Analysis of temporal-spatial variation characteristics of extreme air temperature in Xinjiang, China

Based on data from 1961 to 2007, this paper discusses the variation trend and the periodic temporal-spatial patterns of the extreme air temperature in Xinjiang by means of the Mann-Kendall monotonous trend test and wavelet analysis. The results are as follows: (1) In the north, south and east of Xinjiang, the annual average maximum air temperature, annual average minimum air temperature and annual minimum air temperature all rose remarkably, while the rise of the annual maximum air temperature was not significant. (2) The rising trend of the annual average maximum air temperature was stronger in the east than in the north, and it was weakest in the south. The rising trend of annual average minimum air temperature was strongest in the east, followed by the south and the north. The annual maximum air temperature rose more strongly in the south than in the north, and the rise was weakest in the east. The change in annual minimum air temperature was higher in the south than in the east and was lowest in the north. (3) The mean values of annual average maximum temperature, annual average minimum temperature, and annual minimum temperature were highest in the south, followed by the east and north. The mean value of annual maximum temperature was highest in the east, followed by the north, and it was the lowest in the south. (4) Significant periodic variations with periods of 3-11 years appeared in the extreme air temperatures. (5) Wavelet coefficients can predict well the variation trend of extreme temperature in the future based on a significant period. These results can be applied in early warning of meteorological disasters and in realizing sustainable agricultural development in the study area.