1980年以来京津冀地区群发性高温过程的变化特征

Characteristics of Cluster High-Temperature Processes in the Beijing-Tianjin-Hebei Region Since 1980

关键词:  高温  群发性高温过程  持续性  气候特征  京津冀

Key words:  high temperature  cluster high-temperature process  persistent high temperature  climatic characteristics  Beijing-Tianjin-Hebei region

摘要:

利用 1980—2023年京津冀地区 174个气象站的逐日最高气温资料，分析高温天气的时空变化特征，确定出群发性高温过程的判识标准并进行分析，结果得到京津冀地区多年平均年高温日数为 10.8 d，整体呈显著增多趋势，气候倾向率为 1.9 d·(10 a)-1，时间上表现出“减-增-减-增”的年代际变化，空间上呈南多(强)北少(弱)的分布特征。1980年以来，京津冀地区共出现149次群发性高温过程，主要分布在5—8月，各旬出现次数呈单峰式分布，其中 6 月中旬最多；群发性高温过程的平均持续日数、最大影响范围和综合强度在 44 年间均呈显著增加趋势，而发生频次和平均温度强度则在 21世纪 10年代之后表现出显著增多(强)趋势。44年来京津冀地区综合强度最强的10次群发性高温过程有7次出现在21世纪，其中4次出现在2009年之后，日最高气温的最大值大都出现在河北石家庄地区。空间上，无论在任何年代群发性高温过程所覆盖的范围都主要位于河北中南部地区，其中石家庄东南部和邢台北部是过程高发区的中心地带；20世纪80年代—21世纪10年代，群发性高温过程的高发区不断向北、向东扩展，其中北京中南部、承德南部、天津、唐山大部和秦皇岛西部受群发性高温过程的影响频次存在成倍增加现象，相较其他区域，上述地区高温过程的出现频次表现出更显著的增加趋势。

Abstract:

Based on the daily maximum temperature data from 174 meteorological stations in the Beijing- Tianjin-Hebei region from 1980 to 2023, the present study analyzed the spatial and temporal variations of high-temperature processes. The term cluster high-temperature process (CHTP) was also introduced to further understand these extreme weather events. The results revealed that the average number of high- temperature days per year in the region stood at 10.8, exhibiting a notable upward trend with a climate tendency rate of 1.9 days per decade. Temporally, the pattern of high-temperature days followed a decade- long cycle of“decrease-increase-decrease-increase”, while spatially, the southern regions experienced more frequent and intense heatwaves compared to the northern ones. During the period from 1980 to 2023, a total of 149 CHTPs were recorded in the Beijing-Tianjin-Hebei region, predominantly occurring between May and August. The frequency of these events peaked in mid-June, exhibiting a unimodal distribution. Notably, the average duration, maximum extent of impact, and overall intensity of CHTPs have shown a significant increase over the years, with a particularly sharp rise in frequency and average intensity since 2010. In the past 44 years, seven of the ten strongest CHTPs appeared in the 21st century, and four occurred after 2009; the extreme daily maximum temperature mostly appeared in Shijiazhuang. Spatially, the majority of CHTP occurrences were centered in the central and southern parts of Hebei Province, with Shijiazhuang's southeastern region and Xingtai's northern area identified as high-incidence centers. Over the decades, these high-incidence areas have gradually expanded northward and eastward. Central and southern Beijing, southern Chengde, Tianjin, most of Tangshan, and western Qinhuangdao have witnessed an exponential rise in CHTP frequency, exhibiting a more pronounced increase compared to other regions.