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Impacts of Sea Surface Temperature and Atmospheric Teleconnection Patterns in the Northern Mid-Latitudes on Winter Extremely Cold Events in North China
Advances in Meteorology ( IF 2.9 ) Pub Date : 2021-03-09 , DOI: 10.1155/2021/8853457
Liping Li 1, 2 , Wenjie Ni 1, 2 , Yige Li 3 , Dong Guo 1, 2 , Hui Gao 4
Affiliation  

The frequency distribution of winter extreme cold events (ECEs) in North China and the influences of mid-latitude sea surface temperature anomalies (SSTAs) in the Northern Hemisphere are studied. The results show that (1) the frequency of single station ECEs (SSECEs) in winter increases from southeast to northwest, with a decrease before 2008 and then a significant increase. This trend abrupt change occurs in late winter. (2) When the SST in the North Pacific shows an “El-Niño-like” anomaly in winter, it triggers the negative Arctic Oscillation (−AO), positive Pacific North America (+PNA), and positive Eurasia Pacific (+EUP) atmospheric teleconnection patterns in the mid-lower troposphere. As a result, the ridge to south of Lake Baikal becomes stronger. Meanwhile, SST in the North Atlantic shows a “reversed C” negative anomaly with North Atlantic Oscillation (+NAO), (+PNA)-like and (+EUP)-like patterns, and the ridge to southwest of Lake Baikal becomes stronger. Furthermore, both cause the Siberian High to become weaker in the north and stronger in the south. With the weaker East Asia subtropical jet and stronger East Asia winter monsoon, these factors lead to a significant increase of SSECE frequency in North China. (3) When the SSTA shows an “El Niño-like” developing pattern from summer to autumn in the North Pacific, the winter SSECE frequency will be higher. (4) The purported mechanism between the mid-latitude SSTA and the winter SSECE frequency in North China is the following: the SSTA in the North Pacific in summer and autumn excites atmospheric teleconnection wave trains, and the Atlantic stores these anomaly signals. In winter, the interaction between the SSTAs in the North Pacific and the North Atlantic enhances the Eurasian teleconnection wave train. With the upstream fluctuation energy dispersing downstream, the wave train centers move eastward with the season, resulting in an increase in the frequency of the SSECEs.

中文翻译:

北中纬度海温和大气遥相关型对华北冬季极端寒冷事件的影响

研究了华北冬季极端寒冷事件(ECE)的频率分布以及北半球中纬度海面温度异常(SSTA)的影响。结果表明:(1)冬季单站ECEs(SSECEs)的频率从东南向西北增加,在2008年之前有所减少,然后显着增加。这种趋势突然发生在冬季末。(2)当北太平洋的海温冬季出现“El-Niño-like”异常时,会触发北极涛动(−AO),北美洲正太平洋(+ PNA)和欧亚大陆正太平洋(+ EUP) )对流层中低层的大气遥相关模式。结果,贝加尔湖以南的山脊变得更坚固。同时,北大西洋的海温显示为“逆C”负异常,具有北大西洋涛动(+ NAO),(+ PNA)样和(+ EUP)样,贝加尔湖西南部的山脊变强。此外,这两者都导致西伯利亚高压在北部变弱而在南部变强。随着东亚副热带高压和东亚冬季季风减弱,这些因素导致华北地区SSECE频率显着增加。(3)如果SSTA在北太平洋从夏季到秋季表现出“厄尔尼诺式”发展模式,则冬季SSECE频率会更高。(4)华北地区中纬度SSTA与冬季SSECE频率之间的据称机制如下:夏季和秋季,北太平洋的SSTA激发大气遥相关波列,而大西洋则存储了这些异常信号。在冬季,北太平洋SSTA与北大西洋之间的相互作用增强了欧亚遥相关波列。随着上游波动能量向下游扩散,波列中心随季节向东移动,导致SSECE频率增加。
更新日期:2021-03-09
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