利用西北干旱区83个气象站点1961—2012年逐日最低(高)气温资料,对其极端温度事件季节性时空变化规律进行分析与预测,以期更好地为其生态保护和农业生产服务。结果表明:(1)时间趋势上,日极端低(高)温均值呈上升趋势,尤其是1981年后升幅明显增加,冬秋季升温最显著;日极端低(高)温极低(高)值有增多趋势,其中暖昼(夜)日数有增加趋势,夜(昼)指数变化最快的季节为夏秋季;1979—1986年,上述指数变化趋势发生突变(冬季先开始);除夏季日极端低温极低值外,其他指数在2013—2020年季节变化与1961—2012年的增减趋势一致;(2)空间分布上,暖昼(夜)日数最大值、冷昼(夜)日数最小值均在北疆分区,而内蒙—宁夏分区的增减速率变化最快;2013—2020年,新疆全境春季冷昼、冷夜日数急剧减少,内蒙—宁夏分区、南疆分区夏季日最低(高)气温极值急剧降低(上升)。
Based on daily minimum and maximum temperature data of 83 meteorological stations in arid region of northwest China during 1961-2012, we analyzed and predicted seasonal spatio-temporal variation law of extreme temperature events, so as to provide better service for ecological protection and agrieuhural production. The results showed that: (1) from the trend of time, the average daily minimum/maximum temperature (T.~ or Tm ) had an ascending tendency especially after 1981, and had the most significant ascending tendency in winter and autumn; extra-minimum air temperature (TNn) and extra-maximum air temperature (TXx) had a rising trend, warm days (TX90p) and nights (TN90p) had an increasing trend, it was worthwhile to note that the most significant change above was the night indices in summer; additionally, mutations were found firstly in winter during 1979-1986, apart from the variation rate of TNn in summer, the seasonal and seasonal variations of the other indices in the period 2013-2020 would be consistent with the increase and decrease in the period of 1961-2012; (2) from spatial distribution, the maximum number of warm days (nights), the minimum number of cold days (nights) were in the northern division of Xinjiang, while Inner Mongolia-Ningxia division had the fastest rate of change; during 2013-2020, the cold days and nights in spring in Xinjiang would decrease sharply, and the extreme minimum (maximum) temperature of summer days would decrease (increase) drastically in the Inner Mongolia-Ningxia division and southern Xinjiang division.