Impact of Snow Cover and Frozen Soil in the Tibetan Plateau on Summer Precipitation in China
In this paper, the impact and mechanism of snow cover and frozen soil in the Tibetan Plateau on the summer precipitation in China was simulated by using the RegCM3 model. It is revealed that the RegCM3 model can well simulate the impact of frozen depth of soil under different snow cover in the Tibetan Plateau on the summer precipitation in China. Different allocation of melting snow cover and thawing frozen soil in the Tibetan Plateau will result in difference in soil humidity,and then in the processes of phase change and energy absorbed by snow cover and frozen soil. Melting snow cover and thawing frozen soil will cause the surface sensible heat of deep frozen soil higher than that of thin frozen soil in abundant snow years, and then the ascending motion is stronger and the South Asia high and West Pacific Subtropical high both is enhanced. A convergence band will form in the Yangtze River valley, so the summer precipitation of deep frozen soil years is more than that of thin frozen soil years in the Yangtze River valley and central Northwest China, but less in Northeast China, North China, South China, and most Southwest China. When the snow cover is little, the water content of soil is depended on ice content, so the soil humidity of deep frozen soil will be higher than that of thin frozen soil. Therefore, the surface sensible heat in the Tibetan Plateau is weak in deep frozen soil years and the ascending motion is weak too. Both the South Asia high and West Pacific Subtropical high is weak,which will result in the summer precipitation of deep frozen soil year more than that of thin frozen soil years in Northeast China, North China, southern Southwest China, western Inner Mongolia and Xinjiang, but less in the Yangtze River valley and north of South China.
NETL
NSTL
万方数据
维普
