冬季黑潮延伸体区海表面温度异常对山东半岛极端低温的可能影响  

Possible Effect of Warm SST Anomalies in the Kuroshio Extension Region on Extreme Low Temperature over the Shandong Peninsula in Winter

作　　者：冀蕊 贾英来 吴一非 张杰 Ji Rui;Jia Yinglai;Wu Yifei;Zhang Jie(Department of Meteorology,College of Oceanic and Atmospheric Sciences,Ocean University of China,Qingdao 266100,China;Zhoushan Meteorological Bureau,Zhoushan 316000,China;Quanzhou Meteorological Bureau,Quanzhou 362000,China)

机构地区：[1]中国海洋大学海洋与大气学院海洋气象学系,山东青岛266100 [2]舟山市气象局,浙江舟山316000 [3]泉州市气象局,福建泉州362000

出　　处：《中国海洋大学学报（自然科学版）》2023年第1期18-31,共14页Periodical of Ocean University of China

基　　金：山东省自然科学基金重大基础研究项目(ZR2019ZD12);国家自然科学基金项目(41975065)资助。

摘　　要：利用ERA5再分析资料,分析了山东半岛1979—2014年共36年间冬季极端低温特征,发现山东半岛地区伴随偏北大风的极端低温与黑潮延伸体区域海表面温度(Sea surface temperature, SST)暖异常密切相关,提出了该区域SST暖异常增强局地的气旋,促进山东半岛偏北大风的产生,从而引起降温的可能机制。伴随偏北大风的极端低温日数占山东半岛冬季总极端低温日数的41%,对这些伴随偏北大风的极端低温日进行合成分析,发现极端低温发生时,山东半岛处于一个气旋-反气旋式环流异常的中间位置,导致山东上空北风盛行。黑潮延伸体区域的暖SST异常加强了从海洋向大气释放的热通量,驱动了上升运动,在其上空形成次级环流,有利于异常低压的生成和发展,促进了山东半岛两侧气旋对的发生,从而引起偏北大风,造成极端低温。Using ERA5 reanalysis data, the extreme low temperature in winter over Shandong Peninsula from 1979 to 2014(36 years in total) is analyzed. It is found that the occurrence of extreme low temperature with northerly wind in Shandong Peninsula is correspond with the warm Sea surface temperature(SST) anomaly in the Kuroshio extension region. The warm SST anomaly in the Kuroshio extension enhanced the local cyclonic anomaly in atmosphere and promotes the northerly wind over the Shandong Peninsula, which is the possible mechanism for extreme low temperature in Shandong Peninsula in winter. During the 36 years, extreme low temperature days which coherent with northerly wind occupied 41% of total extreme low temperature days. The composite analysis of these northerly-wind-extreme-low-temperature days show that on the day of extreme low temperature, Shandong Peninsula located in the middle of a dipole which enhanced northerly wind(The dipole is composed of an anomalous anticyclone in the west and an anomalous cyclone from east of Shandong to the Kuroshio extension region). The cyclone on the east side of Shandong Peninsula is closely related to the warm SST anomaly in the Kuroshio extension region. The warm anomaly in the Kuroshio extension region strengthened the heat flux released from the ocean to the atmosphere, driven the upward movement, and formed a secondary atmospheric circulation, which enhanced the abnormal cyclone and promoted the occurrence of the dipole, which is the reason for the extreme low temperature in Shandong Peninsula.

关 键 词：极端低温 黑潮延伸体 偏北大风 大气次级环流 

分 类 号：P47[天文地球—大气科学及气象学]