西北地区气候异常与前期环流场异常的关系

利用奇异值分解法(SVD)分析了西北地区季节(春、夏、秋)降水、冬季气温异常与前期高空环流异常的关系,结果表明:前期的高空环流异常对西北地区季节降水、冬季气温异常有重要影响,且与各季节降水和冬季气温异常相对应的前期高空环流异常在前期不同阶段各有其特点.前期的高空环流异常对季节降水和冬季气温异常有一定的预测意义.

Study on the Relationship between the Climate Change in Northwest China and the Abnormality of Earlier Circulation

Drought is the most significant climatic characteristic in northwest China,and the shortage of water resources is the main factor restricting the social and economic development.Therefore,it is of significance to research the climate change and predict the climate change trend in northwest China.The observation data reveal that the precipitation in spring,summer and autumn occupies over 95% of the annual precipitation in most regions of northwest China,and the climatic warming is significant in northwest China since recent 50 years,especially in winter.In this paper,the SVD method is used to analyze the relationship between the climate change(seasonal precipitation in spring,summer and autumn and air temperature in winter) in northwest China and the abnormality of earlier upper-air circulation.The results reveal that the abnormality of earlier upper-air circulation with different characteristics at different stages significantly affects the seasonal precipitation in spring,summer and autumn and the air temperature in winter in northwest China.There are the positive correlations between the winter temperature in northwest China and the abnormality of the circulation at 500 hPa over the zone from the Baikal to the Balkhash in previous spring and summer,and the intensity of subtropical high in previous autumn.There is a positive correlation between the abnormality of spring precipitation in northwest China and the abnormality of East Asian trough in winter of the same year.The abnormality of summer precipitation in northwest China is closely related to the abnormality of equatorial upper-air circulation in spring.The data of the abnormality of earlier upper-air circulation are of significance to predict the seasonal precipitation in spring,summer and autumn and the air temperature in winter in northwest China.