河南省冬季连续低温天气的时空变化特征

利用河南省分布相对均匀的49个台站1957-2008年12月-翌年2月的逐日气温资料,以最长连续低温日数及其强度为指标,采用线性趋势分析、小波分析等方法研究了河南省连续低温天气的时空变化特征,结果表明：多年平均的冬季连续低温日数全省为15.6 d。低温日数的年际变化特征明显,1984年全省平均低温日数达34.2天,为历年最长;而1965年,连续低温日数仅6.5 d,为全省平均历年最短的年份。连续低温日数不同地区存在差异：在1977年,灵宝连续低温日数高达56 d,固始48 d,为历年来连续低温日数持续较长的时段;1965、1991、1995和2007年分别在灵宝、许昌、尉氏、襄城、淮阳、沈丘、永城等地连续低温日数仅为4 d。在年代际的变化中,低温日数呈现略缩短的趋势,在6~12 a的尺度上存在有显著的振荡周期。低温强度在空间上也存在差异,大值区主要分布在豫东和豫东南地区,豫西和豫西南一带相对较小。连续低温的强度年际变化明显,且随时间有减弱的趋势,在1964年低温强度有最大值,1995年有最小值。

Spatial temporal Change Characteristics of Continuous Low Temperature Weather During Winter in Henan Province

Using the diurnal temperature observation data from 49 stations in winter during Decem-ber to February in 1957-2008,and the index of maximum continuous low temperature days and its strength,we analyze the spatial-temporal change characteristics with the method of linear trend and wave-let analysis. The main results are as follows. The mean of the continuous low temperature days is 15. 6 of Henan province during 1957-2008 and its interannual variability is evident,it＇s longest in 1984 with 34. 2 d and shortest in 1965 with 6. 5 d. The spatial distribution of continuous low temperature is heterogenei-ty： Lingbao and Gushi have the longest continuous low temperature with 56 and 48 days separately in 1977; Lingbao,Xuchang,Weishi,Xiangcheng,Huaiyang,Shenqiu and Yongcheng et al have the shor-test continuous low temperature with only 4 days separately in the years of 1965,1991,1995 and 2007. In decadal scale,low temperature days show little shorten tendency,and the period of 6-12 years is sig-nificant. The low temperature strength is also difference in spatial,and the larger values are in the east and southeast part and weaker values are in the west and southwest part. The interannual change of con-tinuous low temperature strength is obvious and has a decreasing trend. The low temperature strength has maximum value in the year 1964 and minimum value in the year 1995.