Model estimates of Antarctic accumulation rates and their relationship to temperature changes

Abstract

The results from long-term simulations with a climate model using historical sea surface temperatures (SSTs) are used to study Antarctic accumulation rates and their relationship, or sensitivity, to temperature changes. The model used has a horizontal resolution of approximately 2°by 2°. The SST data comprise reconstructed monthly values on a global grid for the period 1950-91. The results yield an estimate for the area-averaged value accumulation rate over grounded ice of 160-180 mm w.e. a-1. The spatial pattern of the simulated trends over the period of integration indicates that the results for much of East Antarctica are consistent with evidence deduced from ice cores. The ice-sheet surface is estimated to have warmed by +0.73°C (a rate of +0.18°C per decade), while the accumulation rate is estimated to have increased by +7.7 mm a-1 (a rate of +1.9 mm a-1 per decade). The estimate for sensitivity is +12.5 mm a-1 per degree of warming, which can be interpreted as about -0.4 mm of sea level per year.