hours during midday. In the afternoon we reached mooring position F18 but extensive ice cover did not allow us to drag for the mooring. 3.9 Reached position F17 and deployed the mooring, then headed towards position F14 and deployed that mooring in the afternoon. Starting at F14 going eastward we resumed the CTD work on the main Fram Strait section. 4.9 Very extensive ice in the morning, almost 100%, as the small leads between floes were covered with new ice. Floes were estimated to be 1-2m in thickness. Under these conditions there was no possibility of releasing or dredging for mooring F13, but the new F13 could be deployed after we made a larger opening in the ice with the ship. For a few hours after mooring deployment the ice cover was so high (>98%) that the ship made almost no progress, but mainly drifted south-southwestward with the ice. At 22:00 hours the wind increased, the tide changed, and the ice became more open, so that better progress was possible. 5.9

126

Heavy ice again during the early morning, but the situation improved and later we reached the ice edge south of F12. After some hours of steaming we reached position F12, which was ice free. F12 could not be seen on the echo sounder nor could the releaser be heard. The release signal was sent, but no mooring surfaced. Dredging for the mooring was also unsuccessful. In the evening the new F12 mooring was deployed. After this the CTD work was continued. 6.9 Around noon we met Polarstern. The crew had deployed their last mooring and she was on her way to the Greenland coast. Three people were picked up from Lance with the helicopter from Polarstern for a visit there, while one person from the Polarstern was visiting Lance. It is agreed that if Polarstern finds favorable ice conditions at F19 they will try to recover the mooring. During the Polarstern visit F11 was deployed. Afterwards the CTD transect towards Ny Ålesund was continued. 7.9 All day taking CTD casts on the transect towards Ny Ålesund. 8.9 The work on the CTD transect continues. Shortly before arriving at Ny Ålesund, we saw a walrus on a beach on Prins Karls Forlandet. At 15:30 we arrived at Ny Ålesund. Harvey and Angelica left the ship, as no ice work was planned for the next leg. There was also some unloading and loading of cargo. Edmond mailed to inform us we probably had the wrong position for F18; I checked in the ship’s log from last year and he is right. I then sent a notice to Polarstern to ask if they could pick up this mooring at the correct position, although they probably had passed it already. Departure from Ny Ålesund was at 24:00. 9.9 The five last CTD casts of the 79N section were taken and then we started to steam towards the NABOS mooring position. The route passed through Smeerenburg Fjorden, where we met Jan Mayen. After passing Nordkapp, we encountered first ice in the evening. 10.9 The morning begins with low visibility and ice cover with large open spaces. The wind is strong (8 Beaufort) but due to the ice and the wind direction (northwesterly winds) the sea is quite calm. During the morning the wind decreases. The ice conditions are large ice flows, at times quite ridged, separated by open water. The leads that are comfortably wide for Lance are mostly in an east-west direction, but to the north the leads are getting smaller or disappearing; therefore not much progress is made to the north. After noon we decided to make the first CTD section towards Kvitøya and then try again tomorrow to reach the mooring position. 11.9 At about 1:00 AM the last CTD on the section towards Kvitøya was taken and we again turned north to try to reach the mooring. There was ice almost all the way to Kvitøya, which in respect to the state of the sea was good; in the morning the mean wind speed reached 27 m/s, in gusts over 30m/s, but due to the presence of ice the sea was relatively calm. In the afternoon, with still 38 nm to go to the NABOS mooring, it was decided that due to the minimal possibility of reaching the mooring we should not try to proceed further towards the mooring. At this moment the ice floes were large (often >1km) and ridged, so Lance could not break through them and the only open lead was in the southerly direction. In the other directions only small pieces of open water could be distinguished. Even with a very optimistic assumption of 2 knots it would take 19 hours to reach the position, and with some waiting for a clear area over the mooring and the way back taking at least the same amount of time, we would need more time then is left. After this decision a CTD transect towards Storøya was started, followed by a section towards Kvitøya. 12.9 In the morning the section towards Kvitøya was finished and the monument to Andree, Strindberg and Frænkel on Kvitøya was visited. Then a CTD section towards Kong-Karls land was done. 13.9 We continued the CTD work, first to the southeast, then in a southwesterly direction towards Hopen. 14.9

127

The CTD work was finished early in the morning. After breakfast we paid a visit to the meteorological station on Hopen. At 12:00 we left for the first sound source mooring to be recovered, with a planned arrival time in the late afternoon on the 15th. 15.9 First sound source mooring recovered at 17:00. CTD calibration mooring is carried out between 19:00 and 21:00. 16.9 Second sound source mooring recovered at 7:00. The third sound source mooring recovered at 16:30. Started steaming to Tromso. 17.9 Arrived at Tromso at 10:00 AM.

