青藏高原冬春季雪盖对东亚夏季大气环流影响的数值试验

利用ＩＡＰ２－ＬＡＧＣＭ进行了青藏高原冬春季雪盖异常对东亚夏季大气环流、加热场和降水影响的数值试验。结果表明，该影响十分显著，持续性很强。当高原冬春季雪盖异常增厚、范围扩大时，夏季（ＪＪＡ）高原地区及我国北方５００ｈＰａ位势高度降低，南方变高，西太平洋副高减弱。大气对雪盖异常的响应呈明显的波列特征。我国北方大部地区土壤温度降低，南方土壤温度升高。夏季各月降水异常分布形势并不完全一致，但与同期５００ｈＰａ高度场异常分布形势有关。

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