浙江省极端气温事件年代际变化特征及城乡差异分析

Decadal Variation Characteristics of Extreme Temperature Events and Their Differences between Urban and Rural Areas

采用百分位法确定了极端温度事件,通过t检验法、气候倾向率分析了极端温度事件的年代际及年际变化特征,基于核密度估计方法揭示了四季极端温度事件年代际变化特征及城乡差异。结果表明:极端高温和低温日数分别呈现以增加为主和以减少为主的变化特征,这种趋势随时间增强,东部沿海地区最显著。四季极端高温日数增多、强度增大,夏季增多最多、冬季最少,强度增大在春冬季最强。四季极端低温日数减少、强度减小,冬季减少最多,强度减小在春季最强。浙西地区极端温度事件的年际变率小于浙东地区,浙江城市地区四季极端高温强度更强、极端低温强度更弱。

By means of the percentile method to determine the extreme temperature events in Zhejiang Province,using the t-test and the climatic trend rate method,the interdecadal and interannual characteristics of extreme temperature events are analyzed.Base on the Kernel density estimation method,the extreme temperature event decadal variation characteristics in four seasons are discussed and the differences between urban and rural areas are compared.Results show that the extreme high and low temperature days have opposite characteristics,increase and decrease respectively,and the trend strengthens along with time,especially in the eastern coastal area of Zhejiang Province.The number of extreme hot days increases,the increment is the greatest in summer and the least in winter.The strength of extreme hot weather becomes stronger,especially in spring and winter.The number of extreme cold days decreases,especially in winter.The intensity of extreme cold events becomes weaker,especially in spring.The inter-annual variability of Zhejiang extreme temperature events in the western region is weaker than that in the eastern region.Urban areas show the stronger strength in extreme high temperature and the weaker strength in extreme low temperature.