Winter Temperature Change for Last 40 Years in Tianshan Mountain
With the winter temperature data of Xinjiang during 1959—1998, the features of winter temperature change for the recant 40 Years in Tianshan Mountain are analyzed and compared with those in the Southern and Northern Xinjiang and the main conclusions are as follows: (1) The similarity of warm-cold stage of winter mean temperature between Tianshan Mountain and the Northern Xinjiang is greater than that between Tianshan Mountain area and the Southern Xinjiang. (2) The synchronous variability of spatial distribution of winter mean temperature is best in the Northern Xinjiang, and better in Southern Xinjiang and Tianshan Mountainous area. The reversed variability of spatial distribution of winter mean temperature is best in Tianshan Mountainous area and the Southern Xinjiang, better in Northern Xinjiang. (3) The change trends of winter mean temperature are different for three large regions during 1960s—1970s, but they all show continual warming from 1970s to 1990s, it is the warmest in the 1990s. (4) As to the extension of spatial distribution of the significant linear warming for the recent 40 years, the minimum temperature show the largest spatial extension, mean temperature larger and maximum temperature small. The warming rate of winter minimum temperature is the greatest for Northern Xinjiang, greater for Southern Xinjiang and the least for Tianshan Mountainous area. There are similar optimal periods of winter mean temperature, 27 and 29 years for Southern and Northern Xinjiang respectively. And the warming rate for Northern Xinjiang is greater than that for Southern Xinjiang. (5) A abrupt change of winter mean temperature, from low to high, occurred for Northern and Southern Xinjiang in 1979.