128

Appendix 4: RV Lance stations list N st Day Month Year Hr:min LatºN LonºE Depth,m

55 10 9 2005 9:19 81.250 31.183 209 56 10 9 2005 12:46 81.167 31.450 170 57 10 9 2005 13:44 81.067 31.217 150 58 10 9 2005 14:56 80.983 30.567 130 59 10 9 2005 16: 4 80.900 30.617 125 60 10 9 2005 16:58 80.833 30.700 112 61 10 9 2005 17:45 80.750 30.933 128 62 10 9 2005 18:45 80.667 31.000 205 63 10 9 2005 19:50 80.567 30.967 158 64 10 9 2005 21: 4 80.483 30.900 178 65 10 9 2005 21:56 80.417 30.967 233 66 10 9 2005 22:48 80.333 30.983 108 67 11 9 2005 13:54 81.000 29.900 132 68 11 9 2005 14:46 80.917 29.733 220 69 11 9 2005 15:39 80.850 29.550 307 70 11 9 2005 16:49 80.767 29.400 469 71 11 9 2005 17:55 80.700 29.650 431 72 11 9 2005 19:19 80.633 29.383 349 73 11 9 2005 20:41 80.583 28.917 227 74 11 9 2005 21:47 80.500 28.750 375 75 11 9 2005 23:17 80.433 28.567 52 76 12 9 2005 0:10 80.333 28.333 56 77 12 9 2005 0:59 80.233 28.417 50 78 12 9 2005 1:45 80.250 28.817 217 79 12 9 2005 2:35 80.233 29.233 243 80 12 9 2005 3:22 80.233 29.667 247 81 12 9 2005 4: 9 80.250 30.083 255 82 12 9 2005 4:57 80.233 30.500 185 83 12 9 2005 5:35 80.250 30.917 177 84 12 9 2005 11:51 80.150 29.483 370 85 12 9 2005 12:40 80.067 29.417 330 86 12 9 2005 13:33 80.000 29.333 297 87 12 9 2005 14:23 79.900 29.267 327 88 12 9 2005 15:14 79.817 29.183 288 89 12 9 2005 16: 6 79.750 29.117 243 90 12 9 2005 17: 1 79.667 29.033 313 91 12 9 2005 17:52 79.583 28.967 334 92 12 9 2005 18:47 79.483 28.900 341 93 12 9 2005 19:40 79.417 28.833 298 94 12 9 2005 20:35 79.317 28.783 272 95 12 9 2005 21:23 79.250 28.700 210 96 12 9 2005 22:17 79.150 28.633 198 97 12 9 2005 23: 3 79.067 28.550 121 98 12 9 2005 23:54 79.000 28.483 23 99 13 9 2005 3:29 79.000 30.983 220 100 13 9 2005 4:49 78.817 31.100 144 101 13 9 2005 6: 6 78.667 31.217 281 102 13 9 2005 7:23 78.483 31.350 288 103 13 9 2005 8:39 78.317 31.450 238 104 13 9 2005 9:54 78.167 31.567 203

129

105 13 9 2005 11: 9 78.000 31.667 217 106 13 9 2005 12:24 77.817 31.767 174 107 13 9 2005 13:44 77.667 31.883 167 108 13 9 2005 15: 0 77.483 31.983 155 109 13 9 2005 16:23 77.400 31.250 190 110 13 9 2005 17:46 77.317 30.517 190 111 13 9 2005 19:19 77.250 29.783 196 112 13 9 2005 20:45 77.150 29.050 190 113 13 9 2005 22: 6 77.067 28.333 190 114 13 9 2005 23:27 76.983 27.617 116 115 14 9 2005 0:43 76.917 26.900 112 116 14 9 2005 1:58 76.817 26.200 70 117 14 9 2005 3:15 76.750 25.483 30

130

Appendix 5: Abstracts of 2005 IARC Summer School aboard Kapitan Dranitsyn THE ROLE OF SNOW AND ICE IN THE GLOBAL CLIMATE SYSTEM Roger G.Barry, National Snow and Ice Data Center, Boulder, CO, USA

Global snow and ice cover (the "cryosphere") plays a major role in global climate and hydrology through a range of complex interactions and feedbacks, the best known of which is the ice–albedo feedback. Snow and ice cover undergo marked seasonal and long-term changes in extent and thickness. In the Proterozoic era, for example, a long-lived "snowball" Earth has been proposed, while in the Pleistocene epoch, glacial and interglacial intervals alternated in a quasi-periodic manner, but with a smaller spatial extent. The perennial elements of the cryosphere – the major ice sheets and permafrost - play a role in present-day regional and local climate and hydrology, but the large seasonal variations in snow cover, frozen ground, and sea ice are of importance on continental to hemispheric scales. The characteristics of these variations, especially in the Northern Hemisphere, and evidence for recent trends in snow cover, seasonally frozen ground, and ice extent are discussed. The relative roles of natural variability in the climate-system forcing of such trends, versus possible anthropogenic influences, cannot yet be confidently separated. However, continued careful monitoring and assessment of the likely causes and the possible consequences of such changes is clearly a vital task for scientists studying climate-cryosphere processes. The World Climate Research Programme has recently established a new project focusing on Climate and the Cryosphere (CliC) that seeks to understand the role of the cryosphere in the climate system. Barry, R. G. 2002. The role of snow and ice in the global climate system. Polar Geography 24(3): 235-46. ARCTIC CLIMATE Roger G.Barry, National Snow and Ice Data Center, Boulder, CO, USA

