The Antarctic Peninsula (AP) experienced a new extreme warm event and record-high surface melt in February 2022, rivaling the recent temperature records from 2015 and 2020, and contributing to the alarming series of extreme warm events over this region showing stronger warming compared to the rest of Antarctica. The drivers and impacts of the event are analyzed using observational and modeling data. The northern/northwestern AP was directly impacted by an intense atmospheric river (AR), bringing anomalous heat and rainfall, while the AR-enhanced foehn effect further warmed its northeastern side. The event was triggered by multiple large-scale atmospheric circulation patterns linking the AR formation to tropical convection anomalies and stationary Rossby waves, with an anomalous Amundsen Sea Low and a record-breaking high-pressure system east of the AP. This multivariate and spatial compound event culminated in widespread and intense surface melt across the AP. Circulation analog analysis shows that global warming played a role in the amplification and increased probability of the event. Increasing frequency of such events can undermine the stability of the AP ice shelves, with multiple local to global impacts.

Irina V. Gorodetskaya, Claudio Durán-Alarcón, Sergi González-Herrero, Kyle R. Clem, Xun Zou, Penny Rowe, Paola Rodriguez Imazio, Diego Campos, Christophe Leroy-Dos Santos, Niels Dutrievoz, Jonathan D. Wille, Anastasiia Chyhareva, Vincent Favier, Juliette Blanchet, Benjamin Pohl, Raul R. Cordero, Sang-Jong Park, Steve Colwell, Matthew A. Lazzara, Jorge Carrasco, Adriana Maria Gulisano, Svitlana Krakovska, F. Martin Ralph, Thomas Dethinne, Ghislain Picard