中国西北地区气候变化与同期气象场异常的关系

利用奇异值分解法（SVD）分析中国西北地区降水和气温异常与同期高空环流和下垫面温度异常的关系。研究表明：西北地区各季降水与同期北印度洋海区、西太平洋海面温度都有较好的遥相关性；西北地区降水与同期欧亚对流层的中下层的纬向和经向环流强度的异常有明显的关系；西北地区气温异常与欧亚大陆同期中高纬向和经向环流的异常有关，冬季和秋季气温异常主要与纬向环流的异常有关，春季气温异常与经向环流异常有关。

Relationships between Climate Change and Abnormalities of Meteorological Fields during the Corresponding Period in Northwest China

Northwest China is a typical arid and semiarid region,and it is characterized by extremely complicated climate change,infrequent occurrence of precipitation,violent evaporation and shortage of surface water,so groundwater recharge from rainfall permeation is limited.In this paper,the SVD method is used to analyze the relationship between climate change and abnormality of upper air circumfluence and abnormality of underlaying surface temperature in northwest China.The conclusions are follows:(1) Seasonal precipitation in northwest China has a close teleconnection with the air temperature near sea surface of the north Indian Ocean and the west Pacific Ocean,and the seasonal change of the geographical location where the seasonal precipitation abnormality in northwest China has a close teleconnection with the air temperature near sea surface of the north Indian Ocean and the west Pacific Ocean is significant;(2) The seasonal precipitation in northwest China is closely related to the intensity of both latitudinal and longitudinal circumfluences in the middle-lower layer of troposphere during the corresponding period,and the large-scale weather systems affecting the precipitation abnormality in northwest China are the East Asian trough,Ural trough(wedge),west Pacific Ocean subtropical high and Indian Byland trough(wedge);(3) The abnormality of air temperature in northwest China is related to the abnormality of both latitudinal and longitudinal circumfluences over high latitudes,the abnormality of air temperature in northwest China in winter and autumn is related to the abnormality of latitudinal circumfluence,and the abnormality of air temperature in spring is related to the abnormality of longitudinal circumfluence.