2013年海洋和大气环流异常及对中国气候的影响  

Anomalies of Ocean and Atmospheric Circulation in 2013 and Their Impacts on Climate in China

作　　者：司东[1,2] 袁媛[1] 崔童[1] 孙冷[1] 王东阡[1] 柳艳菊[1] 郭艳君[1] 王遵娅[1] 

机构地区：[1]中国气象局气候研究开放实验室,北京100081 [2]南京信息工程大学气象灾害预报预警与评估协同创新中心,南京210044

出　　处：《气象》2014年第4期494-501,共8页Meteorological Monthly

基　　金：国家重点基础研究发展(973)计划(2013CB430202和2012CB955203);中国气象局气候研究开放实验室2012/2013年度开放青年基金资助项目共同资助

摘　　要：本文对2013年海洋和大气环流异常特征进行分析,讨论这些异常特征对中国气温和降水的主要影响。结果表明:2012/2013年冬季,北极涛动持续维持负位相,500 hPa位势高度场上,欧亚大陆中高纬环流呈"两槽一脊"的环流形势,乌拉尔山的高压脊持续偏强,而东亚槽也异常偏强,导致全国平均气温较常年同期偏低。季内,西伯利亚高压强度变化显著,与之相对应,我国气温季内阶段性变化大,前冬冷、后冬暖。进一步研究表明,前秋北极海冰的大幅偏少是造成东亚冬季风偏强的重要原因。2013年冬季至夏季,赤道中东太平洋海温异常偏低而海洋性大陆至西太平洋海温异常偏高,受此影响,夏季西太平洋副热带高压位置明显偏北,导致我国北方夏季多雨。与此同时,受西太平洋副热带高压下沉气流的控制,我国南方大部高温持续。2013年南海夏季风爆发偏早两候,结束偏晚4候,强度偏弱。Anomalies of oceanic and atmospheric circulations are analyzed and their impacts on temperature and precipitation anomalies of 2013 in China are discussed. The results show that the Arctic Oscillation （AO） experienced negative phase during the 2012/2013 winter. At 500 hPa, a ＂two troughs and one ridge＂ anomalous geopotential height pattern dominated the mid-high latitudes in Eurasia, leading to an enhanced ridge and trough over Urals and East Asia, respectively, and further leading to be colder than normal situ- ation over China. While the Siberian high exhibited strong intra-seasonal variations, the temperature over China had two-stage variations last winter, warmer in the early winter and colder in the late winter. Fur- ther research indicates that the reduced Arctic sea ice extent in the last autumn was responsible for the stronger East Asian winter monsoon. During the period from winter to summer 2013, the anomalous low sea surface temperature （SST） was observed in the tropical central and eastern Pacific, while abnormal high SST in tropical western Pacific and oceanic continent. As a response of atmospheric circulation to theanomalous tropical oceanic condition, the western Pacific subtropical high extended further north, leading to more precipitation over the northern part of China during the summer. Meanwhile, the northward ex- tending of the western Pacific subtropical high dominated most southern part of China, causing higher tern perature and less precipitation than normal in the region in summer. In 2013, onset of South China Sea summer monsoon was 2 pentads earlier than normal and the ending was I pentads later than normal, and the intensity was weaker than normal.

关 键 词：海温 大气环流 气候异常 

分 类 号：P461[天文地球—大气科学及气象学]