The Relationship between Warm Season Precipitation in Asia Continent and the Sea Surface Temperature in India-Pacific Ocean Warm Pool during the Past Half Millennium

CHEN Di; GAO Shanhong; GAO Shan; CHEN Jinnian

Abstract：The distribution characteristics ofaverage precipitation in warm season (May～Sept.) and the corresponding interannual and decadal variationsin Asia continent during the past half millennium were discussed by means of the synthetic analysis,wavelet transform,power spectrum analysis and EOF analysis.And the coupling relationship between the warm season precipitation and the variations in sea surface temperature anomaly(SSTA) in India-Pacific Ocean warm pool was analyzed using the singular values decomposition(SVD).The results showed that the distribution of the precipitationhad significant regional variations and the maximum precipitation occurred in the region affected by Asian summer monsoon.The average precipitation had a significant period of 2a,24a and 48a years.The SSTA in India-Pacific ocean warm pool indicated two patterns,region consistent one and dipole distribution,with the contribution rate 40.63％ and 13.52％ respectively.There was good coupling relationship between the precipitation and the SSTA.The contribution rate of the first two patterns in the coupled mode was 82.24 ％,suggesting the important factors affecting the precipitation.The first coupling pattern was uniform distribution one (68.59 ％),which reflected heavy rain in West South Asia,in Indochina Peninsula as well as inSouth and North China but less rainfall in the Yangtze River Basin.The second coupling pattern(13.65％) embodied the India-Pacific Ocean warm pool dipole distribution (IPOD),which corresponded to less rain in West Asia,in Northeast Asia and in most part of North China and heavy rain in Indochina Peninsula and in South China.The coupling mode with 1-year delayed precipitation was also analyzed.The first coupling pattern was India-Pacific Ocean warm pool dipole distribution and the second was uniform distribution.The contribution rate was 53.57％ and 14.18％ respectively.These results had certain reference value for the further research and prediction of warm season precipitation in Asia.