Analysis On Change Trend Of Extreme Temperature Events In Qinghai-Tibet Plateau Based On Probability Distribution

Extreme climate events are a hot issue in the world because of their great influence on nature and economic society.Qinghai-Tibet Plateau,it is one of the most sensitive areas where is response to the global climate change.What is happening to regional extreme temperature events in the context of global warming? Based on the temperature data of 78 meteorological stations in Qinghai-Tibet Plateau in 1961-2015 years,the extreme temperature events of 78 meteorological stations were extracted.The temporal and spatial manifestations of extreme temperature event frequency and intensity in Qinghai-Xizang plateau are analyzed.Based on the principles of unity,similarity and spatial continuity of a natural geographical unit,this paper analyzes the difference of probability distribution in different regions.The main conclusions are as the follows:(1)On the temporal-spatial,the sites with less frequency of extreme high temperature events are mainly distributed in the southern part of the plateau,and the sites with more frequency of extreme hypothermia are mainly distributed in the northern region of the plateau.The intensity of the weak extreme high temperature events mainly occurred in the southern part of the plateau,and the high extreme temperature event intensity mainly occurred in the large area of the southern Plateau.The frequency and intensity of extreme high temperature events in most sites increase,and the frequency and intensity of extreme hypothermia events weaken.On this basis,the extreme temperature events on the Qinghai-Tibet Plateau plateau can be divided into Yellow River-Huangshui River Valley,north-wing area of Qilian Mountain,Qaidam Basin and north wing area of Kunlun Mountains,Qiangtang Plateaux,Qingnan Plateaux,High Valley area of South Tibet,Hengduan Mountain and Zoige Plateau and Himalaya area.The annual average temperature mutation time of each region is 1996 years,1994 years,1987 years,2003 years,1997 years,1987 years,1992 years and 1998 years respectively.(2)In the extreme temperature event frequency,the Hengduan Mountains and Zoige Plateaux in the Qinghai-Tibet Plateau have the greatest response to climate warming,both in extreme high temperature events and in extreme hypothermia events,both of which are of the highest degree and degree of weakening.The response to climate warming in the Yellow River-Huangshui River Valley is unique,and it is the only area in the plateau that is shown as an enhanced trend in extreme cold events.(3)In the intensity of extreme temperature events,the regions with higher degree of climate warming affecting extreme high temperature events are mainly located in the north of Kunlun Mountains,while the influence of extreme hypothermia events is mostly distributed in the area south of Kunlun Mountains.The Himalaya area and Yellow River-Huangshui River Valley are unique,and in the extreme high temperature event,the Himalaya region is the only one which shows a weakening trend,which is inconsistent with its frequency change characteristics.In the case of extreme hypothermia,the Yellow River-Huangshui River Valley is the only region that shows an enhanced trend,which is similar to its frequency characteristics.(4)Under the background of climate warming,the variation characteristics of frequency and intensity of extreme temperature events in different regions of the Qinghai-Tibet Plateau are different,and the change characteristics of frequency and intensity are not necessarily consistent,and can reflect the variation characteristics of regional temperature in some extent.