秦皇岛市近57年极端气温指数变化特征

Characteristics of extreme temperature indices in Qinhuangdao City in recent 57 years

利用1957—2013年河北省秦皇岛市每日气温资料,运用线性拟合及累积距平、MannKendall突变检验法、主成分分析法和MATLAB小波分析等方法对WMO发布的10种极端气温指数进行了计算和分析。结果表明,秦皇岛市近57年来,极端最高气温、极端最低气温都有上升趋势,冰日、霜日、冷夜、冷日天数呈减少趋势,夏日、热夜、暖夜、暖日呈增加趋势。由年代际分析可知,近57年来秦皇岛市的极端气温存在阶段性的变化特征,并有突变现象的发生,大部分突变年代集中于20世纪80年代左右。秦皇岛市近57年间气温上升的原因是夏日、热夜等暖指数的增加,其中热夜和暖夜增加最明显,对气温上升趋势有较大的贡献。本文所分析的10种极端气温指数都存在30 a左右的周期,部分指数存在18 a、8 a、3 a左右的周期。极端天气现象的增加会造成干旱、病虫、洪涝等气象灾害,应做好相应的防范措施。

Using daily temperature observed in Qinhuangdao from 1957 to 2013, the methods of linearer correlation analysis were employed to calculate and analyze WMO＇s ten indices of extreme temperature. The results showed that： in the past 57 years, the extreme high temperature and the extreme low temperature had upward trends, ice days, frost days, cold days and cold days had downward trends, while summer days, hot nights, warm nights and warm days showed increasing trends. The decadal analysis showed that the extreme temperature had a stage variation and mutant phenomenon in recent 57 years, in addition, the majority mutations focused on about 1980＇s. The reason of rising temperatures was warm indices, among them, hot night and warm night increased obviously, had a large contribution to the trend of rising temperature. Ten kinds of extreme temperature indices in this paper existed about 30 a period, a part of indices existed about 18 a, 8 a, 3 a period. The increase of extreme weather events would make drought, diseases, flood and other meteorological disasters, thus preventive measures should be taken.