ANALYSES ON MONTHLY MEAN TEMPERATURE AND ANOMALOUS DISTRIBUTION OVER QINGHAI-XIZANG PLATEAU IN WINTER AND SUMMER

In this paper, utilizing the data of monthly mean temperature over Tibet (15 stations) and Qinghai (38 stations) in winter and summer and EOF REOF analysis methods, the features in temporal and spatial distribution of winter and summer temperature over the Qinghai Xizang Plateau and their change tendencies have been analysed. The results show the contribution of the first ten leading RPC accumulation variance of the summer winter temperature fields can reach 90%. Whether winter or summer, the air temperature has the feature that the speed is slow and disappearing is fast over Qinghai Xizang Plateau. After the temperatures were related, the unusual sensitive fields of the winter temperature can be divided into north , southeast , boundary and the mid and west patterns; the ones of summer temperature, into northeast , east , south , the basin and west patterns. The winter and summer temperature fields over the Plateau are heavily influcuced by not only the topography, underlying surface condition, but also the synoptic systems in winter and summer. Usually in the anomaly distribution, the westerly trough in winter and the Plateau surface thermal depression and Indian monsoon in summer may play an importand role. In the time tendency of Plateau temperature fields, the winter temperature have had warming trend in all Plateau; the same thing is true for summer temparature, especially for Northeast , South and West Plateau.