江苏暖季短时强降水的时空不均匀特征分析  

Temporal and spatial heterogeneity of warm-season short-time heavy rainfall in Jiangsu Province

作　　者：沈伟 袁慧玲[2,3] 陈曦[2] 王文清 赵燕华[1] SHEN Wei;YUAN Huiling;CHEN Xi;WANG Wenqing;ZHAO Yanhua(Suqian Meteorological Bureau, Suqian 223S00, China;School o f Atmospheric Sciences and Key Laboratory o f Me so sc ale Severe Weather/Ministry o f Education, Nanjing University,Nanjing 210023, China;Jiangsu Collaborative Innovation Center for Climate Change,Nanjing 210023, China)

机构地区：[1]江苏省宿迁市气象局,江苏宿迁223800 [2]南京大学大气科学学院与中尺度灾害性天气教育部重点实验室,江苏南京210023 [3]江苏省气候变化协同创新中心,江苏南京210023

出　　处：《大气科学学报》2017年第4期453-462,共10页Transactions of Atmospheric Sciences

基　　金：国家重点基础研究发展计划(973计划)资助项目(2013CB430106);公益性行业(气象)科研专项(GYHY201206005);江苏省北极阁开放基金(BJG201605);江苏省气象局青年基金科研项目(Q201711);江苏省气象局预报员专项(JSYBY201613)

摘　　要：利用江苏近10 a(2005—2014年)暖季(5—9月)69站逐时降水资料,详细分析了短时强降水的空间分布、年际变化、季节内演变以及日变化特征。分析结果表明:短时强降水空间分布不均,整体上北部比南部活跃,最活跃区均位于沿淮西部,高强度短时强降水多发生在淮北东部,且空间分布集中。近10 a来江苏短时强降水整体呈减少趋势,主要表现为北部地区减少最为显著。短时强降水季节内分布不均匀,以7月最为活跃,高强度短时强降水在8月最为频繁;其逐候分布显示,梅期短时强降水骤增,于7月第2候达到峰值,盛夏期间高强度短时强降水增多,8月第3候达到峰值。江苏短时强降水的日变化整体呈双峰结构,主峰和次峰分别出现在傍晚17时(北京时间,下同)和清晨07时,高强度短时强降水多发于午后;短时强降水日变化存在季节内演变的阶段性特征和地域性差异,其中梅期和盛夏两个高发阶段均呈单峰结构,但梅期峰值出现在清晨,盛夏阶段峰值则出现在傍晚;由南向北,日变化特征由单峰向双峰、多峰演变,在淮河以南地区日峰值大多出现在午后至傍晚,而淮河以北地区多出现在夜间至清晨。Based on hourly precipitation observation data during the warm season(May to September)of2005-2014from69gauge stations in Jiangsu,the spatial and temporal distributions of short-time heavy rainfall(^20m m/h)have been analyzed,which showed obvious heterogeneity in space and time.The occurrence frequency of shorttimeheavy rainfall in northern Jiangsu area was higher than that in the southern region,and its most active regionis located in the western area along Huaihe River.Meanwhile,extreme short-time rainfall events(^50m m/h)frequently occurred in the eastern Huaibei with concentrated rainfall distributions.The occurrence frequency ofshort-time heavy rainfall showed the decreasing trend in the past decade,especially in northern Jiangsu.Ingeneral,July was the most active month of short-time heavy rainfall,and the extreme short-time rainfall events occurredmost frequently in August.The pentad short-time heavy rainfall evolved with the phase variations that thefrequency of short-time heavy rainfall increased rapidly during Meiyu season with the peak in the second pentadof July,and then the frequency of extreme short-time rainfall events increased obviously during mid-summer andreached its peak in the third pentad of August.In average,the diurnal variations of short-time heavy rainfallshowed a double-peak pattern,with the highest peak around17:00BST and the secondary peak around07:00BST,while extreme short-time heavy rainfall events tended to occur in the afternoon.The diurnal variations ofshort-time heavy rainfall also demonstrated obvious sub-seasonal variability and spatial differences.lt had a singlepeak in early morning during Meiyu season and a single peak in the evening during mid-summer.From the southto the north of Jiangsu,the diurnal pattern evolved from a single peak to double and multiple peaks.The peak appearedmostly in the afternoon in the southern area of Huaihe River,while mainly appeared during the night toearly morning in the northern area of Huaihe River.

关 键 词：短时强降水 日变化 时空不均匀 暖季 

分 类 号：P426.6[天文地球—大气科学及气象学]