大气科学学报2025，Vol.48Issue(1)：122-135,14.DOI:10.13878/j.cnki.dqkxxb.20240719001
云南省区域性短时强降水时空分布及其分类天气系统特征
Spatial and temporal distribution of regional short-term heavy precipitation events in Yunnan Province and classification of weather sys-tem characteristics
摘要
Abstract
The complex topography and unique geographical location of Yunnan Province contribute to the fre-quent occurrence of short-term heavy precipitation,a severe convective weather phenomenon often associated with natural disasters.Using hourly precipitation data at a high spatial resolution of 0.062 5°x0.062 5° from the China Meteorological Administration Land Data Assimilation System(CLDAS)and ERA5 hourly reanalysis data from 2008 to 2022,this study analyzes 91 regional short-term heavy precipitation events and classifies them using K-means clustering.The three-dimensional weather system configuration and its thermal and dynamic characteristics are also examined.The results reveal the following:1)Short-term heavy precipitation is most frequent in south-eastern Yunnan,with the highest intensity observed in southeastern,southwestern,and western region of the prov-ince.Peak intensity occurs between 2000 UTC and 2100 UTC,while peak frequency is observed from 1400 UTC to 1500 UTC.Inter-annual variability is significant,with extreme years experiencing precipitation exceeding 80 mm,compared to an average of 26 mm.2)The precipitation events can be categorized into three types:the west-erly-small trough type,the upper-level long trough type,and the peripheral type of the subtropical high.The upper-level long trough type exhibits the highest intensity and frequency,occurring across the entire province.3)Favorable conditions for precipitation include dynamic,thermal,and moisture-related factors.At 200 hPa,strong divergence is observed in regions such as the southern side of the upper-level jet stream,located in front of a trough or on the western side of the subtropical high,coupled with upward motion at 500 hPa.This is combined with low-level shear lines,low vortices,and surface convergence zones in the middle and lower troposphere.Mois-ture convergence primarily originates from the Bay of Bengal,interacting with westerly airflow over Yunnan Province.The K-index exceeds 38 ℃ in these events.Among the three types,the upper-level long trough type fea-tures the strongest low-level fronts,cold air activity,and mid-and low-level shear lines and vortices centered over Yunnan.Its forward-tilting vertical structure creates strong thermal instability,resulting in enhanced upward mo-tion,significant water vapor convergence across atmospheric layers,and the heaviest precipitation.关键词
云南省/短时强降水/客观分型/天气学模型Key words
Yunnan Province/short-term heavy precipitation/objective classification/synoptic model引用本文复制引用
郭志荣,谭桂容,段玮,杨素雨,姜清华..云南省区域性短时强降水时空分布及其分类天气系统特征[J].大气科学学报,2025,48(1):122-135,14.基金项目
云南省重点研发计划项目(202203AA080010) （202203AA080010）
中国气象局创新发展专项(CXFZ2025J130) （CXFZ2025J130）
国家电网有限公司总部科技项目(5700-202418241A-1-1-ZN) （5700-202418241A-1-1-ZN）
云南省自然科学基金重点项目(202201AS070069) （202201AS070069）
珠江流域(华南区域)气象科研开放基金项目(ZJLY202313) （华南区域）
