Accession Number : ADP007330

Title :   The Impact of Global Warming on the Antarctic Mass Balance and Global Sea Level,

Corporate Author : MELBOURNE UNIV PARKVILLE (AUSTRALIA)

Personal Author(s) : Budd, W. F. ; Simmonds, Ian

Report Date : MAR 1992

Pagination or Media Count : 6

Abstract : The onset of global warming from increasing greenhouse gases in the atmosphere can have a number of important different impacts on the Antarctic ice sheet. These include increasing basal melt of ice shelves, faster flow of the grounded ice, increased surface ablation in coastal regions, and increased precipitation over the interior. An analysis of these separate terms by ice sheet modeling indicates that the impact of increasing ice sheet flow rates on sea level does not become a dominant factor until 100--200 years after the realization of the warming. For the time period of the next 100 years the most important impact on sea level from the Antarctic mass balance can be expected to result from increasing precipitation minus evaporation balance over the grounded ice. The present Antarctic net accumulation and coastal ice flux each amount to about 2000 km3 yr-1, both of which on their own would equate to approximately 6 mm yr-1 of sea level change. The present rate of sea level rise of about 1.2 mm yr-1 is therefore equivalent to about 20% imbalance in the Antarctic mass fluxes. The magnitude of the changes to the Antarctic precipitation and evaporation have been studied by a series of General Circulation Model experiments, using a model which gives a reasonable simulation of the present Antarctic climate, including precipitation and evaporation.

Descriptors :   *BALANCE, *ICE, *IMPACT, *MASS, *SEA LEVEL, *SHEETS, *ANTARCTIC REGIONS, ABLATION, ACCUMULATION, ATMOSPHERES, CIRCULATION, CLIMATE, COASTAL REGIONS, EVAPORATION, FLOW, FLOW RATE, GLOBAL, MELTS, MODELS, NETS, NUMBERS, OCEANS, PRECIPITATION, RATES, REGIONS, SIMULATION, SURFACES, TIME, SYMPOSIA.

Subject Categories : Geography
      Meteorology
      Snow, Ice and Permafrost

Distribution Statement : APPROVED FOR PUBLIC RELEASE