An overview is presented of seasonal atmospheric circulation features and their expression in regional climatic contrasts. After outlining the various characteristics that can be used to define the Arctic geographically, historical concepts of the atmospheric circulation and the lack of adequate observational data until the 1950s are noted. Synoptic information over the Arctic Ocean is only reliable after the establishment of the Arctic buoy program in 1979.

The seasonal mean pressure and 500-mb (or hPa) geopotential height fields illustrate the main centers of action (Icelandic and Aleutian lows, Siberian winter high). The subpolar oceanic loci of cyclone frequency and cyclogenesis are then examined. The large-scale surface energy budgets, and the influences of surface albedo and cloud cover, are then described, followed by fields of temperature and precipitation. Problems of precipitation measurement, especially for solid precipitation, are noted. Finally, maritime and continental Arctic climatic conditions are described for representative stations. Serreze, M.C. and Barry, R.G. 2005. The Arctic Climate System, Cambridge Univ Press. (Chapters 2, 4). HISTORY OF ARCTIC EXPLORATION AND CLIMATE PROGRAMS Roger G.Barry, National Snow and Ice Data Center, Boulder, CO, USA

Exploration of the Arctic in the 15-17th centuries was motivated primarily by the search for a trade route to China (Cathay) via a Northeast or Northwest Passage. Voyages of the Dutch sailor W. Barents in the east and English sailors like M. Frobisher, J. Davis and H. Hudson exemplify this period. Late Medieval maps show widely differing concepts of the Arctic Ocean. Major Russian expeditions traveled across Siberia and then used the rivers to reach the coast (S. Dezhnev) or sailed north and eastward in the Bering Sea (V. Bering). New information was often not provided to map makers; sometimes it was lost, or it was disbelieved and ignored.

Sealers and whalers such as W. Scoresby Jr. often had extensive knowledge of North Atlantic ice conditions, but persistent beliefs in an open Arctic Sea led to many attempts to sail

131

to the North Pole. In the 19th century, the British Navy made a sustained effort to locate a NW Passage and

the associated Franklin search expeditions mapped most of the Canadian Arctic Archipelago. Efforts to reach the Pole provided a rationale for many late 19th century expeditions. Around 1850 scientific interests were energized by new instruments and methods. The First International Polar Year (IPY) 1882-3 was a landmark international endeavor, which was repeated with more nations, participants and fields of science involved in the second IPY 1932-3, the 1957-8 International Geophysical Year (IGY) and the planned 2007-8 third IPY.

Ice-ocean-climate research highlights include: Nansen’s Fram drift, Soviet North Pole Drifting Stations and US ice island stations, submarine sonar ice draft measurements, drifting buoys, and since the 1970s, satellite remote sensing of sea ice as well as atmospheric and ocean variables. Barry, R.G. 2005. Climate research programmes. In M. Nuttall (ed), Encyclopedia of the Arctic, Vol. 1. Routledge. London. pp. 379-83. Serreze, M.C. and Barry, R.G. 2005. The Arctic Climate System, Cambridge Univ Press. (Chapter 1). PALEOCLIMATIC HISTORY AND RECENT CLIMATE CHANGE IN THE ARCTIC Roger G.Barry, National Snow and Ice Data Center, Boulder, CO, USA

A brief review is presented of the geologic evolution of the Arctic Basin and its climate over the last 60 Ma and the contrast with Antarctica in the Miocene-Pliocene is noted. The approximate dates of initial glaciation, permafrost formation and perennial sea ice cover in the Arctic are summarized. The types of marine, terrestrial and ice core evidence for paleoclimatic reconstruction are outlined. The contrasting orbital signatures during the last 2 Ma (41 ka prior to 0.8 Ma and 100 ka) is pointed out and the intensification of the glacial-interglacial cycles and shorter interglacials since 430 ka, demonstrated by the EPICA core, is shown. The extent of land ice and ice shelves in the Arctic during the Last Glacial Maximum is discussed. The variability of conditions in the North Atlantic over the last 60 ka shown by the IRD record (Heinrich events), the ca. 1470 yr record of Dansgaard-Oeschger oscillations in the GISP=GRIP Greenland ice cores, and the final Younger Dryas cold event are briefly noted.

