登陆我国台风与华北夏季降水的相关

Relationship between Landfalling Typhoons and Summer Precipitation over North China

利用1957—2002年华北104站月降水量、登陆我国台风频数、海平面气压场、850 hPa流场、500 hPa高度场资料,分析了华北地区夏季降水与登陆我国台风的关系。结果表明:华北中部和东部夏季降水量与登陆我国台风频数存在着显著的正相关,中心在华北中部的河北饶阳和保定一带。在登陆台风特多年,华北中、东部夏季降水增加(偏涝),南部降水减少(偏旱);登陆台风特少年则相反。逐月分析发现,8月登陆我国台风频数与华北地区同期降水量相关最好,而且显著的正相关仍然位于华北中部和东部。多(少)登陆台风活动年无论是海平面气压距平场、850 hPa流场距平、500 hPa高度距平场还是冷空气异常,其特征均与华北中、东部夏季降水偏多(少)年相似。

Possible connections are statistically analysed between landfalling typhoon number over China and precipitation over North China during rainy seasons（from June to September） using the datasets of the monthly landfalling typhoon number, 104 stations rainfall in North China, and NCEP/NCAR sea level pressure,850 hPa streamline fields, and 500 hPa geopotential height fields from 1957 to 2002. Results show that the significantly positive correlations exist in the central and east areas of North China during rainy season with the highest correlation area situated in Raoyang and Baoding. In years with notably more landfalling typhoons, summer rainfall is enhanced over the central and east of North China, but decreased over the south, and in years with the notably less landfalling typhoons, the precipitation shows an opsite picture. Monthly analysis indicates that the most significant correlation exists in August over the central and east areas of North China too. The features of sea level pressure,850 hPa streamline anomaly, and 500 hPa geopotential height anomaly fields as well as cold air tracks in years of more （less） typhoon activity are all similar with those in yeas of more （less） summer rainfall over the center and east areas of North China.