Analysis on the Characteristic of Temperature Change in the Last 50 Years in Xi'ning of Qinghai Province

Based on the data of annual average temperature,average maximum and minimum temperature,extreme maximum and minimum temperature during 1961-2010,the climatic characteristics of temperature change were analyzed in this paper.The results show that in recent 50 years,seasonal and annual average temperature presented increasing trend in Xi'ning,and was most obviously in winter.The stability of linear trend,tendency and abrupt change phenomena for maximum and minimum temperature variation presented obvious non-symmetry features.The linear trend of seasonal average maximum temperature was stable,the linear warming trend of the average minimum temperature in winter and summer was stable,the tendency rate of seasonal and annual maximum temperature was more greater than that of minimum temperature,and the linear tendency in cold season was significantly more than that in warm season.The increasing trend also presented in extreme maximum temperature,but extreme minimum temperature showed a weak downward trend.The abrupt change of extreme minimum and annual average minimum temperature occurred in 1963,but for extreme maximum and average maximum temperatures it occurred in the 1990s.