The climatic records (temperature and precipitation) of the last 100 years in northern high latitudes are then presented, showing the strong recent warming over northern continents and regional cooling over eastern Canada-southern Greenland. This is followed by more detailed information for the last 30-40 years including runoff, snow cover, and sea ice. Advanced Very High Resolution Radiometer (AVHRR) - derived seasonal trends of surface albedo, skin temperature and cloud changes are presented. Changes in the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) and related climate responses are shown. Finally, Arctic Climate Impact Assessment (ACIA) model projections of climate and sea ice for the late 21st century are presented. .Serreze, M.C. and Barry, R.G. 2005. The Arctic Climate System, Cambridge Univ Press. (Chapters 10 and 11). ATLANTIC WATER IN THE ARCTIC OCEAN: INFLOW, CIRCULATION AND VARIABILITY G.V.Alekseev, Arctic and Antarctic Research Institute, St.Petersburg, Russia

Atlantic Water (AW) inflow into the Arctic is a necessary component in the formation of the global oceanic conveyer. This water from the North Atlantic is spread through the Nordic Seas and penetrates into the Arctic Basin where it occupies the upper layer at depths of 50 to 800 meters and joins the circulation system of water and ice. AW is the most important heat source for the sub-Atlantic sector of the Arctic and salt source for the arctic water, experiencing constant freshening. The presence of AW leads to mixing, including deep convection, formation of new water masses and increase of bio-productivity in the upper mixed layer of the Nordic Seas. Weak but constant heat flux from the AW into the upper layer of the Arctic Basin limits the winter growth of ice. In this connection the AW inflow is the most important climate forming process in the Arctic climate system, and changes in AW influence not only the Arctic climate, but climate beyond the limits of the Arctic.

132

SEA ICE EXTENT AND SURFACE AIR TEMPERATURE IN THE NORTHERN HEMISPHERE G.V.Alekseev, Arctic and Antarctic Research Institute, St.Petersburg, Russia

Sea ice cover of the polar oceans comprises the most important part of the earth’s cryosphere and influences climate change at a scale from several years to decades. As seen from the experiments with the global climate models the decrease in sea ice cover is hastened by anthropogenic climate warming. On the other hand, freshening of the upper ocean layer during climate warming is favorable for sea ice spread during winter, leading to a decrease of the warming effect of the ocean on the atmosphere. Such an uncertainty of interaction between climate change and sea ice extent must be reflected in the relationship between surface air temperature and ice extent; the leading role in this relationship is usually given to the air temperature. On the basis of the published literature (Alekseev et al., 2003; 2005) we consider the following points in our lecture:

• Variability of sea ice extent (SIE) of the entire Northern Hemisphere and within its separate regions according to observational data and modeling.

• Variability of the mean subsurface air temperature (SAT) according to the observational data and modeling data compared to the variability of SIE.

• How could the variability of SIE influence the average air temperature? • Season-dependent relations between SIE variations and SAT. • Connection between SAT and SIE variability, taking into account the delay time and

the season. • Discussion of the estimated regularities: mechanisms and back coupling problems.

POLAR AMPLIFICATION OF SURFACE TEMPERATURE CHANGE IN A WARMING CLIMATE Peter L. Langen, Niels Bohr Institute, University of Copenhagen, Denmark, Vladimir A.Alexeev, International Arctic Research Center, University of Alaska Fairbanks, USA

Most modeling studies show climate warming to be most pronounced at high latitudes. This effect is called polar amplification and is the focus of the thesis in which a general circulation model (GCM) of the atmosphere is employed in a series of simplified studies of the effect. In the presentation, polar amplification will be discussed chiefly in terms of the system's linearized dynamics. A method based on the fluctuation-dissipation theorem is used to extract the linear stability and sensitivity characteristics of the model climate and the polar amplification is seen to arise as an excitation of the slowest-decaying stable eigenmode. It is demonstrated that the polar amplified shape of this mode is due to a communication of tropical temperature perturbations to high latitudes through changes in the poleward energy transport. The details of these transport changes are found not to carry over to all climate states which differ from that of the present day, and regimes seem to exist where polar amplification does not occur. IMPACTS OF THE NORTH ATLANTIC OSCILLATION ON SCANDINAVIAN HYDROPOWER PRODUCTION AND ENERGY MARKETS JESSIE CHERRY1,∗, HEIDI CULLEN2, MARTIN VISBECK3, ARTHUR SMALL 4 and CINTIA UVO 5 1) Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, U.S.A.; 2) The Weather Channel and Georgia Institute of Technology, Atlanta, GA, U.S.A.; 3) Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, U.S.A.; 4) School of International and Public Affairs, Columbia University, New York, NY, U.S.A.; 5)Department of Water Resources Engineering, Lund University, Sweden

Dramatic swings in the North Atlantic Oscillation (NAO) during the 1990s motivated the authors to build a statistical model of NAO impacts on hydropower production and energy markets in Scandinavia. Variation in the NAO index is shown to explain 55% of the variance of streamflow in Norway and up to 30% of the variance in Norway’s hydropower output. It is also possible to identify the influence of NAO anomalies on electricity consumption and prices. Government liberalization allowed a financial market to grow around the international trading of

133

electricity, which in Norway is produced almost entirely from hydropower. The model offers a possible tool for predicting the effects of future NAO movements on hydropower production and energy prices in Scandinavia. The potential influence of skillful climate prediction is discussed.

