Mass balance of the Antarctic ice cap

This study makes part of the EPICA project (European Project for Ice Coring in
Antarctica) which falls under the international research effort developed
during the last decades in order to try to put forward a scientific response to
the problems of the global climatic changes.

The two large polar ice caps of Greenland and the Antarctic are privileged
actors of the global climate system. Not only their high capability to reflect
the solar radiation influences the balance of the energy reaching the surface
of the Earth, but they can contribute, by their possible melting, to the rise
of the average sea level. These polar ice caps also constitute a record of the
climatic system insofar as they register and preserve within their ices the
past climatic variations.

The project intends to contribute to tasks specifically identified in the EPICA
scientific plan. It relates primarily to the development of a climatology
(characteristics of the climate, here the current climate) of the Atlantic and
Indian sectors of Antarctica established on the basis of the application of a
regional climatic model (RCM). This climatology is expected to bring new
elements in the knowledge of the spatial distribution of the climatic
parameters specific to the above-mentioned areas, and to contribute thus to the
process of interpretation of the palaeoenvironmental signals extracted from
EPICA ice cores. It has as an additional aim to develop a function "surface
mass balance" which will be made available to glaciologists modellers
participating in EPICA research-work.

GOALS

The global objective of EPICA is to carry out a continuous and high resolution
reconstruction of the global climate and past environmental changes, from the
scale of the century to the scale of several hundreds of thousands of years, on
the grounds of the analysis of ice cores sampled by deep drilling.

Two great stages of drilling are envisaged. The first, currently ongoing,
relates to the central part of the Antarctic cap, namely the zone of Dome
Concorde. The second targets the Atlantic sector of the cap, namely the Queen
Maud Land. The final site will be selected according to the results obtained at
Dome Concorde.

The objectives of this research are the following :

A) To establish a relation between the global climate and the local climate
specific to the sites of EPICA drilling, relation which could be reversed
during the reconstruction of the global climate based upon the analysis of ice
cores. In a more specific way, the research will tackle to such an aim:
- the identification of the relevant features (high rate of accumulation,
significant climatic influence of the Atlantic Ocean) which will enable to
select the most appropriate site of drilling in Queen Maud Land;
- the correct interpretation of climatological parameters of the ice core from
Dome Concorde such as the delta18O and deltaD;
- the quantification of the movements of the ice which are to be taken into
account to correctly interpret the age of the ice core from Dome Concorde.

B) To provide the EPICA scientific community with a function of "weight
breakdown of surface" of the Antarctic ice cap which should allow to reduce the
uncertainty which still remains on the contribution of this cap to a possible
elevation of the average level of the seas during the next century.