北极海冰快速退缩情景下西伯利亚区域反气旋活动变化和温度异常联系
网络出版日期: 2025-04-11
基金资助
江苏省重点研发计划产业前瞻与关键核心技术项目(BE2022161);江苏省青蓝工程学术带头人项目;无锡学院引进人才科研启动专项
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
北极海冰变化与冬季欧亚大陆气温异常变化存在密切联系,而冬季冷高压系统的频繁活动对于西伯利亚以及东亚地区降温产生直接影响,在“北极放大”以及未来北极海冰退缩情景下,西伯利亚近地面反气旋活动如何变化值得深入探究。本研究利用基于深度学习的 Mask R-CNN反气旋客观识别算法对欧亚大陆冬季天气尺度反气旋进行识别,使用欧洲中期天气预报中心(European Centre for MediumRange Weather Forecasts,ECMWF)ERA5 再分析资料、美国国家海洋和大气管理局(National Oceanicand Atmospheric Administration,NOAA)OISST V2. 1 每日海冰密集度数据集以及 MIROC6 模式输出资料,进一步研究了在未来北极海冰迅速退缩的背景下,前期秋季海冰异常变化可能对反气旋和冷空气活动产生的影响及其机制。结果表明,1981-2022年秋季巴伦支海-卡拉海区域(Barents-Kara Sea,BKS)海冰指数减下降,而欧亚大陆中高纬度特别是西伯利亚区域的气温显著下降,冷空气质量异常堆积,反气旋活动携带的冷空气质量增多。进一步利用北极放大计划(Polar Amplification Model IntercomparisonProject,PAMIP)中的模式资料,统计欧亚大陆反气旋在未来北极海冰较少情景下的活动变化规律,发现海冰减少条件下,西伯利亚区是欧亚大陆反气旋的主要影响和生消地之一,该区域反气旋具有局地活动特征,对准定常的西伯利亚冷高压以及冷池区冷空气积聚起重要促进作用。气温在欧亚大陆北边缘增高但在欧亚大陆中纬度呈显著下降特征,伴随着欧亚大陆大部分地区极寒天数增多。进一步研究发现秋季BKS海冰状况可作为前兆因子对后期冬季反气旋活动以及气温异常产生影响,该地区海冰状况引起区域位涡经向梯度显著降低,从而使上游东欧平原阻塞发生频率增大,有利于反气旋活动增强和冷空气的输送,促使东亚冬季寒冷趋势加剧。
夏 平, 卢楚翰, 黄丁安, 陈日恒, 王 蕊 . 北极海冰快速退缩情景下西伯利亚区域反气旋活动变化和温度异常联系[J]. 高原气象, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00022
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.
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