Unprecedented North American snowstorm and East Asian cold wave in January 2016: Critical role of the Arctic atmospheric circulation
Unprecedented North American snowstorm and East Asian cold wave in January 2016: Critical role of the Arctic atmospheric circulation
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DOI：
10.1002/asl.1056
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发表时间：
2021-10
影响因子：
3
通讯作者：
Dong Si;D. Jiang;Xianmei Lang;S. Fu
中科院分区：
文献类型：
--
作者：
Dong Si;D. Jiang;Xianmei Lang;S. Fu
2016年1月21日至24日期间，北方大部分陆地地区经历了极端低温。在北美，一场历史性的暴风雪袭击了美国的北方和东部。在东亚，出现了前所未有的寒潮，导致许多地区出现了创纪录的低温。在这项研究中，观测分析显示，这两次极端事件都是由2016年1月初北极地区大气环流的显著变化引发的，该变化从同心环模式转变为偶极子模式。偶极子型导致了两个倒Ω形环流型，主导了北美和东亚。这种反Ω型环流形势导致对流层顶发生明显的折叠，将高位涡冷空气从北极平流层下部向下输送到北美对流层中下部，增强了气旋性涡度和负高度扰动，并与来自北大西洋西部和墨西哥湾流的湿空气汇合，导致美国北方和东部于1月22日至24日出现严重暴风雪。在东亚，对流层顶折叠将高位涡冷空气向下输送到东亚对流层中低层，导致1月21日至24日东亚爆发强寒潮。
During January 21–24, 2016, most land areas in the Northern Hemisphere experienced extreme low temperatures. In North America, a historic snowstorm hit the northern and eastern United States. In East Asia, an unprecedented cold wave occurred and led to record‐breaking low temperatures in many regions. In this study, observational analyses revealed that both extreme events were triggered by a remarkable change in atmospheric circulation in the Arctic region in early January 2016, which switched from a concentric ring pattern to a dipole pattern. The dipole pattern resulted in two inverted Ω‐shaped circulation patterns that dominated the North America and East Asia. The inverted Ω‐shaped circulation patterns induced remarkable tropopause folding, which conveyed high‐potential‐vorticity cold air downwards from the lower stratosphere of Arctic to the middle and lower troposphere of North America, which increased cyclonic vorticity and negative height perturbations, and converged with moist air from the western North Atlantic and Gulf Stream, resulting in a severe snowstorm in the northern and eastern United States from 22 to 24 January. In East Asia, the tropopause folding transported high‐potential‐vorticity cold air downwards to the middle and lower troposphere of East Asia, resulting in the outbreak of a severe cold wave in East Asia from 21 to 24 January.