The Role of External Forcing on the Amundsen Sea Low Intensification

The Amundsen Sea Low (ASL), a semi-permanent low pressure system situated off the coast of West Antarctica, has been deepening in the last several decades, in all but winter.  The variability and change in the ASL is strongly tied to the regional climate, ranging from sea ice extent in the Ross, Amundsen, and Bellingshausen Seas, to temperature and precipitation anomalies / trends across West Antarctica and the Antarctic Peninsula.  Notably, the ASL resides in one of the most highly variable (in terms of weather) regions of the Southern Hemisphere, making it a challenge to understand the causality of these changes, and to separate any external forcing from the large natural variability.  This talk will briefly discuss the characteristics of and changes in the ASL and its connection to the regional climate.  More focus will be given on recent modeling studies aimed at understanding the causality of these changes, including the role of natural variability / tropical sea surface temperatures.