The Regional, Seasonal, and Lagged Influence of the Amundsen Sea Low on Antarctic Sea Ice

The Amundsen Sea Low (ASL) is an important driver of Antarctic sea ice variations largely because of wind-driven sea ice and ocean transport anomalies. However, the nature of the relationship between the ASL and sea ice is complicated by large seasonality in the ice cover and the ASL location and depth. Here we explore these relationships as a function of region, season, and lag. We find that the ASL can have a markedly different and sometimes opposite sign influence on sea ice in some regions, such as the western Ross Sea, depending on the season. This is in part due to differing influences of ASL-related meridional and zonal winds for ice transport in different times of year. The sea ice response to ASL variations is often largest at a lag of some months and can persist for up to 8 months. Plain Language Summary The Amundsen Sea Low (ASL) is a dominant feature of the atmospheric circulation in the Southern Ocean. Variations in this low pressure center influence winds over the Antarctic sea ice that can cause anomalies in sea ice transport and ice concentration. However, because the location of the low and the sea ice cover differ seasonally, the influence of ASL variability on sea ice differs by region and season. Additionally, the sea ice can exhibit a lagged response to the ASL, resulting in sea ice anomalies many months following variations in the ASL.