关键词: 欧亚积雪, 中国夏季降水, 数值模拟, 大气环流

Abstract: 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.

Key words: Eurasian snow cover, summer rainfall in China, numerical simulation, atmospheric circulation