Numerical Experiments on the Effects of Qinghai-Xizang Plateau Snow Cover in Winter and Spring on General Circulation over East Asia in Summer

Numerical experiments are conducted to study the influences of snow cover anomaly over Qinghai-Xizang Plateau in winter and spring on general circulation, ground heating field and precipitation over East Asia in summer using IAP 2-L AGCM. Preliminary results show that the effects are of strong persistence and the responses over East Asia in summer (JJA) are notable. When the Plateau snow cover in winter and spring is thicker in depth and larger in extent, 500 hPa geopotential height becomes lower over the regions from the Plateau to the northern China in summer, while higher in the southern China. The intensity of subtropical high over West Pacific is weaker. The responses of atmosphere to snow cover anomaly are of obvious characteristics of wave train. The ground temperature becomes lower over the areas of the northern part of China, while higher over the southern China. The distributions of monthly precipitation anomaly are not completely the same among summer months, which are closely related to the distribution of 500 hPa geopotential height anomaly in the same period