太行山精细地形对"23·7"华北极端暴雨特征影响的观测分析
Observational Analysis of Mount Taihang's Orographic Effects on the"23·7"Extreme Precipitation Event in North China
摘要
Abstract
Based on high-resolution multisource observational data,this study analyzed the topographic effects of the Taihang Mountains on the intensity,centers,and convective development characteristics of the"23·7"extreme precipitation event that struck North China.This long-lasting,widely impacting extreme precipitation event,marked by high intensity,was primarily caused by the northward movement of the remnant circulation of Super Typhoon Doksuri,with maximum cumulative precipitation reaching 1003.4 mm.Notably,the area of extreme rainfall and the record-breaking daily precipitation was concentrated on the upwind slope on the eastern side of the Taihang Mountains.The peak cumulative precipitation occurred at the altitude of approximately 400 m,and areas with accumulated precipitation above 600 mm were located within the inner corners of open-valley terrain composed of mesoscale mountains on the eastern slopes.The northern continental high,the western Pacific subtropical high,and the topography of the Taihang Mountains and Shanxi Plateau collectively influenced the slow movement of the typhoon's residual vortex of Doksuri beginning July 29.The Beijing-Tianjin-Hebei region was dominated by convergence induced by the inverted trough on the northern side of the vortex and the topographical blocking effect,forming synoptic uplifting.A low-level easterly jet formed between the typhoon residual vortex and the high-pressure barrier,driving water vapor flux from the boundary layer over the plain up to the slopes of the Taihang Mountains.The convergence center of water vapor flux and subsequent upward movement occurred near 950-925 hPa on the mid-slope,fostering the precipitation peak in that region.The fine terrain of the Taihang Mountains had a significant impact on the occurrence and development of the Mesoscale Convective System(MCS).On the night of July 29,the MCS approaching the upwind slope was significantly enhanced.Under a background of northeast winds in front of the mountain,a convergence center formed on the inner side of the mesoscale trumpet-shaped terrain,producing sustained heavy precipitation.Boundary organization by the cold pool along the eastern edge of the MCS triggered new convection,leading to short-term rainstorms over the piedmont plains.On the night of July 30,another meso-β scale linear MCS developed locally under the influence of a southerly boundary jet and topographic vortex circulation.This system resulted in extreme rainfall intensity exceeding 100 mm h-1.This study advances the scientific understanding of the mechanisms driving extreme precipitation in North China and helps to provide a reference for future forecasting decisions.关键词
极端暴雨/华北/地形/对流Key words
Extreme precipitation/North China/Topography/Convection分类
天文与地球科学引用本文复制引用
李晓兰,陈涛,赵玮,谌芸,符娇兰,许先煌,石岩,沈艳..太行山精细地形对"23·7"华北极端暴雨特征影响的观测分析[J].大气科学,2025,49(3):629-644,16.基金项目
国家重点研发计划2021YFC3000903、2019YFC151040,灾害天气国家重点实验室开放课题 2021LASW-A16,国家自然科学基金项目U2142214,中国气象局复盘总结专项FPZJ2024-159,中国气象局创新发展专项CXFZ2024J025,中国气象局气象能力提升联合研究专项23NLTSZ007,中国气象局暴雨精细化分析和预报青年创新团队专项CMA2023QN05 National Key Research and Development Plan Project(Grant 2021YFC3000903,2019YFC151040),Open Grants of the State Key Laboratory of Severe Weather(Grant 2021LASW-A16),National Natural Science Foundation of China(Grant U2142214),China Meteorological Administration Review and Summary Special Project(Grant FPZJ2024-159),Key Scientific and Technology Research and Development Program of China Meteorological Administration(Grant CXFZ2024J025),Joint Research Project for Meteorological Capacity Improvement(Grant 23NLTSZ007),Special fund of China Meteorological Administration Rainstorm Fine Analysis and Forecast Youth Innovation Team(Grant CMA2023QN05) （Grant 2021YFC3000903,2019YFC151040）
