ANTCI Overall ObjectiveANTCI Overall Objective

To provide a more comprehensive To provide a more comprehensive understanding of Antarctic atmospheric understanding of Antarctic atmospheric chemistry with the goal of providing chemistry with the goal of providing new insights related to the new insights related to the interpretation of the levels and interpretation of the levels and distributions of C, S, and N climate distributions of C, S, and N climate proxy species contained within ice cores proxy species contained within ice cores

Specific Scientific Specific Scientific Objectives:Objectives:

• Evaluate the detailed chemical and dynamical Evaluate the detailed chemical and dynamical processes that control spring/summertime levels processes that control spring/summertime levels of NOof NOxx/NO/NOyy and OH/HO and OH/HOxx at South Pole. at South Pole.

• Assess the representativeness of South Pole fast Assess the representativeness of South Pole fast photochemistry, as driven by photodenitrification photochemistry, as driven by photodenitrification of snow, to the larger polar plateau regionof snow, to the larger polar plateau region

• Investigate the relative importance of the Investigate the relative importance of the oxidative processes involved in the coast-to-oxidative processes involved in the coast-to-plateau transport of reduced sulfur and plateau transport of reduced sulfur and determing the principal regions of chemical determing the principal regions of chemical transition.transition.

Secondary ObjectivesSecondary Objectives::• Investigate snow/firn chemical species Investigate snow/firn chemical species

that undergo extensive exchange with that undergo extensive exchange with the atmosphere (e.g., NOthe atmosphere (e.g., NOxx, HNO, HNO33, CH, CH22O, O, HH22OO22, monocarboxylic acids)., monocarboxylic acids).

• Assess the different chemical forms of Assess the different chemical forms of the trace element Hg and their the trace element Hg and their relationship to the levels of Orelationship to the levels of O33, OH and , OH and other potential oxidants.other potential oxidants.

Questions Which RemainQuestions Which Remain● ● Why does NOx increase at SP when the wind is Why does NOx increase at SP when the wind is

from the east?from the east?● ● How does a shift away from a 24 hr constant sun How does a shift away from a 24 hr constant sun

light environment affect the emission rate of NOx light environment affect the emission rate of NOx on the plateau?on the plateau?

● ● How does NOHow does NOxx decrease as it flows toward the decrease as it flows toward the coast? Upward Mixing, Diurnal Cycling, Surface coast? Upward Mixing, Diurnal Cycling, Surface Chemistry, Other?Chemistry, Other?

● ● Where does the reactive nitrogen observed at the Where does the reactive nitrogen observed at the Pole come from? Stratosphere, Lightening in the Pole come from? Stratosphere, Lightening in the Southern Oceans?Southern Oceans?

●● How do oxidation rates [OH] change with altitude How do oxidation rates [OH] change with altitude and geographical location over the plateau, i.e. and geographical location over the plateau, i.e. what is the range of the OH oxidizing canopy?what is the range of the OH oxidizing canopy?

● ● Where is the MS/SOWhere is the MS/SO44= = ratio determined? Near the ratio determined? Near the

coast at higher altitudes or gradually as sulfur is coast at higher altitudes or gradually as sulfur is transported inland, i.e. why is this ratio typically transported inland, i.e. why is this ratio typically 0.07 over most of the plateau?0.07 over most of the plateau?

●Are NO, NO2, CH2O, H2O2 and other compounds

emitted from the snow surface over the whole plateau region? Near the coast? ●How much of the nitrogen formed over the continent flows out of glacial valleys to the sea

General Questions: ●What can we learn about transport from reactive and passive chemical tracers?●How much is the MS/SO4

= ratio effected by deposition location as opposed to sulfur sources or temperature?

