Relationship between land surface characteristics in the Tibetan Plateau and summer precipitation in China
In this paper,using the daily observed snow cover and frozen soil data in 72 meteorological stations in the Tibetan Plateau,AVHRR normalized difference vegetation index (NDVI) and daily precipitation data from China's 550 meteorological stations,the relationships have been analyzed between the land surface characteristics in the Tibetan Plateau and summer precipitation in China.The results showed that the spatial consistency of summer precipitation is better in the North China and the southern region of Northeast China,the middle and lower reaches of the Yangtze River and South China,with an approximation tendency among adjacent meteorological stations.Precipitation has an increasing trend in South China,the middle and lower reaches of Yangtze River and Huaihe River basin,with an increase rate of 37 mm per 10 years in the middle and lower reaches of Yangtze River,but a decreasing trend in North China.Precipitation change in South China,the middle and lower reaches of Yangtze River and North China is sensitive to the change of snow cover,frozen soil and vegetation in the Tibetan Plateau,but in Huaihe River basin it is only sensitive to the change of vegetation.The surface features in the Tibetan Plateau have been established with snow cover,frozen soil and vegetation,which has a good indication significance on the summer precipitation in middle and lower reaches of Yangtze River,Huaihe River basin and North China.The distribution of correlation coefficient between land surface conditions in the Tibetan Plateau and summer precipitation in China had "-～ + ～-" features from south to north.Finally,one conceptual model is established to describe the effect of plateau land surface conditions on summer precipitation in China.When snow cover is more (less) in winter and spring,frozen soil depth is deep (thin) in winter and vegetation is more (less) in spring,the soil humidity of plateau land in summer will be more (less) and surface sensible heat will be less (more).Thus the South Asian High and West Pacific Subtropical High will be weak (strong),so that the South China Sea monsoon will be weak (strong),resulting in more (less) rainfall over the Yangtze River basin,and less (more) rainfall in South China and North China.
NETL
NSTL
万方数据
维普
