华东地区夏季高温期的气候特征及其变化规律

基于华东气象站点1961-2005 年逐日最高地面气温资料, 分析了华东高温日数和高温 日平均最高气温的时空动态变化特征。结果表明: 过去45 年间, 华东年均高温日数为15.1 天, 高温日平均最高气温为36.3 ^oC, 高温以12~15 年为显著振荡周期, 在20 世纪80 年代为 弱负距平, 而在其他时期都为正距平。华东高温日数呈北少南多的空间分布, 高温日平均最 高气温以安徽、浙江和江西较高, 高温过程数是东北部少, 西南部多。高温日数和高温过程 数是以7 月最多, 高温日平均最高气温也是以7 月最高。在21 世纪最初5 年, 站点高温日数 和高温日平均最高气温增加, 4-10 月高温都为正距平, 各级高温过程数总体最多, 各级高温 过程日平均最高气温也最高。

Climatic Characteristics and Their Changing Law during Summer High- Temperature Times in East China

Based on the daily highest temperature data covering the period 1961-2005, temporal and spatial characteristics and their changing in mean annual and monthly high temperature days (HTDs) and the mean daily highest temperature (MDHT) during annual and monthly HTDs in East China were studied. The results show that the mean annual HTDs were 15.1 and the MDHT during annual HTDs was 36.3 oC in the past 45 years. Both the mean annual HTDs and the MDHT during annual HTDs were negative anomaly in the 1980s and positive anomaly in the other periods of time, oscillating with a cycle of about 12-15 years. The mean annual HTDs were more in the southern part, but less in the northern part of East China. The MDHT during annual HTDs was higher in Zhejiang, Anhui and Jiangxi provinces in the central and western parts of East China. The high temperature process (HTP) was more in the southwestern part, but less in the northeastern part of East China. Both the numbers of HTDs and HTP were most in July, and the MDHT during monthly HTDs was also the highest in July. In the first 5 years of the 21st century, the mean annual HTDs and the MDHT during annual HTDs increased at most of the stations, both the mean monthly HTDs and the MDHT during monthly HTDs were positive anomaly from April to October, the number of each type of HTP generally was the most and the MDHT in each type of HTP was also the highest.