关键词: 新疆阿勒泰, 冬季, 大到暴雪, 气候变化特征

Abstract: Based on the global warming background，this paper studied heavy snowstorm climate characteristics in the Altay prefeture，revealed variation law of heavy snowstorm in this prefecture，and provided reference for guiding the region economy layout，disaster prevention and mitigation，blizzard disaster risk assessment. And at the same time，this paper provided the basis for the short-term climate prediction. It used the daily precipitation data of 1961-2010 winters at seven observation stations of the Altay prefecture，defined the heavy snowstorm characteristics，and standardized the time series. With the help of Linear Trend Method，Cubic function，Mann-Kendall mutation testing，Morlet wavelet transform and R/S analysis，the heavy snowstorm characteristics of climatic change in winters.were studied.  The results show that: the total rainfall of heavy snowstorm contributes great value to the variance of the total rainfall in winters.  In the climatic distribution，the large value area of heavy snowstorm characteristic quantity and the total rainfall in winters locates in its northern and eastern parts with the large value center laying at Fuyun or Altay station，variance contribution value center at Qinghe station. Small value center locates at Fuhai station. On an inter annual scale，each characteristic quantity has 7 a periodic variation characteristics in this prefecture; In view of the inter-decadal scale，significant periodic variations are 13-15 a，17-23 a，and 28-29 a. In the time domain，rainfall and frequency of heavy snowstorm were characterized by negtive anomaly before the 1990s，change was relatively smooth，and by positive anomaly after the 1990s，and change was relatively acute. The heavy snowstorm intensity fluctuated greatly from 1960s to 1990s begining and from the mid-period of 1980s to the 2000s，the change in intensity was relatively smooth from the mid-period of the 1970s to the 1980s beginnig. The cubic function fitting shows that: The heavy snowstorm characteristics produced a type transformation from less occurrence to much occurrence in late 1980s and early 1990s，but there was no mutation point. In the spatial domain，the location of heavy snowstorm’s large value area was relatively stable for every decade，locating in the north and eastern，small value area appeared in valley and plain. Large value center appeared at Fuyun station in 1960s and 1990s，and appeared at Altay station in the other decades; small value center appeared at Buerjin station in the 1970s，and appeared at Fuhai station in the other decades. The change in frequency of the heavy snowstorm was different to the change in the large value center and appeared at Qinghe station in the 1990s; The heavy snowstorm intensity’s large value center lay at Altay station in 1960s and 1970s，at Fuyun station in 1980s and 1990s，at Habahe station in 2000s，and the large value area distribution was more complex. The heavy snowstorm characteristic quantity was with an increasing trend in the whole prefecture; the trend coefficients were 0.374，0.364 and 0.359; climate tendency was 0.22 mm/10 a，0.20 d/10 a and 0.16（mm/d）/10 a. Among these stations,the large heavy snowstorm amount appeared at Altay and Fuhai stations,the large frequency and intensity appeared at Altay and  Fuhai stations，and Fuyun station did not pass the significance test，the other stations passed the significance test. R/S analysis showes that the heavy snowstorm characteristic quantity would gradually be changed in a reduced tendency，especially at Jimunai station.

Key words: Altay Xinjiang, winter, heavy snowstorm, climate characteristic