Extending our knowledge of Antarctic SMB further back in time

The reconstruction of Antarctic surface mass balance (SMB) is essential for understanding ice sheet dynamics and sea level rise, yet existing datasets are limited to the satellite era (1979-present) because little is known about the sea surface conditions (SSCs) before 1979. Using a new SSCs product derived from a particle filtering reconstruction of the southern climate before 1979 to constrain the regional atmospheric model MAR, we expand the known SMB time series up to 1958. The dataset has been evaluated against AWS and SMB measurement campaigns to ensure a good agreement throughout the simulation period, substantially better than when MAR is forced by ERA5 SSCs (HadISST2). We also investigate the influence of the sea ice extent drop on SMB observed between the 70s and the 80s, analogous to the one observed in 2016. This extended dataset offers improved insight into past ice sheet mass changes and highlights the importance of long-term SMB reconstructions for further understanding the role of the Antarctic ice sheet in Earth's climate system.