中国南方多雪年环流特征及对关键区海温的响应  

Response of the Atmospheric Circulation with Heavy Snow over Southern China to the Sea Surface Temperature Anomaly in the Key Areas

作　　者：常蕊[1] 张庆云[1] 彭京备[1] 

机构地区：[1]中国科学院大气物理研究所灾害性气候研究与预测中心

出　　处：《气候与环境研究》2008年第4期468-477,共10页Climatic and Environmental Research

基　　金：中国科学院大气物理研究所创新基金领域前沿重点项目IAP07120;中国科学院知识创新工程重要方向项目KZCX3-SW-226;国家自然科学基金资助项目40775037

摘　　要：根据NECP/NCAR月平均再分析资料,采用回归分析、合成分析等方法,探讨了La Nia(ElNio)气候背景下,大气外强迫因子北大西洋中纬度(45°N,30°W)、赤道印度洋、我国南海和东海海域海温异常对亚洲环流及我国南方降雪多寡的影响。分析发现,La Nia气候背景下,北大西洋中纬(45°N,30°W)海温为正异常,有利于500 hPa高度场亚洲中高纬叶尼塞地区(50°N,90°E)位势高度偏高并出现阻塞型,也有利于东亚冬季风环流加强;赤道印度洋、我国南海和东海附近海温出现负异常,850 hPa高度东亚大陆沿海低纬地区风距平场出现偏北风距平,我国南方多雪,温度相对偏低。El Nio背景下,北大西洋中纬度(45°N,30°W)海温为负异常,亚洲中高纬叶尼塞地区位势高度偏低,东亚冬季风环流偏弱;赤道印度洋、我国南海和东海附近海温出现正异常,850 hPa高度东亚大陆沿海低纬风距平场出现偏南风距平,我国南方多雪,温度相对偏高。回归分析指出,冬季500 hPa亚洲中高纬叶尼塞地区(90°E附近)的位势高度正(负)异常与北大西洋中纬度(45°N,30°W)附近海温正(负)异常有关;冬季850 hPa东亚大陆沿海低纬地区偏南(北)风距平与赤道印度洋、我国南海和东海地区的海温正(负)异常有关。La Nia气候背景下的2008年1月我国南方低温、雨雪、冰冻极端灾害事件的发生可能与北大西洋中纬度(45°N,30°W)附近以及赤道印度洋、我国南海和东海海温都出现正异常有关。The response of the atmospheric circulation with heavy snow over southern China during La Ni~↑na or El Ni~↑no years to the sea surface temperature anomaly（SSTA） in the key areas was diagnosed using linear regression and composite analysis based on the monthly NCEP/NCAR reanalysis data during from January 1954 to February 2008.There were two highlighted key areas of the sea surface temperature,one was over the region around North Atlantic（45°N,30°W）,and the other was over the neighborhood of equatorial Indian Ocean,South China Sea and East China Sea（ISE）.It had been pointed out that in winter during La Ni~↑na（El Ni~↑no） years there was（was not） a blocking high in Yenisei＇s area centered at（55°N,90°E）at 500 hPa and the East Asia monsoon circulation looked stronger（weaker） than normal illustrated by the anomalous northerly（southerly） in the high-middle latitudes over eastern China at 850 hPa,which were all related to the positive（negative） SSTA over the regions around North Atlantic（45°N,30°W）.Besides,in winter during La Ni~↑na（El Ni~↑no） years the anomalous southerly in the lower latitude over eastern China looked weaker（stronger） than normal which was related to the negative（positive） SSTA over ISE.So,the air temperature of heavy snow over southern China looked lower in winter during La Ni~↑na years than El Ni~↑no years.The response of atmosphere circulation in January 2008 to the SSTAs over the two key areas was also manifested.The heavy snow and freezing rain over southern China in January 2008 was jointly impacted by the positive SSTAs over North Atlantic and ISE.

关 键 词：南方多雪 阻塞高压 异常海温 

分 类 号：P461[天文地球—大气科学及气象学]