吉林省冬季极端低温变化特征

Characteristics of Extreme Low Temperature Change in Jilin Province in Winter

为研究吉林冬季极端低温的变化规律,利用吉林省15个气象观测站1970~2009年逐日平均、日最高气温及日最低气温观测资料,采用气候变化检监测与指数专家组(ETCCDI)推荐的极端低温指数方法,计算出寒潮持续日数、冷昼日数、冷夜日数、霜冻日数、结冰日数、月最低气温极大值和月最低气温极小值等7个极端低温指数的年际序列。应用线性倾向估计法、Mann-Kendall检验和小波分析等方法分析了1970~2009年吉林省冬季极端低温变化特征。结果表明,空间上霜冻日数和结冰日数都从南到北呈递减趋势,冷夜日数、寒潮持续日数的高值区和月最低气温极小值低值区都在白山市、柳河一带,最低气温极大值又从北向西南成递增趋势,符合南暖背冷的特点;时间演变特征表现为:结冰日数、冷夜日数、冷昼日数、寒潮持续日数都分别以1.7 d/10a、1.9 d/10a、0.9 d/10a、0.2 d/10a显著下降,月最低气温极大值和月最低气温极小值以0.6℃/10a、0.8℃/10a显著上升;极端指数的突变基本发生在20世纪80年代到90左右;各极端指数1970~2009年时间尺度周期变化都显著集中在20~24a。

In order to study the variation of extreme low temperature in Jilin in winter, this paper uses the daily average, the highest temperature, the lowest temperature series data of 15 meteorological stations in Jilin Province from 1970 to 2009. Using the extreme low temperature index method recommended by the Climate Change Monitoring and Index Expert Group (ETCCDI) to calculate the number of cold wave lasting days (CSDI), cold days (TX10p), cold nights (TN10p), frost days (FDO), ice days (IDO), maximum and minimum of monthly minimum temperatures (TNx and TNn). The methods of linear tendency estimation, Mann-Kendall test and wavelet analysis were used to analyze the characteristics of extreme low temperature change in Jilin Province in winter. The results show that the number of frost days (FDO) and icy days (IDO) in space is decreasing from south to north. The high-value areas of cold days (TX10p) and cold wave lasting days (CSDI) wave duration and the low-value areas of the monthly minimum temperature (TNn) are all in Baishan City and Liuhe area. In line with the characteristics of south warm and cold;the characteristics of time evolution: the number of icy days (IDO), cold nights (TN10p), cold days (TX10p), and cold wave duration days (CSDI) have decreased at rates of 1.7 d/10a, 1.9 d/10a, 0.9 d/10a and 0.2/10a, and the maximum and minimum monthly minimum temperatures (TNx and TNn) have increased at rates of 0.6˚C/10a and 0.8˚C/10a;the abrupt change of the extreme index basically occurred in the 1980s to 1990s;the periodical changes of each extreme index from 1970 to 2009 on the time scale are significantly concentrated in 20 - 24a.