Circulation-induced changes in Antarctic precipitation in the 20th and 21st centuries based on IPCC model data

Scenarios from over ten global climate models and two re-analysis products (NCEP/NCAR and ERA-40) were utilized to study the atmospheric moisture budget over the Southern Ocean and Antarctica. Changes in the Antarctic moisture budget have a major impact on the Antarctic ice sheet mass balance and and hence will affect predictions of global sea level variations. The model simulations were implemented to support the Working Group 1 component of the IPCC's 4th Assessment Report. In this poster we relate components of the moisture budget, (e.g. moisture convergence, rate of change of precipitable water) to a classification of synoptic circulation patterns obtained using a neural network algorithm known as Self-Organizing Maps. Three decades (1991-2000, 2046-2055 and 2091-2100) were analyzed in order to (1) assess the quality of the model realizations in the 20th century, and (2) determine the range of predicted changes in the Antarctic moisture budget over the coming century.