机构地区:[1]Key Laboratory of Arid Climate Change and Disaster Reduction of Gansu Province,College of Atmospheric Science, Lanzhou University [2]Key Laboratory of Western China’s Environmental Systems, Ministry of Education,Lanzhou University
出 处:《Advances in Atmospheric Sciences》2012年第2期274-284,共11页大气科学进展(英文版)
基 金:supported by the National Basic Research Program of China (Grant No 2007CB411506);National Natural Science Foundation of China (Grant Nos 4107108 and 40875050)
摘 要:In this paper, the possible reason of Tibetan Plateau (TP) temperature increasing was investigated. An increase in T min (minimum temperature) plays a robust role in increased TP temperature, which is strongly related to SST over the warm pool of the western Pacific Ocean, the subtropical westerly jet stream (SWJ), and the tropical easterly upper jet stream (TEJ), and the 200hPa zonal wind in East Asia. Composite analysis of the effects of SST, SWJ, and TEJ on pre and postabrupt changes in T a (annual temperature) and T min over the TP shows remarkable differences in SST, SWJ, and TEJ. A lag correlation between T a /T min , SST, and SWJ/TEJ shows that changes in SST occur ahead of changes in T a /T min by approximately one to three seasons. Partial correlations between T a /T min , SST, and SWJ/TEJ show that the effect of SWJ on T a /T min is more significant than the effect of SST. Furthermore, simulations with a community atmospheric model (CAM3.0) were performed, showing a remarkable increase in T a over the TP when the SST increased by 0.5 ? C. The main increase in T a and T min in the TP can be attributed to changes in SWJ. A possible mechanism is that changes in SST force the TEJ to weaken, move south, and lead to increased SWJ and movement of SWJ northward. Finally, changes in the intensity and location of the SWJ cause an increase in T a /T min . It appears that TP warming is governed primarily by coherent TEJ and SWJ variations that act as the atmospheric bridges to remote SSTs in warmpool forcing.In this paper, the possible reason of Tibetan Plateau (TP) temperature increasing was investigated. An increase in T min (minimum temperature) plays a robust role in increased TP temperature, which is strongly related to SST over the warm pool of the western Pacific Ocean, the subtropical westerly jet stream (SWJ), and the tropical easterly upper jet stream (TEJ), and the 200hPa zonal wind in East Asia. Composite analysis of the effects of SST, SWJ, and TEJ on pre and postabrupt changes in T a (annual temperature) and T min over the TP shows remarkable differences in SST, SWJ, and TEJ. A lag correlation between T a /T min , SST, and SWJ/TEJ shows that changes in SST occur ahead of changes in T a /T min by approximately one to three seasons. Partial correlations between T a /T min , SST, and SWJ/TEJ show that the effect of SWJ on T a /T min is more significant than the effect of SST. Furthermore, simulations with a community atmospheric model (CAM3.0) were performed, showing a remarkable increase in T a over the TP when the SST increased by 0.5 ? C. The main increase in T a and T min in the TP can be attributed to changes in SWJ. A possible mechanism is that changes in SST force the TEJ to weaken, move south, and lead to increased SWJ and movement of SWJ northward. Finally, changes in the intensity and location of the SWJ cause an increase in T a /T min . It appears that TP warming is governed primarily by coherent TEJ and SWJ variations that act as the atmospheric bridges to remote SSTs in warmpool forcing.
关 键 词:TP temperature subtropical westerly jet tropical easterly jet warm pool
分 类 号:P434[天文地球—大气科学及气象学]
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