5月华南降雨前期海温信号特征分析  

Characteristics Analysis of Preceding Sea Surface Temperature Signals of May Rainfall in Southern China

作　　者：张成扬[1,2] 蒋跃林[1] 杨崧[2] 胡春迪 张团团 邓开强 

机构地区：[1]安徽农业大学资源与环境学院,合肥230036 [2]中山大学环境科学与工程学院,广州510275 [3]南京大学大气科学学院,南京210093

出　　处：《气象与环境科学》2015年第2期29-35,共7页Meteorological and Environmental Sciences

基　　金：国家自然科学基金项目(41375081);灾害天气国家重点实验室开放课题(2013LASW-A05)资助

摘　　要：利用国家气象信息中心提供的1983—2013年31 a月平均全国降雨数据、美国国家环境预报中心/国家大气研究中心(NCEP/NCAR)大气再分析资料及美国国家海洋大气管理局(NOAA)的海表面温度资料,分析了华南前汛期(5月)降雨的前期海温信号。结果表明,华南5月份降雨在印度洋和太平洋的早期海温信号于1998年前后有显著的年代际变化。1998年之前,前期海温信号主要是和处于发展位相的厄尔尼诺有关的热带东太平洋和北印度洋的海温异常,它主要通过大气桥作用激发的菲律宾反气旋影响华南5月降雨异常。1998年之后,前期海温信号主要是和中高纬北太平洋的马蹄形海温异常有关,它可以通过影响中纬度瞬变活动调制副热带急流的强度和位置,引起华南降水异常。利用2014年4月的海温信号对5月华南降水的预报结果及5月的大气环流,验证了这种海温信号的存在及其引起华南5月降雨异常的机理,并运用美国国家环境预报中心气候预报系统(CFSv2)的模式预报数据,证实了这两类前期海温信号的存在。本研究表明,这两类前期海温信号能为5月份华南降雨未来的业务预报提供一定参考。This study investigated the preceding sea surface temperature （SST） signals of May rainfall in southern China and by analyzing the national monthly average precipitation data （1983--2013） provided by National Meteorological Information Center, the National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） reanalysis data, and NOAA SST data. The results showed that preceding SST signals of May rainfall over southern China in the Indian Ocean and Pacific Ocean had significant inter-decadal variation around 1998. Before 1998, the preceding SST signals of rainfall were mainly correlated with the SST anomalies of the tropical eastern Pacific and the southern equatorial Indian Ocean. The SST anomalies were associated with the developing phase of ENSO, and had effect on southern China rainfall by the Philippine Sea anticyclone forced by the atmospheric bridge. After 1998, the preceding SST signals were mainly correlated with U-shaped SST anomalies in the mid-high latitudes of North Pacific, which could modulate the location and amplitude of subtropical jet stream by the transient activity in the mid-latitude, and had effect on May rainfall of southern China. Forecasting results of May rainfall of southern China by SST signals in April 2014 and atmospheric circulation in May 2014 proved the existence of this SST signals as well as related mechanisms of anomaly May rainfall over southern China. These two early signals were found in the model forecasts data by the NCEP Climate Forecast System version 2 （ CFSv2）. Thus these two kinds of early SST signals can be applied to the prediction of the May rainfall over southern China.

关 键 词：5月 华南前汛期降雨 前期信号 可预报性 

分 类 号：P434[天文地球—大气科学及气象学]