阿勒泰地区最低气温 ≤ 0℃日数的气候特征

Climatic Characteristics of the Frequency with Daily Minimum Temperature ≤ 0℃ in Altay Region

利用新疆阿勒泰地区1981~2018年(9月至翌年5月)完整的7个气象站的最低气温 ≤ 0℃的日数资料分析阿勒泰地区各站出现最低气温 ≤ 0℃的日数及初、终日的空间分布特征和时间分布特征。通过相关分析和显著性检验,结果表明:1) 1981~2018年阿勒泰地区各站出现的最低气温 ≤ 0℃日数的平均值、最多和最少日数的空间分布均呈自西北向西南和东南递增的特征,东部的富蕴和青河站出现最低气温 ≤ 0℃的日数明显多于中西部。2) 38a间,阿勒泰地区各站最低气温 ≤ 0℃的最多日数出现在1980年代和1990年代初,最少日数则出现在2000年代初。初日最早的年份在1980年代、1990年代和2010年代均有出现,最晚则主要出现在1990年代;在38a间,初日最早全部出现在9月,最晚为10月。终日最早出现在2000年代初,最晚则没有明显的规律;在38a间,终日最早基本全部在4月出现,最晚则在5月。3) 1981~2018年间阿勒泰地区各站出现最低气温 ≤ 0℃的日数均呈显著的减少趋势;各站年际变化的气候倾向率从小到大依次为:阿勒泰站?4.39 d/10a、青河站?4.52 d/10a、布尔津站?5.16 d/10a、哈巴河站?5.45 d/10a、福海站?6.27 d/10a、吉木乃站?6.37 d/10a、富蕴站?6.66 d/10a。

Based on the complete data from seven weather stations in Altay region of Xinjiang, the frequency with daily minimum temperature ≤ 0?C from 1981 to 2018 (from September to May of the following year) is obtained and the spatial and temporal distribution of the yearly first and last days with daily minimum temperature ≤ 0?C is researched. With the method of correlation analysis and significance test, it can be concluded as following tips: 1) The spatial distribution of the average, maximum and minimum of the frequency in all stations shows the trend that the frequency increases from northwest to southwest and southeast. The frequencies of Fuyun and Qinghe stations, which are in the eastern part of Altay, are significantly higher than those in the central and western parts. 2) During the 38 years, the maximum frequency in Altay occurred in the 1980s and early 1990s, while the minimum frequency occurred in the early 2000s. The earliest first day appeared in the 1980s, 1990s and 2010s, while the latest appeared mainly in the 1990s. The earliest first day appears in September and the latest in October. The earliest last day appeared in the early 2000s and there is no obvious characteristic about the latest last day. Almost all the last days appear in April at the earliest and May at the latest. 3) The frequency in all stations shows a significant decreasing trend from 1981 to 2018. The interannual change rates of the frequencies in these stations are sorted by number as following: ?4.39 d/10a in Altay station, ?4.52 d/10a in Qinghe station, ?5.16 d/10a in Buerjin station, ?5.45 d/10a in Habahe station, ?6.27 d/10a in Fuhai station, ?6.37 d/10a in Jimunai station, ?6.66d/10a in Fuyun station.