Impact of sea ice cover shrinkage on the atmospheric conditions in mid and high latitudes of the Northern Hemisphere

Abstract

AbstractWe found substantial differences in the atmospheric response to sea ice area (SIA) loss depending on sectors and seasons. In the Eurasian sector, the highest SIA reduction occurred in the last 15 years, whereas in the American sector, single years of low SIA were also observed in the last two decades of the 20th century and at the beginning of the 21st century. For years of the lowest SIA in the Eurasian sector, the strong warming in the Barents and Kara Seas (BKS) and cooling in central Asia is created, giving rise to the Warm Arctic Cold Eurasia (WACE) pattern development. The enhancement of high‐pressure centre over Asia and the formation of Ural Blocking follows these anomalies. After the low SIA in May–June in the Eurasian sector, in summer, the very strong Greenland Blocking is created, reaching the North Pole and the whole of Eurasia (only in August), increasing in magnitude with altitude, which gives much warmer conditions in the North American high‐latitude region (NAH), BKS, and Europe. For the years of the lowest SIA in the American sector, the Pacific High is much more developed and extended in the entire vertical profile. This strong positive anomaly brings colder weather in Alaska and the western United States. It is most apparent after low SIA in summer and autumn and is probably due to significant changes in sea ice cover over the Chukchi Sea during that time. At the same time, the Aleutian Low is deepened in the Kamchatka neighbourhood.