DEVELOPMENT OF A SNOW WATER EQUIVALENT (SWE) ALGORITHM OVER FIRST-YEAR SEA ICE USING PASSIVE AND ACTIVE MICROWAVE RADIOMETRY Alexandre Langlois and David G. Barber, University of Winnipeg, Manitoba, Canada

Snow cover over first-year sea ice is a key parameter in the energy and mass transfer across the ocean-sea ice-atmosphere (OSA) interface (Arons and Colbeck, 1995). Snow regulates heat transfer between the atmosphere and ocean due to its low thermal conductivity (Sturm et al., 2002), playing a dominant role in the surface energy balance (Moritz and Perovich, 1996; Sturm at al., 2002). Snow also controls the amount of solar energy absorbed into the snow/sea ice system; energy absorption is largely affected by snow physical properties such as SWE, temperature and brine volume (e.g., Barber and Thomas, 1998; Warren, 1999; Zhou and Li, 2002). As a result, slight changes in snow thermo-physical properties during winter will greatly alter surface radiation and energy balance (e.g. Welch and Bergmann, 1989; Barber et al. 1998; Mundy et al., 2005) as well as the timing of annual freezing/melting of sea ice (Ledley, 1991; Flato and Brown, 1996; Boer et al., 2000).

Electromagnetic interactions over a broad spectrum such as passive microwave have proved to be a useful tool to monitor snow due to its cloud transparency and independence of daylight (e.g. Ulaby et al., 1986; Barber et al., 1998; Golden et al., 1998). Passive microwave brightness temperature (Tb) is closely linked to the dielectric properties of the snow cover, which are in turn related to snow physical properties such as SWE. Changes in snow microstructure resulting from metamorphic processes will considerably change the microwave emission, especially at higher frequencies such as 37 and 85 GHz (e.g. Armstrong et al., 1993; Lohanick, 1993). Water volume in liquid phase also reduces SWE estimation accuracy due to its significant contribution to passive microwave emission (Drobot and Barber, 1998).

Therefore, the main objective of this research is to better understand the empirical and physical relationships between snow thermophysical properties such as SWE and their impact on the microwave measurements from scattering and dielectric perspectives. These relationships will help us build a physically-based algorithm to remotely retrieve SWE coupling, including both active and passive microwave data, from space-borne remote sensing. Such an algorithm will be an excellent tool for the development and validation of geophysical and thermodynamic models, improving the accuracy of these models as they explore the various proposed climate change scenarios. IMPACT OF INVERTEBRATE PREDATORS ON THE ZOOPLANKTON COMMUNITY IN THE BORNHOLM BASIN (CENTRAL BALTIC)Kristina Barz, Alfred-Wegener-Institute for Polar and Marine, Bremerhaven, Germany

Scyphomedusae are conspicuous members of marine pelagic ecosystems. When they reach high abundance, they can reduce the stocks of zooplankton communities considerably (e.g. Matsakis and Conover 1991; Purcell 1992; Olesen 1995; Omori et al. 1995; Lucas et al. 1997; Schneider and Behrends 1998). The most important effects of predation by medusae are summarized by Purcell (1997): Top down control of zooplankton populations and competition with fish for food, consumption of fish eggs and larvae, and changes in the zooplankton community through predation on organisms at various trophic levels.

In Kiel Bight (western Baltic Sea) Aurelia aurita sometimes reaches high densities. In such “bloom” years a reduction in the copepod and herring (Clupea harengus) larvae populations was observed there (Möller 1980; Schneider and Behrends 1998).

During an intensive field study in the Bornholm Basin in the framework of German Global Ocean Ecosystem Dynamics (GLOBEC), which focuses on the interactions between zooplankton and fish under the influence of physical processes, it was our aim to assess the role of scyphozoan medusae in the pelagic food web. As they are the only invertebrate predators amongst the plankton besides chaetognaths and mysids, they may constitute an important factor controlling zooplankton mortality. In addition medusae compete for zooplankton with the commercially important planktivorous fish species sprat (Sprattus sprattus) and herring, but also may prey on fish eggs and larvae and thus directly affect their recruitment.

134

In order to answer these questions, seasonal and vertical distribution of the two scyphomedusae in the Bornholm Basin were described and their abundance estimated. From gut content analysis of A. aurita predation rates were estimated and the impact on the zooplankton community was calculated.

