A Decade of Frontier Oceanography Achievements during WAIS.
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A Decade of Frontier Oceanography Achievements during WAIS
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Transcript of A Decade of Frontier Oceanography Achievements during WAIS.
A Decade of Frontier
OceanographyAchievements during WAIS
Courant Institute of Mathematical Sciences
New York UniversityNew York, U.S.A.
David Holland Adrian Jenkins British Antarctic SurveyNatural Environment Research CouncilCambridge, U.K.
Notable Ice Shelves of West Antarctica
PIG
FRIS
RIS
Main Seas Bordering West Antarctica
WEDDELL
BELLINGS-HAUSEN
AMUNDSEN
ROSS
Observational Advances
O.1 Ice-Shelf-Front HydrographyO.2 Hot-Water DrillingO.3 Radio-Echo SoundingO.4 Phase-Sensitive RadarO.5 Topographic SoundingsO.6 Autonomous Underwater Vehicles
Numerical Modeling
M.1 Z-levelM.2 Terrain-FollowingM.3 Isopycnic-CoordinateM.4 ISOMIP
Outline
Ice-Front Cruises
Ice-Front Moorings
Autonomous vehicles
Observational Techniques
Radio Echo Soundingvia airplane
Phase-Sensitive Radar
Hot-Water Drilling
Topographic Soundings
O.1 Ice-Shelf-Front Hydrography
O.1 Ice-Shelf-Front Hydrography
Foldvik et al., Antarct. Res. Ser., 1985
O.1 Ice-Shelf-Front Hydrography
O.1 Ice-Shelf-Front Hydrography
Sea Ice Pine Island Glacier
Polynya
Temperature Section
Temperature Section
Jacobs et al., Geophys. Res. Lett., 1996Jenkins et al., J. Glaciol., 1997Hellmer et al., Antarct. Res. Ser., 1998
Melting 12 tonnes of snow
Heaters and pumps
O.2 Hot-Water Drilling
Drill Stand
Courtesy of Keith Nicholls, B.A.S.
CT+CM
CT
CT
CT
CT+CM
T
T
T
T
T
T
T
TTT
T
T
T
Thermistorcable
Inductive loopfor CT and CM820 m
485 m
40 m
CM = current meter
T = thermistorCT = conductivity+temperature
O.2 Hot-Water Drilling
Courtesy of Keith Nicholls, B.A.S.
Ocean
Glacier
Bedrock
O.1 Hot-Water Drilling
O.2 Hot-Water Drilling
Courtesy of Keith Nicholls, B.A.S.
O.3 Radio-Echo Sounding
O.3 Radio-Echo Sounding
Thyssen et al., Polarforschung , 1993
Flight Tracks
O.3 Radio-Echo Sounding
Marine-Only Ice
Thickness
Marine-Ice Thickness: … 300 m
(> 50 % of total thickness)
Thyssen et al., Polarforschung , 1993
O.4 Phase-Sensitive Radar
Courtesy of Craig Stewart, B.A.S.
O.4 Phase-Sensitive Radar
O.4 Phase-Sensitive Radar
O.4 Phase-Sensitive Radar
Jenkins et al., FRISP Report 14, 2003
380 382 384 386 388 390 392 394 396-0.02
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
Day number
Thi
ckn
ess
chan
ge (
m)
BEDMAP Bedrock
Depth
Bedmap Web Pages, 2001
O.5 Topographic Soundings
BEDMAP Ice
Thickness
Bedmap Web Pages, 2001
O.5 Topographic Soundings
O.6 Autonomous Underwater Vehicles
Courtesy of Nick Millard, S.O.C.
M.1 Z-Level
M.1 Z-Level
Grosfeld et al., 2001
M.2 Terrain-Following
Hellmer, GRL, 2004
M.3 Isopycnic-Coordinate
M.3 Isopycnic-Coordinate
M.3 Isopycnic-Coordinate
Flow Schema
M.3 Isopycnic-Coordinate
2-Year Simulation: MICOM
M.3 Isopycnic-Coordinates
Standard Experiment
- Protocol
M.4 ISOMIP
Participating Models
M.4 ISOMIP
• Sub-ice-shelf cavities are probably the least accessible regions of the world ocean.
Conclusions
• They influence both the ice sheets and the deep ocean.
• Models provide much insight, but there is some disagreement between them.
• New observations and model intercomparison provide real hope of resolving these problems.
