冬季中高纬地区阻塞高压活动及其气候影响

Winter Blocking Episodes and Impact on Climate over East Asia

利用1958—1996年NCEP再分析500 hPa逐日高度场资料,根据阻塞高压定义的客观标准,对亚欧地区中高纬度冬季的阻塞高压进行了统计,并进行了气候学分析。结果表明,北半球冬季阻塞高压活动有很强的年际变化,而且存在明显的地理差异。在此基础上,本文还根据阻塞高压天气学指数,建立了阻塞高压的气候学指数,并用该阻塞高压气候学指数与温度、降水两个气候要素场进行了相关统计。

Using the NCEP/NCAR daily 500 hPa reanalysis data from 1958 to 1996,the synoptic blocking activity over East Asia is analyzed based on the synoptic definition of blocking.The results show that the winter blocking activity has obvious interannual variability,but such variation is different in various regions.The highest of blocking day occur in Okhotsk region and the least,in Baikal.In this paper,the climatology index of blocking is proposed according to synoptic index.The statistical relationship between climatology index and surface temperature,and precipitation are also studied.