摘要: |
利用1950~1999年Hadley中心海温资料、NCEP/NCAR再分析资料和中国160站降水资料,通过讨论印度洋偶极子(IOD)独立发生时及IOD与ENSO联合发生时中国夏季降水的差异,研究了ENSO对IOD与中国夏季降水关系的影响。IOD独立发生时,其正位相年以湖南为中心的华南地区夏季降水偏多;IOD与ENSO联合发生时,正位相年河套、华北地区夏季降水偏少,东南沿海地区降水偏多。ENSO对IOD与中国夏季降水关系的影响主要表现为:在华南西部、江淮流域、河套及华北地区起抵消作用,而在东南沿海地区起协同作用。还从环流场角度分析了ENSO对IOD与中国夏季降水关系影响的初步成因。 |
关键词: IOD ENSO 中国夏季降水 |
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基金项目:国家自然科学基金资助项目(40475028);江苏省气象灾害重点实验室项目(KLME060210)共同资助 |
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EFFECTS OF ENSO ON THE RELATIONSHIP BETWEEN IOD AND CHINA SUMMER RAINFALL |
LIU Xuan-fei, YUAN Hui-zhen, GUAN Zhao-yong
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Key Laboratory of Meteorological Disaster, Nanjing University of Information Science & Technology, Nanjing 210044, China
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Abstract: |
Based on 1950~1999 monthly global SST from Hadley Center,NCAR/NCEP reanalysis data and rainfall over 160 stations in China,investigation is conducted into the difference of summer rainfall in China between the years with IOD happening independently and those with IOD happening along with ENSO so as to study the effects of ENSO on the relationship between IOD and China precipitation in summer. It is shown that the summer rainfall will be more than normal in South China centered in Hunan in the years of positive IOD happening independently; the rainfall will be less (more) than normal in North China (Southeast China) in the years of positive IOD happening together with ENSO. The effect of ENSO on the relationship between IOD and summer rainfall is characterized by offset (enhancing) influence in Southwest China,the Jianghuai Basin and North China (Southeast China). The circulation cause is also examined for such an influence. |
Key words: the Indian Ocean Dipole ENSO summer rainfall in China |