中文摘要：

为探讨北半球夏季地表潜热通量的时空分布特征及与中国夏季降水之间的关系,利用1961~2000年欧洲中心北半球夏季潜热通量和夏季中国160站降水逐月资料,并利用经验正交分解方法（EOF）、递进相关法和合成分析法,得出：夏季潜热通量第一模态空间分布呈＂南负北正＂型,模态的时间序列以20世纪70年代中期为界,表现出＂前正后负＂的变化特征;夏季潜热通量第二模态空间分布表现为＂全区一致＂型,模态时间系数序列以70年代中期为谷底,表现出＂单谷＂变化特征。北半球夏季潜热通量第一模态时间序列与中国夏季降水相关系数以西北地区为界,分为两大特征：西北地区表现为全区为负,其余地区从南向北表现为＂正负正负＂的分布,表明70年代中期以前（后）,北半球中高纬度潜热通量为正（负）,西南地区及华北地区降水偏多（少）,江淮流域地区降水偏少（多）。中国江淮地区夏季降水序列与北半球夏季地表潜热通量相关系数显著负相关区位于鄂霍次克海以北,对该区域的地表潜热通量做区域平均,得出1985年前为正潜热通量值,1985年后为负潜热通量值对应1985年前我国江淮地区降水合成为负,1985年后降水合成为正的结果。

英文摘要：

In order to study the characteristic of spatial and temporal distribution of the surface latent heat flux in summer and its relationship to the summer precipitation in China,the article use the Northern hemisphere surface latent heat flux data of summer from 1961- 2000 provided by ECWMF,the precipitation data from National Climate Center and use the methods of EOF,progressive correlation and component approach to analyze the characteristics of spatial and temporal distribution of the surface latent heat flux in summer and discuss its relation to the summer precipitation in china. The results show： the first modal space distribution of summer latent heat flux is‘south negative north positive＇; Its time sequence is bounded by the mid-1970-s,showing the change rule of ‘former positive later negative＇; the second modal space distribution of summer latent heat flux is almost consistent in northern hemisphere; Its time coefficient series shows the characteristic of ＂single valley＂and in mid-1970-s for its bottom. The correlation coefficient of the first mode time series of northern hemisphere summer latent heat flux and summer precipitation in china shows the distribution of ‘ ＋-＇. It proves that efore（ after） mid 70 s,the latent heat flux in high latitudes is positive（ negative）,the southwest and northern China had more（ less） precipitation,while Jianghuai watershed area had less（ more）. The correlation coefficient of significantly negative area is north of the sea of okhotsk for summer precipitation region sequence in yangtze-huaihe and surface latent heat flux in the northern hemisphere. The average surface latent heat flux of this area shows that ‘positive＇before 1985 ‘negative＇after 1985,corresponding to the precipitation ‘less＇ before 1985 ‘more＇after1985 in yangtze-huaihe area.