Variability of Anticyclone Activity and Temperature Anomaly Linkages in the Siberian Region under a Scenario of Rapid Arctic Sea Ice Retreat
2. Key Laboratory of Ecosystem Carbon Source and Sink,China Meteorological Administration(ECSS-CMA),Wuxi University,Wuxi 214063,Jiangsu,China;
3. Sanming Meteorological Bureau,Sanming 365000,Fujian,China;Online published: 2025-04-11
The variability of Arctic sea ice is closely linked to anomalous winter temperature changes over the Eurasian continent,while the frequent activity of winter cold high-pressure systems directly influences temperature reductions in Siberia and East Asia. In the context of "Arctic amplification" and projected Arctic sea ice re‐ treat scenarios,it is worth delving into how near-surface anticyclone activity in Siberia will change. This study utilizes a Mask R-CNN anticyclone objective identification algorithm based on deep learning to identify winter synoptic-scale anticyclones over the Eurasian continent. It further investigates the potential impacts and mechanisms of anomalous autumn sea ice changes on anticyclone and cold air activities under the backdrop of rapid future Arctic sea ice retreat,using data from the European Centre for Medium-Range Weather Forecasts(EC‐ MWF)ERA5 reanalysis,the National Oceanic and Atmospheric Administration(NOAA)OISST V2. 1 daily sea ice concentration dataset,and outputs from the MIROC6 model. The results indicate that the sea ice index in the Barents-Kara Sea(BKS)region declined during autumn from 1981 to 2022,accompanied by significant temperature drops in the mid-to-high latitudes of the Eurasian continent,particularly in Siberia,where anomalous accumulations of cold air mass occurred,and the cold air mass carried by anticyclone activity increased. Utilizing model data from the Polar Amplification Model Intercomparison Project(PAMIP),the study statistically analyzed the variability of anticyclone activity over the Eurasian continent under scenarios of reduced Arctic sea ice in the future. It was found that under conditions of sea ice reduction,Siberia is one of the main regions influencing the formation and dissipation of anticyclones over the Eurasian continent. Anticyclones in this region exhibit local activity characteristics,significantly contributing to the quasi-stationary Siberian cold high and the accumulation of cold air in the cold pool region. Temperatures increased along the northern edge of the Eurasian continent but significantly decreased at mid-latitudes,accompanied by an increase in extremely cold days across most of the Eurasian continent. Further research revealed that autumn BKS sea ice conditions can serve as a precursor factor influencing subsequent winter anticyclone activity and temperature anomalies. The sea ice conditions in this region result in a significant reduction in the meridional gradient of regional potential vorticity,thereby in‐ creasing the frequency of blocking events in the upstream Eastern European Plain,directing cold air to build up over Siberia. This favors the enhancement of anticyclone activity and the transport of cold air,exacerbating the winter cold trend in East Asia.
XIA Ping, LU Chuhan, HUANG Dingan, CHEN Riheng, WANG Rui . Variability of Anticyclone Activity and Temperature Anomaly Linkages in the Siberian Region under a Scenario of Rapid Arctic Sea Ice Retreat[J]. Plateau Meteorology, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00022
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