大气科学2025，Vol.49Issue(3)：645-663,19.DOI:10.3878/j.issn.1006-9895.2405.23135
2023年7月一次华北极端暴雨的多尺度特征
Multiscale Characteristics of An Extreme Rainstorm in North China in July 2023
摘要
Abstract
Herein,the multiscale characteristics of an extreme rainstorm in North China in July 2023 were studied using ERA5 reanalysis and JMA(Japan Meteorological Agency)GSMaP(Global Satellite Mapping of Precipitation)precipitation data with spatial resolutions of 0.25°×0.25°and 0.1°×0.1°,respectively.Results showed that the extreme rainfall episode occurred owing to the combined effect of a monsoon vortex in the Bay of Bengal,a remnant vortex of typhoon Doksuri,typhoon Khanun,high-and low-level jets,a high blocking to the north of North China,and terrain elevations.The configurations of the involved multiscale weather systems were different from those in previous extreme rainstorms.The Bay of Bengal monsoon vortex and typhoon Khanun provided favorable conditions for water vapor transportation during precipitation.The involved high blocking caused water vapor from low latitudes to accumulate east of the Taihang Mountains.Further,the remnant vortex of typhoon Doksuri,situated at the southern foothills of the Taihang Mountains,obtained water vapor.The horizontal potential gradient formed by this vortex,along with the blocking high pressure to its north and the western North Pacific subtropical high to its east,promoted the development and intensification of a low-level jet.The coupling of an 850-hPa low-level jet and 200-hPa high-level jet continuously generated mesoscale convective clouds on the windward slopes of the Taihang Mountains.When ground winds in North China were nearly perpendicular to the involved topography,pronounced forced lifting motion due to topography became organized and developed mesoscale convective clouds,resulting in heavy short-term precipitation.The first stage of intense precipitation occurred when atmospheric stratification was vertically convectively stable.However,the intensified boundary-layer low-level jet promoted inclined upward flow over windward slopes,triggering the release of conditionally symmetric instability energy and leading to heavy precipitation.The second intense precipitation stage mainly occurred in warm sectors with atmospheric stratification showing vertical convective instability triggered by terrain-induced dynamical forcing.关键词
华北极端暴雨/中尺度对流系统/地形/条件性对称不稳定/高低空急流Key words
Extreme rainstorm in North China/Mesoscale convective system/Terrain elevations/Conditional symmetric instability/Upper-and low-level jet分类
天文与地球科学引用本文复制引用
柳龙生,刘璐,李英..2023年7月一次华北极端暴雨的多尺度特征[J].大气科学,2025,49(3):645-663,19.基金项目
国家自然科学基金项目41930972,中国气象局金融气象重点创新团队项目CMA2024ZD03 National Natural Science Foundation of China(Grant 41930972),Key Innovation Team for Financial Meteorology of China Meteorological Administration(Grant CMA2024ZD03) （Grant 41930972）