A. aurita occurred from July to November with a maximum mean abundance of 2.3 ind. 100 m-3 in August, whereas C. capillata was caught in much smaller numbers from July to September. From July to October ~80 % of A. aurita medusae were distributed in the upper 20 m above the thermocline, whereas C. capillata occurred only in the halocline below 45 m. A. aurita did not migrate vertically and fed mainly on the most abundant cladoceran species Bosmina coregoni maritima. Further prey organisms were the cladocerans Evadne nordmanni and Podon spp., mollusc larvae and copepods. Copepod nauplii and copepodite stages I-III were not eaten by the medusae; in addition, fish eggs and larvae were not used as prey. Based on mean medusae and zooplankton abundance from the upper 20 m, the predatory impact was very low. In August, when mean abundance of A. aurita was highest, only 0.1 % of the copepod and 0.5 % of the cladoceran standing stock were eaten per day.

In conclusion we suggest that predation by A. aurita did not regulate the zooplankton community in the Bornholm Basin during this investigation. Although both A. aurita and sprat larvae fed on cladocerans, C IV-VI fish larvae should not suffer from competition with A. aurita. Limited spatial and seasonal overlap of fish eggs and larvae with medusae prevent them from being used as prey. ECOLOGY AND CONSERVATION OF EASTERN ARCTIC SHOREBIRDS Paul Smith, National Wildlife Research Institute, Carleton University, Ontario, Canada

Growing evidence suggests that shorebirds are declining throughout North America, but the cause is unclear. In this general overview of the status and conservation of arctic shorebirds, I explore the possible causes of decline, highlight monitoring and outreach programs and discuss my current research on the breeding ecology of arctic shorebirds.

From 2000-2005, I studied a community of 5 shorebirds at East Bay, Southampton Island, Nunavut. I examined the link between nest success and factors such as nest habitat, dispersion and the distribution of food resources. I found strong patterns of non-random nest placement and clear evidence of habitat preferences. However, I found little evidence that variation in nest habitat was related to variation in success within or between species. Shorebirds did not prefer to nest in habitats where food was most abundant. Nest success was not consistently higher in preferred habitats. Instead, reproductive success may be related to more subtle factors such as parental behaviour, protective nesting associations or annual weather patterns.

I demonstrate the direct influence of climate on shorebird reproduction through its effects on timing of breeding. I discuss the importance of indirect effects of climate on shorebird populations, through its effects on cyclic predation pressure. The cause of nearly all shorebird nest failure is predation, and the primary factor dictating the rate of nest loss is the climate mediated cycle of arctic foxes and lemmings. This concept is discussed in the context of current monitoring programs. SALINITY VARIATIONS IN SEA ICE Martin Vancoppenolle, Institut d'Astronomie et de Géophysique G. Lemaître, Université Catholique de Louvain, Louvain-la-Neuve, Belgium

A one dimensional halothermodynamic sea-ice model, created by coupling an energy-conserving thermodynamic model and a prognostic salinity model, is presented and validated against observations in Arctic conditions. The thermodynamic sea-ice model considers thermal properties and depends on salinity and temperature in order to take into account the thermal damping effect of brine pockets on heat transfer and storage in the ice, and on ice melting. The semi-empirical prognostic salinity model simulates the salinity profile in 20 layers of sea-ice. It includes as trend terms for salinity, the classical parameterizations of salt entrapment during growth, brine expulsion and gravity drainage. A new parameterization of the summer flushing

135

process, based on brine drainage transport under the influence of available surface meltwater, is proposed. Flushing is assumed to occur in summer, when in every layer the relative brine volume is above 5%. The model is tested with atmospheric and oceanic forcing coming from two regions of the Arctic (Point Barrow and the central Arctic). The two regions respectively correspond to First Year (FY) and Multi Year (MY) ice types. Salinity bulk values and profiles are compared with available observations, and impact on the thermodynamic characteristics of the ice is assessed. Sensitivity studies are conducted. Conclusions lead to the formulation of a simpler model giving bulk salinity in terms of ice growth rate and surface temperature, assuming a vertically constant salinity for FY ice and a linear profile of salinity for MY ice. ANTARCTIC ACCUMULATION FROM A PASSIVE MICROWAVE MODEL Lora S. Koenig1, Eric J. Steig1, Dale P. Winebrenner2 1) Department of Earth and Space Sciences, University of Washington 2)Applied Physics Laboratory, University of Washington

Climatic uncertainties in accumulation rates on ice sheets motivate us to develop remote sensing methods to measure this parameter. Passive microwave sensors offer a potential tool for retrieving both accumulation rates and temperature over the Greenland and Antarctic ice sheets. However, no accumulation retrieval method developed has been reliable in both temporal and spatial domains. Presented is a new retrieval method that shows considerable promise. The extinction-diffusion time (tau) is the ratio of the firn’s thermal diffusivity and the microwave extinction length squared. The extinction- diffusion characteristic time scale arises in a convolution expression that relates physical temperature to microwave brightness temperature, replacing the more traditional emissivity in the Rayleigh-Jeans approximation. Tau is estimated by comparing thermal infrared observations of physical surface temperature from the Advanced Very High Resolution Radiometer (AVHRR) satellite with passive microwave brightness temperatures at the 37 GHz vertically polarized channel measured by the Scanning Multichannel Microwave Radiometer (SMMR) and Special Senor Microwave Imager (SSM/I).

