Long-term Trend of Temperature,Precipitation and Relative Humidity in the Northern and Southern Regions of the Xinjiang from 1955 to 2012

By connecting temperature,precipitation and relative humidity data of twelve national standard meteorological stations which evenly distributed in the northern and southern regions of the Xinjiang from 1955 to 2012with the existing climatic regionalization of the Xinjiang,rate of linear tendency and Mann-Kendall test were used to illustrate the change trends and detect abrupt changes of meteorological elements,respectively.We investigated climate change of the northern and southern regions in Xinjiang in the last 60 years.The results showed that:1)the trend of obvious temperature increase existed in these regions in the last 60 years,the warming rates were higher in the north,the warming rates were increasing in the order of annual average maximum temperature(Tmax)annual mean temperature(Tmean)annual average minimum temperature(Tmin);2)the abrupt change occurred both in the northern and southern regions of the Xinjiang from1987 to 1989in the north,from 1993 to 1994in the south;3)the change trend of annual precipitation was not more significant than that of the temperature changes,the overall increasing trend change was insignificant in the southern and northern regions of Xinjiang,the annual available precipitation showed the stable change in the north,but it presented the increase trend in the south,the abrupt change of average annual rainfall in southern Xinjiang occurred in 1981,while the northern curve of the positive and negative sequence did not exceed the 95% confidence level line,the adrupt change point did not appear;4)the annual average relative humidity decreased in the north,showing an increasing trend in the whole southern border,the annual relative humidity showed a increase-reduce-increase-reduce change pattern;with respect of the entire re-gion,the sharp reduction of relative humidity had been observed since the 21 st century;5)results of Morlet wavelet analysis showed that in the north and south of Xinjiang,the presence of temperature changes existed the period of 4aand 8a,precipitation and relative humidity existed the cycle of 3a,6aand 16 aaround the periodic variation.