1971-2010年河南省夏季高温日数的变化趋势分析

基于河南省109个气象站1971-2010年夏季(6-8月)逐日最高气温和平均气温资料,采用气候统计学分析方法,分析了近40年河南省夏季≥35℃、≥38℃和≥40℃高温日数的时空特征及可能的变化趋势.结果表明:1971-2010年河南省夏季3个等级高温日数在空间上呈现出豫西北高海拔和豫东南低海拔地区较多,其它地区较少的分布特征,高值中心位于豫西地区的偃师附近,在时间上无显著的线性变化趋势,但是在年代间呈现出“多-少-多”的变化特征,最近10年夏季高温日数最多；从各台站趋势变化的空间分布看,豫西北海拔较高地区台站呈增加趋势的较多,豫东和豫西南台站呈减少趋势的较多.夏季平均气温和≥35 ℃(r =0.58,n=4360)、≥38℃(r=0.39,n=4360)以及≥40℃(r=0.27,n=4360)高温日数均呈显著正相关.在全球气候变暖背景下,未来河南省高温日数将可能进一步增加,特别是≥35℃的高温日数.

Analysis on Variation Trends of Summer High Temperature Days during 1971~2010 in Henan Province

Based on the long-term climatic observational data including daily average temperature and maximum temperature from 109 meteorological stations in Henan province from 1971 to 2010,the temporal-spatial distribution characteristics of summer high temperature days(daily maximum temperature equal to or higher than 35 ℃,38 ℃ and 40 ℃) in Henan province are studied with a focus on the long-trends using the mathematical statistics.The results show that the summer high temperature days of ≥35 ℃,≥38 ℃ and ≥40 ℃ have distinct spatial patterns as more high temperature days in the northwest and southeast regions and less in other parts.The high center is located near the Yanshi station in the west.The summer high temperature days in Henan province do not have significant linear trends in the period from 1971 to 2010 and have an evolutional trend of increasing-decreasing-increasing during the four decades and the summer high temperature days are much more in recent 10 years.From the spatial distribution of trend in 109 stations,increasing trend occurred at more stations in northwest regions and decreasing trend existed at less stations in east and southwest parts.The significant positive correlations are indicated between average mean temperature in summer and summer high temperature days of ≥35 ℃(r=0.58,n=4 360),≥38 ℃(r=0.39,n=4 360) and ≥40 ℃(r=0.27,n=4 360).Summer high temperature days would increase under the background of world climate warming,especially for the high temperature days of ≥35 ℃.