春季欧亚积雪异常影响中国夏季降水的数值试验

 利用NCAR的新一代GCM CAM3.1版本模式，研究了欧亚大陆春季积雪异常对北半球大气环流和中国夏季降水的影响。结果表明，春季积雪异常通过改变其后夏季的土壤湿度和温度分布，造成对流层厚度场的异常，激发一个从欧洲西部到东亚的500 hPa高度场异常波列。我国南、北方处于符号相反的高度场异常区，同时降水也呈现南北相异的态势，这表明春季欧亚积雪异常是影响我国夏季降水分布的一个重要因子。

Numerical Simulation on Effect of Spring Eurasian Snow Cover on Summer Rainfall in China

The effects of spring Eurasian snow cover on Northern Hemispheric atmospheric circulation and summer rainfall in China have been explored using the latest version of general circulation model (GCM) CAM3.1 developed by NCAR. Model results show that snow anomaly in spring can cause the thickness anomaly in the troposphere and trigger a wave train of geopotential height anomalies from western Europe extending to East Asia at 500 hPa by changing the distribution of the soil moisture and temperature in succeeding summer. As a result, 500 hPa height anomalies with opposite sign are located in southern and northern China. Meanwhile, summer precipitation anomaly in southern China is out of phase with that in northern China. The results demonstrate that spring Eurasian snow cover anomaly acts as an important factor affecting the distribution of summer rainfall in China.