Assessing Climate Change in Antarctica Through ITASE

In 1990 a meeting held in Grenoble, France, brought many of the investigators involved in national ice coring efforts together to report on planned activities and discuss areas of potential international cooperation. One of the major products of the Grenoble meeting was the interest generated in a plan to study the surface and near-surface record of several ice core parameters (e.g., accumulation rate, stable isotopes, chemistry) over the major topographic and climatic regions of Antarctica. This plan was soon formulated into a program, called the International Trans Antarctic Scientific Expedition (ITASE), which, based on the scientific representation at that meeting, included: Australia, Canada, China, France, Italy, Germany, Japan, Russia, Sweden, Switzerland, the United Kingdom and the United States. Scientists from several other countries have since demonstrated an interest in the program. It was agreed that a knowledge of the distribution of Antarctica's major environmental parameters (e.g., climate, atmospheric chemistry), as measured through ice cores, would result in major contributions to the understanding of global change and Antarctica's sensitive environment and advance the interpretative capabilities required to compare existing and proposed ice coring programs.

A concept for the preliminary implementation of ITASE (ITASE, 1992), including proposed national components, was formally recommended to XXII SCAR (Scientific Committee for Antarctic Research) at the 1992 meeting in Bariloche, Argentina, by the Working Group on Glaciology. At this meeting the SCAR delegates approved ITASE as Recommendation Glaciology XXII-5. Further it was clearly established at this time that ITASE could make notable contributions to the six main SCAR initiatives dealing with the crucial role Antarctica plays in global change. ITASE was subsequently formally accepted under one of SCAR's primary initiatives, GLOCHANT (Global Change in Antarctica) during the XXIII SCAR Meeting in Cambridge, England.

ITASE was formally adopted as an IGBP (International Geosphere-Biosphere Program) PAGES (Past Global Changes) Project in 1993 under PAGES Focus II.

The broad aim of ITASE is to establish how the recent atmospheric environment (climate and atmospheric composition) is represented in the upper layers of the Antarctic ice sheet. Primary emphasis is placed on the last ~200 years of the record. This time period was chosen because it covers the onset of major anthropogenic involvement in the atmosphere and the end of the Little Ice Age. The shallow depth of the cores required to span 200 years of record will make a spatially significant study a relatively simple task. Specific ITASE objectives are:

(1) To determine the spatial variability of climate (e.g., accumulation, air temperature, atmospheric circulation) over the last 200 years.

These variations include:

The resultant extended climatic depiction for the major global atmospheric heat sink will be unrivalled for 10% of the earth¼s land surface.

(2) To determine the environmental variability in Antarctica over the last 200 years.

Because of the remoteness of the continent, Antarctica is an ideal location to monitor biogeochemical cycles and global scale changes such as sea ice variation, ocean productivity, anthropogenic impacts and other, extra-Antarctic continental influences.

In fulfilling these objectives ITASE will:

Since the 1991 SCAR meeting, progress has been made toward implementing ITASE, although the primary energy of the international ice coring community has been directed toward deep drilling at the Summit site in Greenland and various deep drilling activities in Antarctica. Since the successful completion of deep drilling in Greenland, the international ice coring community has begun to focus even more attention toward activities in Antarctica. At the same time several other major scientific efforts in, for example, paleoclimate research, glaciology, geophysics, atmospheric chemistry, and meteorology have defined scientific objectives that could be served by ITASE.