近60年我国东部区域性持续高温过程变化特征

Climatic Characteristics of Regional Persistent Heat Event in the Eastern China During Recent 60 Years

  • 摘要: 利用1961—2019年中国2407个气象站的日最高气温资料,在判别华南、长江、黄淮和华北4个区域持续高温过程的基础上,比较各区域持续高温过程的气候变化特征。结果表明:华南区域性持续高温过程跨越季节最长,从5月中旬至10月初均可能出现;华南区域性持续高温指数存在显著的线性增长趋势,其增长率最高(3.3 d·(10 a)-1)。长江区域性持续高温过程持续性强,气候平均年累积日数最多,但通常出现区域持续高温过程最迟;长江区域性持续高温指数存在线性增长趋势。黄淮区域性持续高温指数的线性增长趋势不明显,但黄淮区域历史上仅有的4次非夏季持续高温过程均发生于20世纪90年代末至21世纪初。华北区域性持续高温过程气候平均年累积日数少、结束早;华北区域性持续高温指数存在显著的线性增长趋势,线性增长相关系数仅次于华南。长江和华南两区域持续高温指数的相对强弱存在显著的年代际变化,1961—1978年长江明显强于华南,1979—2019年则为华南略强于长江。

     

    Abstract: Regional persistent heat event is extensively studied and its intensity is normally investigated from the view of regional average. Climatic characteristics of persistent heat event in 4 regions in the eastern China are analyzed on the basis of distinguishing historical persistent heat event in the South China, the Yangtze River, the Huanghuai and the North China, using the daily maximum temperature data of 2407 stations in China during 1961-2019. The definition index of regional persistent heat event is established, in which the proximity of high temperature stations, the spatial range, the temporal consistency, the regional climate characteristics and the universality of methods are synthesized. Average times of regional persistent heat event in the South China, the Yangtze River, the Huanghuai and the North China are 3.3, 2.8, 2.2 and 0.8 per year respectively, with an average duration of 5.1 d, 6.4 d, 5.0 d and 3.9 d for per event, and the average annual cumulative days in climatology are 16.8 d, 17.8 d, 11.0 d, 3.1 d. Both the duration and the average annual cumulative days of persistent heat event are the longest in the Yangtze River, indicating that the persistent heat event in the Yangtze River is the most serious in climatology among these regions. The average annual cumulative days of persistent heat event in the North China are the least, and it usually ends at the end of July or before. There is a significant linear growing trend in the persistent heat event index in the South China, the North China, and the Yangtze River. There are only 4 non-summer persistent heat events in the Huanghuai in recent 20 years. The difference in strength of the persistent heat event index between the Yangtze River and the South China has significant inter-decadal trends. The index in the Yangtze River is obviously stronger than that in the South China during the first period of 1961-1978, while the index in the South China is slightly stronger than that in the Yangtze River during the second period of 1979-2019. The difference of persistent heat event between these two regions changes by nearly 10 d over these years.

     

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