1971-2015年北疆地区不同等级冷空气时空统计特征分析

选取北疆50个测站1971-2015年的逐日平均气温和最低气温资料，运用小波分析、M-K突变检验等统计方法分析了北疆地区不同等级冷空气活动过程的时空变化特征。分析表明：近45年北疆地区冷空气活动持续日数在1～15d，平均持续日数为1.79 d。其中弱冷空气过程持续日数以1～2 d为主；中等强度冷空气、较强冷空气和寒潮过程以1～3 d为主；而强冷空气过程以2～4 d为主。近45年北疆单站冷空气发生频次为95.3次/a，且具有盆地多、山地少的特点；其中中等强度冷空气为11.8次/a，自东向西逐渐减少；弱冷空气、较强冷空气发生频次为70.9次/a、1.8次/a，呈自西南向东北逐渐减少的趋势；强冷空气和寒潮发生频次为4.2次/a 、7.3次/a，呈现由西南向东北增加趋势。近45年北疆地区冷空气活动频次总体呈减少趋势，年代际表现为先减少后增加的特点, 70年代最多，90年代最少，减少速率为0.33/10a；弱冷空气和较强冷空气呈增加趋势，增加速率为0.17/10a和0.03/10a；中等强度冷空气、强冷空气和寒潮活动频次呈下降趋势，其中寒潮的下降速率达-0.37/10a；不同等级冷空气活动频次均存在一个15-20a的显著周期，突变点出现在1980、2003年左右。

Analysis of Spatial and Temporal Statistical Characteristics of Cold Air in Different Levels of Northern Xinjiang in the Last 45 Years

The daily average temperature and minimum temperature data of 50 stations in northern Xinjiang from 1971 to 2015 were selected in this paper. The spatial and temporal variation characteristics of cold air activity in the northern Xinjiang region were analyzed by using wavelet analysis and m-k mutation test, analysis in the paper indicates that: In the last 45 years, cold air activity in the northern Xinjiang region lasted from 1 to 15d, with an average duration of 1.79 d. The duration of the weak cold air process is 1 ~ 2 d. Moderate strength of cold air, strong cold air and cold wave process with 1 ~ 3 d mainly. The strong cold air process is mainly 2 ~ 4 d. In the last 45 years, the frequency of cold air in the north Xinjiang single station was 95.3 /a. It has the characteristics of more basin and less mountainous area. The moderate cold air was 11.8 /a. From east to west gradually decreases. Weak cold air, strong cold air frequency is 70.9 times /a, 1.8 times /a, trend of decreasing from southwest to northeast. The occurrence frequency of strong cold air and cold wave is 4.2 /a and 7.3 /a. The trend was increased from southwest to northeast. In the last 45 years, the frequency of cold air activity in northern Xinjiang has decreased. The annual intergenerational performance is characterized by a reduction in the first generation. most in the 70 s and least in the 90 s. The reduction rate is 0.33/10a.Weak cold air and strong cold air show an increasing trend. The increase rate is 0.17/10a and 0.03/10a.The frequency of moderate cold air, strong cold air and cold wave is decreasing. The decrease rate of the cold wave is -0.37/10a.There is a significant period of 15-20a in the frequency of cold air activity in different grades. The mutational site around 1980,2003.