印度夏季风的年代际变化与我国北方的气候跃变

THE INTERDECADAL VARIABILITY OF INDIAN SUMMER MONSOON AND THE CLIMATE STATE SHIFT IN NORTH CHINA

关键词:  印度夏季风  年代际变化  气候跃变

Key words:  Indian summer monsoon  interdecadal variability  climate regime shift

摘要:

利用NCEP/NCAR再分析资料及台站实测资料分析了近几十年印度夏季风的年代际变化特征及我国北方所发生的气候变化,揭示了印度夏季风的减弱与我国北方地区的气候演变具有密切的联系。分析结果表明:在1960年代中期和1970年代后期印度夏季风环流经历了两次明显的减弱过程,这两次减弱过程的出现与我国北方地区所发生的气候跃变在时间上十分接近;印度夏季风的年代际变化与北方地区(包括华北、东北、蒙古东部及朝鲜半岛)对流层温度变化存在显著的正相关关系,北方地区对流层温度的不断下降改变了海陆之间的热力对比,从而引起印度夏季风的减弱。

Abstract:

The interdecadal variation of Indian summer monsoon and the climate shift in North China are analyzed by using of NCEP-NCAR reanalysis data and the stations observations. It reveals the strong connections between the climate regime shift in North China and the weakening of the Indian summer monsoon circulation. The result shows that Indian summer monsoon circulation underwent two weakening processes in recent decades. The first occurred in the mid-1960s, and the other occurred in the late 1970s. The two weakening processes were very well coincident with the regime shift that occurred in North China. It also shows significant positive correlations between mean tropospheric temperature over the North region(including North China, Northeast China, East Mongolia and Korea Peninsula) with the interdecadal variation of Indian summer monsoon. The declining of the mean troposphere temperature over the North region may lead to the weakening of the Indian summer monsoon intensity via the changing of land-sea thermal contrast.