Review of regional Antarctic snow accumulation over the past 1000 years

Here we review Antarctic snow accumulation variability, at the regional scale, over the past 1000 years. A total of 80 ice core snow accumulation records were gathered, as part of a community led project coordinated by the PAGES Antarctica 2k working group. The ice cores were assigned to seven geographical regions, separating the high accumulation coastal zones below 2000 m elevation from the dry central Antarctic Plateau. The regional composites of annual snow accumulation were evaluated against modelled surface mass balance (SMB) from RACMO2.4 and precipitation from ERA-interim reanalysis. With the exception of the Weddell Sea coast, the low-elevation composites capture the regional precipitation and SMB variability. The central Antarctic sites lack coherency and are either not representing regional precipitation or indicate the models inability to capture relevant precipitation processes in the cold, dry central plateau. The drivers of precipitation are reviewed for each region and the temporal variability and trends evaluated over the past 100, 200 and 1000 years. Our study suggests an overall increase in SMB across the grounded Antarctic ice sheet of ~ 44 GT since 1800 AD, with the largest (area-weighted) contribution from the Antarctic Peninsula (AP). Only four ice core records cover the full 1000 years and suggest a decrease in snow accumulation during this period. However, our study emphasizes the importance of low elevation coastal zones (especially AP and DML), which have been underrepresented in previous investigations of temporal snow accumulation.