Compound Impact of the Tropical Pacific and Indian Oceans on the Record-Low Antarctic Peninsula Sea Ice Cover during Austral Spring 2022

Abstract In 2022, the austral springtime sea ice extent around the Antarctic Peninsula dropped to a record low level, and the Antarctic Peninsula experienced a record-high warming, coinciding with an anomalous strengthened Amundsen Sea low (ASL). This robust result was evidenced by both the reanalysis dataset and in situ observations. Results from data diagnoses and numerical experiments indicate that there were two concurrent sea surface temperature (SST) variabilities, La Niña and negative Indian Ocean dipole events, that had compound contributions to the rapid decline through tropical–polar teleconnections that deepened the ASL, which in turn altered Antarctic sea ice concentration via thermal advection and wind-driven drift. The weakened subtropical jet over the southern Pacific Ocean facilitated suitable conditions for the propagation of wave energy. Specifically, during austral spring 2022, the cold SST anomalies in the central Pacific dominated the El Niño–Southern Oscillation–related teleconnections, while the western Indian Ocean cooling played an essential role in triggering zonal wavenumber 3 patterns. We further highlight the importance of considering the spatial diversity of tropical SST variability in predicting Antarctic sea ice, as this may be a plausible approach to improving sea ice predictability on the interannual scale. This study provides further insights into the extreme reduction of Antarctic ice.