ANTCI 2005 Flight Missions and Constrains

We have 1 Otter from ~Nov. 14 – Dec. 17

Missions:We have proposed ~ 14 flights out of McMurdo & 4 out of the South Pole (7 days at the South Pole - 2 flights to Weddell Sea, 1 to Max alt., & 1 return to McMurdo)

Constrains:Fuel along Ross coast, low latitude, and maybe for Weddell Sea

Boundary Layer

Inflow

ANTCI 2005

CompoundCompound InvestigatoInvestigatorr

TechniqueTechnique SensitivitySensitivity

HNO3HNO3 HueyHuey SICIMSSICIMS 5 pptv5 pptv

HO2NO2HO2NO2 HueyHuey SICIMSSICIMS 5 pptv5 pptv

SO2SO2 HueyHuey SICIMSSICIMS 5 pptv5 pptv

Aerosol SO4,MS, Aerosol SO4,MS, NO3?NO3?

Huey WeberHuey Weber PILS-IC /CNNPILS-IC /CNN 1 pptv ?1 pptv ?

OHOH Eisele/Eisele/MauldinMauldin

SICIMSSICIMS 1x101x1055 mol/cmmol/cm33

HO2/RO2HO2/RO2 Eisele/Eisele/MauldinMauldin

SICIMSSICIMS 5x105x105 5

mol/cmmol/cm33

H2SO4H2SO4 Eisele/Eisele/MauldinMauldin

SICIMSSICIMS 1x101x105 5

mol/cmmol/cm33

MSAMSA Eisele/Eisele/MauldinMauldin

SICIMSSICIMS 1x101x105 5

mol/cmmol/cm33

NONO Buhr/DavisBuhr/Davis ChemiluminesceChemiluminescencence

5 pptv5 pptv

NONOyyBuhr/DavisBuhr/Davis ChemiluminesceChemiluminesce

ncence10 pptv10 pptv

DMSDMS BlakeBlake Grab sample Grab sample GC/MSGC/MS

1 pptv1 pptv

NMHC& HCNMHC& HC BlakeBlake Grab sample Grab sample GC/MSGC/MS

0.1-1 pptv0.1-1 pptv

Actinic fluxActinic flux Shetter/Shetter/LeferLefer

SpectroradiometSpectroradiometerer

N/AN/A

Twin Otter Measurements

Flight Location Description Flight Time

McM-McM South along Ross Sea coast & up Byrd Glacier & return (refuel if possible)

6 if possible

McM-McM South along Ross Sea coast & up Byrd Glacier & return (refuel if possible)

4

McM-McM NO loss, flight to 75 S/150 E (or further Northeast, refuel if possible) 6 if at all possible

McM-McM South along Ross Sea coast & up Byrd Glacier & return (refuel if possible)

6 if possible

McM-Vostok-McM Outflow & sulfur sub. (refuel at TAMSEIS 11

McM-McM Ice shelf and ice edge survey 4

McM-McM Up coast to Terra Nova and return (refuel if possible) 6 if possible

McM-McM Ice shelf and ice edge survey 4

McM-McM Up coast to Terra Nova and return (refuel if possible) 6 if possible

McM-SP Plateau & outflow 3 refueling stop (Ref. J. English,Seismic,TAMSEIS,AGO4)

10

SP-Weddell Sea-SP In/out flow. Refueling stop on the way out and back at the same site 11

SP- 82 S/75 E -SP subsidence flight to about 82 S /75 E. Refueling stop on the way out & back at AGO4

11

SP-Weddell Sea-SP In/out flow. Refueling stop on the way out and back at the same site 11

SP-McM Low altitude outflow. 3 refueling stops (Ref. J. English,Seismic,TAMSEIS,AGO4)

10

McM-McM South along Ross Ice Shelf to Byrd Glacier and return 6

McM-McM Up coast to Terra Nova and return 4

McM-McM South along Ross Ice Shelf to Byrd Glacier and return 6

McM-McM Ice shelf and ice edge survey 4

Total The flight campaign will start and end at McMurdo 126

LC-130 Fuel Flight

LC-130 Airdrop fuel at AGO2/LaPaz Icefields 8