夏季欧亚中高纬持续流型特征Ⅱ:年代际变化和外源强迫

STUDY ON THE SUMMERTIME PERSISTENT CIRCULATION PATTERN FEATURES OVER ASIAN-EUROPEAN MID-HIGH LATITUDE.PART Ⅱ: DECADAL VARIANCE AND EXTERNAL SOURCE FORCE

在“夏季欧亚中高纬持续流型特征Ⅰ :流型指数与持续流型”的基础上 ,分析了夏季欧亚中高纬流型指数的年代际变化特征 ,讨论了流型指数年代际变化与我国降水年代际变化之间的联系 ,并初步探讨了加热场和海温异常的影响。结果表明 :(1)夏季欧亚中高纬流型指数有明显的年代际变化 ,且与我国江淮流域、华北的降水分别有相反的相关关系 ;(2 )外源强迫对夏季中高纬度持续环流及其年代际变化的作用是不可忽视的。

Decadal variance of the summer typical persistent circulation patterns over Eurasia mid-high latitude is analyzed based on the previous part I, and the relations between circulation pattern index's decadal variance characteristic and decadal variation tendency of the precipitation of China are discussed, and preliminary exploration of the effect of heat field and sea surface temperature has been went on. The results show: ( 1) the summer typical persistent circulation patterns over Eurasia mid-high latitude have obvious decadal variance, and the correlation between itself and precipitation over Jianghuai River basin and North China is contrary; ( 2) the decadal variance of the summer persistent circulation patterns over Eurasia mid-high latitude induced by the external source force can't be ignored.