Comparison between tau and independent estimates of accumulation rate from radar-echo-sounding and shallow ice core observations near Byrd Station Antarctica shows a strong linear relationship for accumulation rates over a broad range -- from 10 to 50 cm/year ice equivalent. Averaged over the 18 years of available data, tau varies over this area from a few days to more than three months. Estimates of tau over short time intervals of three years show patterns reminiscent of expected accumulation rate variability, which are of the correct magnitude of expected patterns of temporal accumulation rate. Future research will focus on in-situ measurements of firn thermal diffusivity and microwave extinction lengths to compare with the model. THE ROLE OF PERMAFROST IN A CHANGING LENA RIVER BASIN AND IMPLICATIONS FOR FUTURE HYDROCLIMATOLOGY J. Cherry, LDEO, Columbia University, New York, NY USA V. Alexeev, IARC, University of Alaska Fairbanks, AK USA P. Groisman, NCDC, Ashville, NC, USA V. Romanovsky, GI, University of Alaska Fairbanks, AK USA M. Stieglitz, Georgia Tech, GA USA

Lena River basin station data show a number of trends over the past 60 years. Spring and winter have warmed, summer and autumn have cooled, and more precipitation falls in winter, spring, and autumn. Runoff trends include a modest increase in total runoff and a larger increase in runoff minimum, attributed to a baseflow which is larger in volume and sustained for a longer period. The proposed mechanism for increased baseflow is melting permafrost which increases soil porosity. A consequence of changes in subsurface storage could be changes in evapotranspiration at the surface. This idea is tested with the NASA Seasonal-to-Interannual Prediction Project Catchment-based Land Surface Model (CLSM). Simplified meteorological forcing is used to show that changes in soil porosity lead to changes in runoff partitioning between surface and baseflow. In CLSM, increased soil porosity leads to decreased surface runoff, increased baseflow, a delay in total runoff maximum and minimum, a similar delay in evapotranspiration (ET) maximum and a slower decay in ET following a seasonal cessation of

136

precipitation. These results are consistent with observations, though differences between simplified and realistic meteorological forcing are discussed. THE ARCTIC ATMOSPHERE Peter J Minnett, University of Miami

The Arctic atmosphere is an important component of the global ocean-atmosphere system. The polar regions serve as the heat sink of the global climate system; the earth loses heat to space through the polar atmosphere. Despite its obvious importance the conditions of the Arctic atmosphere are poorly understood. This is a consequence of the difficulty of making measurements in a harsh environment, and the fact that many processes, such as interactions with the surface, take place on scales not resolved by weather and climate models. Furthermore the polar regions present specific difficulties for the remote sensing of atmospheric properties from satellites. The presentation will place the Arctic atmosphere within the global perspective and describe some of the instruments used to obtain the basic meteorological parameters in the Arctic. The propagation of visible and infrared radiation through the Arctic atmosphere will be discussed in some detail, and the present state of our knowledge of Arctic cloud cover will be presented. Emphasis will be placed on measurements taken from research icebreakers and comparisons made with data taken from coastal stations, satellite retrievals, and numerical forecast models and reanalyses. REMOTE SENSING OF THE ATMOSPHERE AND SURFACE Peter J Minnett, University of Miami

Satellite remote sensing offers a powerful tool for gathering information about the Arctic surface and overlying atmosphere. However, such measurements do not provide the answers to all questions. The presentation will consist of an overview of satellite remote sensing techniques, spanning active and passive sensors in the visible, infrared and microwave parts of the electromagnetic spectrum. The advantages and limitations of each type of sensor will be discussed with specific examples drawn from the Arctic. SURFACE HEAT BUDGET OVER LEADS AND POLYNYAS Peter J Minnett, University of Miami

The open water in the midst of the Arctic sea ice, leads and polynyas, are important sites of surface and atmosphere coupling and enhanced exchanges of heat, moisture and other gases. As elsewhere in the global oceans, the components of the surface heat budget of leads and polynyas in the Arctic comprise radiative and turbulent terms. The radiative are split into shortwave (originating at the sun) and longwave (infrared emission) terms; the turbulent fluxes are the sensible heat flux and the latent heat flux, which results from evaporation from the ocean surface. The characteristics and relative magnitudes of each term will be discussed. New measurement techniques involving infrared interferometry from ships will be presented. The dominance of the radiative terms in the summertime surface heat budget gives rise to the possibility of a range of feedback mechanisms that can enhance or diminish surface heating though radiative interactions with clouds and aerosols. These feedbacks can lead to accelerated or retarded rates of ice melting in a changing climate. The presentation will also include a discussion of how leads and polynyas influence the atmosphere above and downwind of the open water. THE ARCTIC ATMOSPHERIC BOUNDARY LAYER AND CLIMATE Thorsten Mauritsen, Stockholm University, Sweden.

