Record-high Antarctic Peninsula temperatures and surface melt in February 2022: a compound event with an intense atmospheric river

• Published in: NPJ climate and atmospheric science 2023-12, Vol.6 (1), p.202-18, Article 202
• Main Authors: Gorodetskaya, Irina V., Durán-Alarcón, Claudio, González-Herrero, Sergi, Clem, Kyle R., Zou, Xun, Rowe, Penny, Rodriguez Imazio, Paola, Campos, Diego, Leroy-Dos Santos, Christophe, Dutrievoz, Niels, Wille, Jonathan D., Chyhareva, Anastasiia, Favier, Vincent, Blanchet, Juliette, Pohl, Benjamin, Cordero, Raul R., Park, Sang-Jong, Colwell, Steve, Lazzara, Matthew A., Carrasco, Jorge, Gulisano, Adriana Maria, Krakovska, Svitlana, Ralph, F. Martin, Dethinne, Thomas, Picard, Ghislain
• Format: Article
• Language: English
• Subjects: 704/106/125; 704/106/35/823; 704/106/694/674; 704/172/4081; Anomalies; Atmospheric circulation; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Science; Atmospheric Sciences; Climate change; Climate Change/Climate Change Impacts; Climatology; Convection; Cyclones; Earth and Environmental Science; Earth Sciences; Earth sciences & physical geography; Environmental Chemistry; Foehn; Global and Planetary Change; Global warming; Heat; Ice; Ice shelves; Land ice; Moisture content; Ocean, Atmosphere; Physical, chemical, mathematical & earth Sciences; Physique, chimie, mathématiques & sciences de la terre; Planetary waves; Rainfall; Sciences de la terre & géographie physique; Sciences of the Universe; Temperature; Trends; Weather
• ISSN: 2397-3722; 2397-3722
• DOI: 10.1038/s41612-023-00529-6

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. Here, the drivers and impacts of the event are analyzed in detail using a range of observational and modeling data. The northern/northwestern AP was directly impacted by an intense atmospheric river (AR) attaining category 3 on the AR scale, which brought 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, including acceleration of the AP ice mass loss and changes in sensitive ecosystems.