海陆温差与中国西南地区降水的相关性分析

Correlation Analysis between Sea-Land Temperature Difference and Precipitation in Southwest China

利用1951至2015年中国西南地区14个站点的降水、气温观测资料和英国哈得来中心的HadISST海温再分析资料,基于时间序列的变化趋势和时滞相关性方法,分析了中国西南地区地表气温和邻近海域(孟加拉湾、南海和东海)海表温度的变化,构建了一个用于表征西南地区与邻近海域的海陆温差序列,探讨了不同海域海陆温差与中国西南地区降水的相关性.结果表明:1)孟加拉湾和南海海域海陆温差与西南地区降水的相关系数均达到0.8左右,呈显著相关,而东海海海域海陆差异与西南地区降水的相关系数为0.7左右,呈中度相关;2)不同海域海陆温差对西南地区的降水关系存在着一定的延迟和同期效应.海陆温差变化对西南纬度较高地区降水具有延时和同期效应,而对纬度较低地区的降水具有超前效应,且海陆温差对低纬度地区比高纬度地区的影响较大.这表明中国邻近海域海陆温差的变化可能对我国西南地区的降水有着较为重要的影响.

By using the precipitation and temperature observation data of 14 sites in Southwest China in the period from 1951 to 2015,and the reanalysis data of HadISST,this study analyzed the changes of the surface temperature of the southwest China and the sea surface temperature in the adjacent sea areas（Bengal,South China Sea and East China Sea）based on the variation trend of time series and the time-delay correlation method.An index of sea-land temperature difference was built to represent the characteristics of the sea-land temperature difference between southwest region and its adjacent seas.Then the correlation between the sea-land temperature difference in different sea areas and precipitation in southwest China was discussed.The results are that：（1）the correlation coefficients between the precipitation in Southwest China and either sealand temperature difference of the bay of Bengal or of the South China Sea are about 0.8,indicating significant correlations,and the correlation coefficient between the sea-land temperature difference of the East China Sea and the precipitation in Southwest China is about 0.7,which is a moderate correlation.（2）sea-land temperature difference in different sea areas has delayed and immedi-ate effect on the precipitation in southwest region.Changes of sea-land temperature difference has delayed effect and immediate effect on the precipitation in high-latitude regions in Southwest China,and has advanced effect in low-latitude areas.Sea-land temperature difference has a greater impact on the low-latitude areas than the high-latitude areas.The results indicate that the change of sea-land temperature difference in adjacent sea areas may have important influences on the precipitation of Southwest China.