Recent observations of rapid climate change in the Arctic, as described in the latest Arctic Climate Impact Assessment report, point towards the need for a better understanding of the Arctic boundary layer processes. It is demonstrated that the summertime Arctic boundary layer is very different from its midlatitude counterpart. It is usually shallow, a few hundred meters or less, cloudy and highly variable.

The large-scale flow of the atmosphere transports heat and moisture from the low latitudes to the Arctic. The boundary layer is cold, and therefore dense, forcing the warm air to ascend

137

above it into the free atmosphere as it moves northward. This process leads to strong stratification in the upper part of the boundary layer. Heat is then transported towards the surface by radiative and turbulent processes.

It is shown that present-day operational and climate models describe the effects of turbulence poorly under stratified conditions. With no exception the models in the comparison were too diffusive, leading to exaggerated downward turbulent heat flux in the Arctic. We have developed a new turbulence closure model, which handles the stratified conditions which prevail in the Arctic. We intend to investigate the climate system effects of these deficiencies in the near future. STABLE CARBON ISOTOPE RATIOS OF NONMETHANE HYDROCARBONS IN THE ARCTIC ATMOSPHERE Alex Thompson, University of California Berkley, CA USA

The stable carbon isotope ratio (13C/12C, or δ13C value) of nonmethane hydrocarbons (NMHCs) is shown to be a powerful new way to illuminate and quantify atmospheric processes. δ13C values can be used to quantify the extent of photochemical processing a compound has undergone since emission to the atmosphere. This allows us to characterize sources impacting a given site, to probe atmospheric mixing and transport, and to identify and quantify the impact of chemical reactions on atmospheric NMHC.

Compound specific δ13C values of NMHC and several halocarbons were measured in emissions to the atmosphere, and in the Arctic troposphere. For the first time the seasonal variation of isotope ratios of selected NMHCs was determined. Outlier δ13C values observed for springtime ethane in the Arctic are compatible with Cl atom chemistry associated with tropospheric ozone depletion. Measurements of the δ13C of tropospheric ambient chloromethane allow additional constraints to be placed on the atmospheric budget of chloromethane.

In addition, a three-dimensional global chemical tracer model of the atmosphere was adapted to predict the temporal and spatial variation of the stable carbon isotope ratio of NMHCs and chloromethane. δ13C predictions allow the identification of two distinct seasonal regimes in the model, most visible at high latitudes and in locations remote from sources. From spring into summer the polar air mass behaves as an isolated system undergoing photochemical processing. In fall, model predictions can be described by relatively recent emissions progressively mixing with the summertime air mass.

To make the measurements, the analytical method (gas chromatography isotope ratio mass spectrometry, GC-IRMS) was extended to allow for the isotopic analysis of C2-C10 hydrocarbons and chloromethane in a single analysis at concentrations typically found in remote air masses, a result that had previously not been achieved. MICROBIAL ACTIVITY IN THE ARCTIC OCEAN Sharon Hoffman, MIT, MA USA

Microbes are by far the most abundant form of life on the planet, thriving under the most extreme conditions imaginable. Many of these extreme conditions occur in the oceans, making such microbes of interest to marine biologists and oceanographers. How do these organisms survive? Microbes are also important to study because of their ecological significance: they are responsible for rapid cycling of nutrients in the upper water column, and provide a link between dissolved and particulate nutrients and higher trophic levels such as zooplankton and fish. Arctic microbial communities are attracting attention now, for their hitherto unsuspected richness and their role in a delicate and changing ecosystem.

Marine microbes produce different types of enzymes to take advantage of the many food sources in the water. In this project, we analyze enzyme activities from four sources: Arctic cod, copepods, snails, and filtered particulate matter. By investigating the activities of different enzymes, at different temperatures, on each of these sample types, we hope to gain insights into the nature of microbial communities in different microenvironments in the Arctic. We find different enzymatic emphases in samples from host organisms, where activity of chitin-decomposing enzymes far outstrips that of the protein-decomposing protease, and in samples from sinking particulate matter filtered from the water column, in which protease is the more

138

dominant enzyme, providing nitrogen-rich nutrients for the bacteria attached to microaggregates. Enzymatic response to changes in temperature also appears to vary between sample type; while many of the assays show evidence of adaptation to the cold environment, some enzymes tested here may operate less effectively at cold temperatures. These findings, although preliminary in the extreme, offer a tantalizing glimpse of the diversity of Arctic microbial behaviour.