Marine heatwave drivers in the ice-free Barents Sea

• Main Authors: Eisbrenner, E., Åslund, O., Chafik, L., Döös, K.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Barents Sea; Sea ice
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018375

Marine heatwaves are becoming more severe in the Barents Sea due to rising temperatures caused by climate change. Identifying marine heatwaves in this rapidly warming and partially ice-covered sea is a challenge. We address these challenges by defining the study area through careful selection of spatio-temporal boundaries, thereby focusing on areas with minimal sea-ice cover. Unlike previous studies, we compare extremes relative to two reference climate baselines, one constant and one linearly rising (compensating linear warming trends). The latter allows for analyzing the dynamic changes in the region. Our results support the expected response of extreme temperatures in the Barents Sea to a warming climate. However, the use of a rising baseline reveals no apparent change in the properties (variability or magnitude) of marine extremes. We conclude that the emergence of the climate change signal, relative to a chosen reference period, best explains previous claims of a regime shift in the early 2000s. The study highlights the key role of the atmosphere, in particular anticyclonic circulation anomalies, as the primary driver of marine heatwaves in the southeastern Barents Sea, where extraordinary marine heatwaves occurred in 2013 and 2016, both dramatically amplified by climate change.