摘要
利用中国气象局国家气象信息中心提供的1951-2004年全国160站月平均降水资料和欧洲中心提供的ERA-40再分析资料,对近50年华南前汛期降水、东北冷涡、前期北半球环状模和海温的关系进行了统计分析,定义了一个前汛期东北冷涡强度指数(NECVI),结果表明:前汛期东北冷涡强度与华南降水存在显著的正相关,东北冷涡强年,华南降水偏多,前期2-3月份北半球环状模(NAM)偏弱;反之,东北冷涡偏弱年,华南降水偏少,前期2-3月份NAM偏强。此外,前汛期东北冷涡的强度和前期的中国近海海温存在显著的负相关,前期的NAM和中国近海海温的异常可以作为前汛期东北冷涡异常的一个前兆信号,进而为华南地区前汛期降水异常的预测提供参考依据。
Based on the 1951-2004 monthly precipitation and surface air temperature of 160 Chinese stations supplied by National Climatic Center, the reanalysis data from ERA-40 datasets supplied by ECMWF with resolution 2.5°× 2.5° and the Reynolds sea surface temperature （SST） data with a resolution of 2.0°× 2.0°, the relationship among the Northern Hemisphere annual mode （NAM）, the Northeast China cold vortex （NECV） and the rainfall during the first yearly rainy period in South China has been investigated statistically and a seasonal time-scale （May-June） Northeast cold vortex index （NECVI） for the first yearly rainy period has been defined. Results demonstrate that there is significantly positive correlation between the NECV and the precipitation during the first yearly rainy period in South China, with strong NECV related to more precipitation, and vice versa. An anomalously strong NECV in the first yearly rainy period often sees a weak NAM during the previous February and March, whereas a weak NECV is usually connected with a strong NAM. In addition, the NECV has an anomalously negative relationship with the precursory sea surface temperature （SST） in offshore waters of China. The previous NAM and the SST off the coast of China might offer some predictive signals for the NECV and the precipitation in South China during the first yearly rainy period.
出处
《热带气象学报》
CSCD
北大核心
2006年第6期593-599,共7页
Journal of Tropical Meteorology
基金
国家基础研究发展规划项目"973"(No.2004CB418303)
热带海洋气象科学研究基金(No.200508)
中国气象局热带季风重点开放实验室共同资助
关键词
北半球环状模
东北冷涡
华南前汛期
旱涝
Northern Hemisphere annual mode
northeast cold vortex
first yearly rainy period in South China
droughts and rains
