华西秋雨时间非均匀性的年代际演变与降水结构变化  

Interdecadal variation of uneven temporal distribution of the"West China autumn rain"and related rain structure changes

作　　者：李玥婕 施晓晖[1] 温敏[1] LI Yuejie;SHI Xiaohui;WEN Min(State Key Laboratory of Severe Weather Meteorological Science and Technology,Chinese Academy of Meteorological Sciences,Beijing 100081,China)

机构地区：[1]灾害天气科学与技术全国重点实验室,中国气象科学研究院,北京100081

出　　处：《气象学报》2025年第2期257-269,共13页Acta Meteorologica Sinica

基　　金：国家自然科学基金重大研究计划重点项目(92158203)、中国气象科学研究院科技发展基金项目(2023KJ040)。

摘　　要：利用1971—2022年华西秋雨监测区335个气象观测站的均一化逐日降水资料及其降水集中指数(Concentration Index,CI),结合华西秋雨区域平均降雨强度、降雨日数及不同强度降雨日数占比等统计结果,采用滑动平均法、气候变化趋势转折判别模型(PLFIM)等,对华西秋雨的降水结构变化及降水非均匀性进行分析。研究结果显示:(1)华西秋雨区大多数站点的多年平均秋雨期CI大于0.6,表明秋雨期降水在时间上分布不均匀。特殊年份及特殊站点的对比分析验证了CI的合理性。(2)近10多年来,华西秋雨的时间非均匀性逐渐增强,其可能的直接原因是近20年来华西秋雨发生了小雨占比减少,大暴雨和极端降水占比增多的降水结构变化,导致降水集中程度增大。In this paper,homogenized daily precipitation data collected at 335 meteorological stations in western China from 1971 to 2022 are used to calculate each station's precipitation Concentration Index(CI).By combining the regionally averaged rainfall intensity,number of rainfall days,and the proportion of different intensity rainfall days with statistical methods such as moving averages and the Piecewise Linear Fitting Model(PLFIM),this study analyzes changes in precipitation structure and uneven distribution of autumn rain of West China.The results are as follows:(1)Most stations in West China have a multi-year average CI exceeding 0.6 during the autumn rain period,suggesting that precipitation is not evenly distributed over time at many stations.Further comparative analysis of specific years and stations supports the validity of CI.(2)Over the past decade,temporal inhomogeneity of autumn rain of West China has been gradually intensifying.The direct possible cause is the shift in precipitation structure over the past 20 years,which is characterized by a decrease in the proportion of light rain and an increase in the proportion of heavy rain and extreme precipitation.The rise in intense rainfall has led to greater precipitation concentration,thereby enhancing the temporal inhomogeneity of precipitation distribution.

关 键 词：华西秋雨 降水集中指数 非均匀性 年代际演变 降水结构变化 

分 类 号：P466[天文地球—大气科学及气象学]