From its original formulation in 1990, the International Trans Antarctic Scientific Expedition (ITASE) has had as its primary aim the collection and interpretation of a continental- wide array of environmental parameters assembled through the coordinated efforts of scientists from several nations. The primary planned product of this cooperative endeavor is the description and understanding of environmental change in Antarctica over the last ~200 years. As a demonstration of the importance of the original scientific objectives posed by ITASE, they were adopted as a key science initiative by both the International Geosphere-Biosphere Program (IGBP) and the Scientific Committee on Antarctic Research (SCAR).
In May 1996 a workshop sponsored by the National Science Foundation was held to develop a Science and Implementation Plan for the United States contribution to ITASE (called "US ITASE"). Because of the long-standing US research effort in West Antarctica, US ITASE chose to focus its activities in this region. At the US ITASE Workshop, participants developed a multi-disciplinary research plan that integrates meteorology, remote sensing, ice coring and surface glaciology, and geophysics through a four-phase approach. In Phase 1 meteorological modeling and remote sensing will be used to plan sampling strategies conducive to the major objectives of US ITASE. Phase 2 will involve ground-based sampling over four study areas (corridors). Although a broad spatial sampling of West Antarctica is proposed during Phase 2, it is expected that the logistic requirements for this sampling will be modest and highly efficient. Phase 3 allows for the continuation of ground-based sampling at a limited number of key sites where monitoring is required. Phase 4 is interpretation and modeling.
In its entirety, ITASE incorporates a wide range of general scientific objectives. Those which are specific to US ITASE address the following questions:
1. What is the current rate of change in mass balance over West Antarctica?
2. What is the influence of major atmospheric circulation systems (e.g., ENSO) and oceanic circulation on the moisture flux over West Antarctica?
3. How does climate (eg., temperature, accumulation rate, atmospheric circulation) vary over West Antarctica on seasonal, interannual, decadal and centennial scales, and what are the controls on this variability?
4. What is the frequency, magnitude and effect (local to global) of any extreme climate events recorded in West Antarctica?
5. What is the impact of anthropogenic activity (e.g., ozone depletion, pollutants) on the climate and atmospheric chemistry of West Antarctica?
6. How much has biogeochemical cycling of S, N and C, as recorded in West Antarctica, varied over the last 200+ years?
US ITASE provides an important spatial perspective for the shared research goals of a variety of research programs funded by the NSF, NASA and NOAA. Notably, questions 1-4 parallel closely themes identified by NSF's WAIS (West Antarctic Ice Sheet) intiative. It is expected that these overlaps of scientific purposes will make possible an efficient utilization of logistic resources in the execution of these linked research programs.
A series of specific US ITASE products is proposed for the tentatively scheduled 1997-2007 duration of this research effort. These products will provide direct benefit to national scientific efforts as noted as well as internationally based science programs developed through SCAR and IGBP. In order to further this goal, this report was presented to the international representatives attending the jointly sponsored GLOCHANT (SCAR) and PAGES (IGBP) ITASE Workshop in Cambridge, England in August 1996. It is expected that by the integration of US ITASE with the ITASE activities of other countries, major contributions will be made to our understanding of Antarctica's role in global change.