Barents-Kara sea ice and European winters in EC-Earth

• Published in: Climate Dynamics
• Main Authors: Ringgaard, Ida Margrethe, Yang, Shuting, Kaas, Eigil, Christensen, Jens Hesselbjerg
• Other Authors: FP7 Ideas: European Research Council
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2020
• Subjects: Atmospheric Science; Kara Sea; Sea ice
• Online Access: http://dx.doi.org/10.1007/s00382-020-05174-w; http://link.springer.com/content/pdf/10.1007/s00382-020-05174-w.pdf; http://link.springer.com/article/10.1007/s00382-020-05174-w/fulltext.html

Abstract The potential link between decreasing Barents-Kara sea ice and cold winters in Europe is investigated using the enhanced resolution (horizontal atmospheric resolution of $$\sim 80\,\hbox {km}$$ ∼ 80 km ) global, coupled climate model EC-Earth. Nudging sea ice only in the Barents-Kara Seas, five configurations of sea ice covers are used to assess the importance of the amount of sea ice in this region. Nudging in the coupled model is achieved by modifying the non-solar surface heat flux into the ice/ocean interface. The mean winter temperature response suggests a weak but statistically significant non-linear response with cooling over eastern Europe for moderate sea ice reductions in the Barents-Kara Seas, a weaker but still cold anomaly for minor reductions and warming for major reductions. However, this non-linear response is not reflected in the circulation. Instead, a negative mean sea level pressure anomaly over Barents-Kara Seas intensifies with sea ice reduction. In contrast to this, is the response in the coldest winters over central Europe: the larger the sea ice reduction, the stronger the Scandinavian pattern and the associated easterlies need to be to obtain cold winters over central Europe. The use of a coupled climate model is a potential explanation for the link between the intensified Scandinavian pattern and the cooling over Europe seen in this study, that is not observed in some atmosphere-only model studies.