2002-2003 Science Planning Summary

Glaciology

Dr. Julie Palais
Program Manager

IU-323-O

NSF/OPP 00-87776
Station: McMurdo Station
RPSC POC: Kirk Salveson
Research Site(s): Traverse from Byrd Surface Camp to South Pole

U.S. ITASE: Deposition of the HFC degradation product trifluoroacetate in antarctic snow and ice
Dr. Joseph R. McConnell
Desert Research Institute
Division of Hydrologic Sciences
jmcconn@dri.edu

Deploying Team Members: See U.S. ITASE Management (IU-153-A)
Research Objectives: Pursuant to the 1987 Montreal Protocol and the 1995 Clean Air Act in the United States, the threat to global ozone posed by migration into the atmosphere of chlorofluorocarbons (CFC) has led to the release into the biosphere of some worrisome substitutes. One of these, trifluoroacetate (TFA), is a highly persistent, atmospheric degradation product of the halogenated ethane derivatives (HCFC, HFC).

As this class of chemicals is now in widespread industrial use, there is growing concern that TFA will accumulate in aquatic ecosystems. Extant data on the pre-industrial (background, or baseline) concentration of TFA in meteoric and surface waters, including antarctic ice, are ambiguous. Thus the impact of anthropogenic TFA on these background concentrations is hard to specify. Ice core records, however, can provide a useful proxy for background and thus enable models to be developed for anthropogenic TFA deposition.

Our primary objective is to use ice cores and snow pits at South Pole to develop a record of TFA deposition for the last millennium, focused especially on the past 20 years. This pre-industrial to present record of TFA in near-surface snow and ice at South Pole and in West Antarctica will be unique. It should elucidate the origin, transport, and fate of this contaminant over Antarctica and - possibly - the globe. More generally, it enhances the context for assessing potential impacts on antarctic ecosystems from the natural and anthropogenic sources, by providing vital data on the regional and long-range movement, and the eventual fate, of contaminants.


Field Season Overview:
The ITASE project team and support contractor staff traverse West Antarctica from Byrd Surface Camp (BSC) to South Pole Station. Two trains pulled by Challenger 55 Caterpillar tractors will transport personnel, instruments, and field camp equipment. Along the way, team members will collect ice cores and surface snow and ice samples, take meteorological readings, and collect radar profiles of the ice sheet. Periodically, Twin Otter aircraft will resupply the traverse team and transport samples back to Byrd Surface Camp. At the end of the traverse, the group will return to McMurdo Station where they will begin to analyze some of their samples. Other samples will be returned to their home institutions.