摘要
利用中国东部地区449个气象站的日最高气温资料,应用趋势分析法等,分析了1960—2012年夏季极端高温日数、持续高温日数的时空变化特征。分析发现:北方地区、华南地区和杭州湾周围地区两个高温指数都呈现增加趋势,长江与黄河之间的中部地区都减小。而在长江下游南部地区极端高温日数显著增加,但持续高温日数却明显减少。从季节特征上看,淮河以北的地区两个高温指数主要集中在6、7月;而以南的区域主要集中在7、8月。各个地区的这两个高温指数与降水日数均呈现显著的负相关,但南北有明显的差异,北方地区负相关的在年际变率以及5 a尺度都很显著,而中部地区则只在年际尺度上显著。杭州湾与华南地区持续高温日数与降水日数的相关体现在5 a尺度上。北方极端高温的显著增加与该地区降水日数与降水量明显减少密切相关。西北太平洋副热带高压显著的西伸,与东南地区的两个高温指数的变化有关。
By using the daily maximum temperature data from 449 meteorological stations over east- ern China, and with trend analysis method, the spatial and temporal variation characteristics of the ex- treme high temperature days and the continuous high temperature days in summer during 1960-2012 were investigated. Results show that both the two high temperature indices over northern China, southern China and Hangzhou Bay surrounding areas increase significantly, while over the central regions between the Yangtze River and Yellow River, they both consistently decrease. However, in lower reaches of the Yan- gtze River, the extreme high temperature days increase significantly while the continuous high tempera- ture days decrease. As far as seasonal features are concerned, the two indices mainly concentrate in June and July over the north of the Huaihe river and in July and August over the south of the Huaihe river. Furthermore, the two indices in each region demonstrate significantly negative correlation with the precip- itation days, but obvious differences exist between the North China and South China. The negative corre- lation is significant in relation to the interannual variability and 5a decadal scale, while in central regions, it merely belongs to interannual scale. The correlations between the continuous high temperature days and the precipitation days over Hangzhou Bay and South China are found only on 5a decadal scale. In North China, the significant increasing of the extreme high temperature events is closely related with the decreasing rainy days and precipitation amount. The variations of the two indices in Southeast China can be explained by the significantly westward extending of the Northwest Pacific subtropical high.
出处
《气象科学》
北大核心
2015年第6期701-709,共9页
Journal of the Meteorological Sciences
基金
国家自然科学基金资助项目(41275093)
江苏省特聘教授项目
关键词
气温
极端高温
季节内分布
东部地区
Temperature
Extreme high temperature
Intraseasonal distribution
Southern China
