Warm Arctic−cold Siberia: comparing the recent and the early 20th-century Arctic warmings

• Published in: Environmental Research Letters
• Main Authors: Martin Wegmann, Yvan Orsolini, Olga Zolina
• Format: Article in Journal/Newspaper
• Language: English
• Published: IOP Publishing 2018
• Subjects: climate change; climate feedbacks; sea ice reduction; Arctic warming; climate impacts; large-scale climate variability; Environmental technology. Sanitary engineering; TD1-1066; Environmental sciences; GE1-350; Science; Q; Physics; QC1-999; Arctic; Kara Sea; Climate change; Sea ice; Siberia
• Online Access: https://doi.org/10.1088/1748-9326/aaa0b7; https://doaj.org/article/f327e9f695fe44e2b724dfa20b40fecc

The Warm Arctic–cold Siberia surface temperature pattern during recent boreal winter is suggested to be triggered by the ongoing decrease of Arctic autumn sea ice concentration and has been observed together with an increase in mid-latitude extreme events and a meridionalization of tropospheric circulation. However, the exact mechanism behind this dipole temperature pattern is still under debate, since model experiments with reduced sea ice show conflicting results. We use the early twentieth-century Arctic warming (ETCAW) as a case study to investigate the link between September sea ice in the Barents–Kara Sea (BKS) and the Siberian temperature evolution. Analyzing a variety of long-term climate reanalyses, we find that the overall winter temperature and heat flux trend occurs with the reduction of September BKS sea ice. Tropospheric conditions show a strengthened atmospheric blocking over the BKS, strengthening the advection of cold air from the Arctic to central Siberia on its eastern flank, together with a reduction of warm air advection by the westerlies. This setup is valid for both the ETCAW and the current Arctic warming period.