Characteristics of Summer Temperature Changes in Main Agricultural Areas of Tibet from 1961 to 2017

Based on the monthly mean temperature data of 4 meteorological stations (Lhasa, Shigatse, Zedang and Jiangzi) in main agricultural areas of Tibet in recent 57 a (1961-2017) in summer, the characteristics of the summer temperature change in these areas were analyzed using the statistical diagnosis method, with the relationship between the temperature variation and the Tibetan plateau index in the same period explored. The results show that: (1) With the global warming, the summer temperature in main agricultural areas of Tibet has been undergoing significant warming trend in the past 67 a (the warming rate is about 0. 32/10 a) . (2) A striking interannual variation of summer temperature in these areas was found, which is quasi-three-year periodic oscillation. In addition, the summer temperature has a distinct climate change in 2004. (3) Furthermore, there is a significant positive correlation existing in summer temperature and the Tibet plateau index in the same period, with the characteristics of interannual change basically identical to the long-term trend changes in the areas, which indicates that the temperature in summer in the main agricultural areas of Tibet is extremely low (high) when the 500 hPa geopotential height in the plateau and the surrounding areas is extremely low (high) .