Measuring Antarctic Snowfall and it's Relationship to Synoptic Conditions

Antarctic snow accumulation is set to increase in a warming climate according to climate simulations, moderating the future contribution of the Antarctic ice sheet to sea-level rise. To accurately predict the future of the Antarctic ice sheets in a warming climate, models must accurately estimate snowfall and how it is changing over time. However, comparisons with satellite observations show that almost all CMIP5 climate models overestimated current snowfall, biasing surface mass balance estimates which in turn negatively influence climate projections. This study examines how data from the ERA5 reanalysis represents snowfall over the Ross Sea region and the relationship of this snowfall to extra-tropical cyclones.We also examine the long-term reanalyses record to identify whether changes in cyclone tracks and depth have impacted snowfall in this region. Satellite observations of snowfall derived from the combined CALIPSO CloudSat dataset are also used to examine how well ERA5 represents snowfall in this region in recent times. The underlying aim of the analysis being to complete a process-orientated analysis which can be used to test climate model performance. In addition, to satellite analyses we also use observations from a network of weather stations (SNOW WEB) distributed on the Ross Ice Shelf to examine the quality of ERA5 in the region.