东亚冬季1000 hPa环流异常与我国气候的关系

ANOMALOUS WINTER CIRCULATION AT 1000hPa OVER EAST ASIA AND ITS RELATION TO CLIMATE CHANGE OVER CHINA

将NCEP/NCAR 1951/1952～2003/2004年东亚冬季1 000 hPa风场进行向量EOF分解,研究其第一特征模态的时空变化及其与我国气候异常的关系。结果表明,EOF1时间系数能够很好地刻画东亚冬季风的强度变化。强(弱)EOF1时间系数时,冬季我国气候冷、干(暖、湿),次年春季东北及河套等地区的温度明显偏低(高);次年夏季长江中下游地区的降水明显偏少(多),华北和华南降水则偏多(少),长江流域和江南地区的温度偏高(低),华南及西南地区夏季则温度偏低(高)。

The relationship between the spatial and temporal variation characteristics of the first mode （EOF1） of East Asian winter monsoon and climate change in China is revealed by using the vector EOF expansion of winter wind fields at 1 000 hPa over East Asia during 1951/1952-2003/2004. Study shows that EOF1 time coefficient can represent the intensity change of the East Asian winter monsoon well. The high （low） EOF1 time coefficient is associated with cold and dry （warm and rainy） winter, which gives rise to cold （warm） spring in the Great Bend area of Yellow River and northeast China, dry （rainy） summer in the lower and middle reaches of the Yangtze River while climatic conditions are opposite in North China and South China areas, higher （lower） temperature occurring over the Yangtze River valley and lower （higher） temperature over southern and southwestern China.