Synoptic drivers of atmospheric river induced precipitation near Dronning Maud Land, Antarctica

ARs contribute significantly to the interannual variability of precipitation over the AIS and thus are likely to play a key role in understanding future changes in the surface mass balance of the AIS. Dronning Maud Land (DML) is one of four maxima in AR frequency over coastal East Antarctica, with AR precipitation explaining 77% of the interannual variability in precipitation for this region.

We employ a 16-node self-organizing map (SOM) trained with MERRA-2 sea-level pressure anomalies to identify synoptic-scale environments associated with landfalling ARs in and around DML. Node composites of atmospheric variables reveal common drivers of precipitation associated with ARs reaching DML including anomalous high-low surface pressure couplets, anomalously high integrated water vapor, and coastal barrier jets.