2014年夏季浙江低温多雨的大尺度环流特征及与海温异常关系  

Large-Scale Circulation Characteristics Corresponding to the Cold and Rainy Summer of 2014 in Zhejiang Province and the Relationship with SST Anomalies

作　　者：钱卓蕾 娄小芬 马洁华[3,4] 江丽俐 罗玲 

机构地区：[1]绍兴市气象台,浙江绍兴312000 [2]浙江省气象台,杭州310000 [3]中国科学院气候变化研究中心,北京100029 [4]中国科学院大气物理研究所竺可桢-南森国际研究中心,北京100029

出　　处：《气候与环境研究》2018年第2期199-209,共11页Climatic and Environmental Research

基　　金：中国气象局预报员专项CMAYBY2015-029~~

摘　　要：利用NECP/NCAR再分析资料、国家气候中心和NOAA相关资料,研究了与2014年浙江夏季低温多雨事件相关的大尺度环流特征和海温因子。结果表明:中纬度我国东部到日本南部气旋性环流异常的存在有利于浙江夏季出现低温多雨,异常偏强偏南的西太平洋副热带高压(简称副高)是8月罕见低温多雨的直接原因;东亚—太平洋型遥相关(EAP)和欧亚型遥相关(EU)是影响浙江夏季低温阴雨的主要遥相关型,当EAP负位相和EU正位相时,冷空气容易堆积和南下,与暖湿气流交汇,有利于降水降温,8月罕见低温阴雨是EAP负位相和EU正位相协同作用的结果。进一步的分析表明ENSO暖位相激发了西太平洋上空强烈的异常下沉气流和反气旋,使得副高偏南偏强,东亚地区呈EAP波列型响应;热带印度洋海温全区一致模态(IOBW)暖位相的维持进一步减弱了8月海洋性大陆地区的对流活动;北大西洋中部海温季内的变化或许与EU位相的转变有联系。Using NECP/NCAR reanalysis data, NCC(National Climate Center) and NOAA(National Oceanic and Atmospheric Administration) relevant data, large-scale circulation characteristics and sea surface temperature corresponding to the cold and rainy summer of 2014 in Zhejiang Province are analyzed. The results are as follows. The anomalous cyclonic circulation in the middle and low latitudes from eastern China to southern Japan was conducive to cold and rainy summer in Zhejiang, while the abnormally strong and southward expanding western Pacific subtropical high was also an important factor for the extremely cold and rainy August; EAP and EU were two main teleconnection patterns that affected the abnormal cold and rainy summer in Zhejiang Province. The negative EAP(East Asia–Pacific teleconnection pattern) phase and positive EU(Eurasian teleconnection pattern) phase were in favor of cold air accumulation and southward moving. The cold and warm air intersected over Zhejiang Province, leading to cold rainy weather. The rare cold rainy August was the synergistic result of negative EAP phase and positive EU phase. Further analysis reveals that the warm ENSO phase triggered a strong abnormal descending airflow and an anticyclone over the western Pacific in August, which forced the western Pacific subtropical high to move southward and become stronger, while EAP wave trains occurred over East Asia in response. The maintenance of the warm IOBW(Indian Ocean Basin Wide) phase further weakened convective activities over the Maritime continent in August. Intraseasonal SST changes in the central North Atlantic might be associated with the shifts of the EU phase.

关 键 词：浙江夏季低温多雨 西太平洋副热带高压 遥相关 海温 ENSO 

分 类 号：P466[天文地球—大气科学及气象学]