大气科学学报2023，Vol.46Issue(6)：884-903,20.DOI:10.13878/j.cnki.dqkxxb.20230905001
河北"23.7"极端暴雨过程特征及成因初探
Preliminary study on the characteristics and causes of the"23.7"extreme rainstorm in Hebei
摘要
Abstract
Severe extreme rainstorm events occurred in Hebei Province from July 29 to August 1,2023.The 3-day maximum cumulative precipitation at meteorological observation stations reached 1003.4 mm(Liangji-azhuang,Lincheng,and Xingtai),breaking historical records at many stations in Beijing and Hebei Province.Using observation data,such as high,surface,cloud maps,and Doppler radar,along with ERA5 reanalysis data,this study conducted a preliminary analysis of the extremities and causes of this rainstorm.The results reveal that this extreme rainstorm process resulted from mid-and low-latitude multiscale atmospheric systems involving the high,middle,and low layers of the troposphere,superimposed by topography:(1)The eastward movement of the mid-latitude continental high pressure and the northwestward direction of the western Pacific subtropical high formed a stable northwest-southeast high-pressure dam in northern Hebei.Typhoon"Doksuri"slowed down and stagnated over Henan when blocked by the high-pressure dam,resulting in prolonged typhoon vortex precipitation.(2)The northward movement of water vapor carried by Typhoon"Doksuri"and the southward transport of water vapor by Typhoon"Khanun"on the southern side of the sub-high provided the necessary mois-ture for extreme rainstorms in Hebei.The convergence of the northeast-and southeast-bound jets during the weak-ening of the northern typhoon,combined with the uplifting terrain of Taihang Mountain,formed a strong dynamic mechanism for extreme precipitation.(3)In the middle part of Taihang Mountain,heavy precipitation was con-centrated from the night of July 29th to the night of July 30th,mainly due to the weakening of the spiral rain belt of the typhoon remnant,the uplift of the east-to-northeast jet on the windward slope,and enhanced terrain conver-gence.Heavy precipitation exceeding 250 mm occurred on the windward slope at elevations of 300-800 m in the eastern foothills of Taihang Mountain.(4)In the northern part of Taihang Mountain,the precipitation period was longer,mainly concentrated from the night of July 29th to the night of July 31st,with the larger area experiencing heavy precipitation exceeding 250 mm.This included the windward slope at elevations of 300-600 m in the east-ern foothills of the northern mountain and the adjacent eastern plain.However,the precipitation intensity on the windward slope was lower than in the middle part of Taihang Mountain,while the plain areas experienced higher precipitation intensity.Heavy precipitation in the northern region was primarily caused by the convergence and topographic effects of the northeast and southeast jet streams running parallel to the mountain,with more convec-tive precipitation in the shallow areas and plains on the eastern side of the mountain.(5)The physical fields of water vapor,dynamics,and heat during this precipitation event exhibited strong extremes,with significant devia-tions ranging from 2σ to 6σ.关键词
极端暴雨/中尺度对流系统/台风"杜苏芮"/地形作用Key words
severe extreme rainstorm/mesoscale convective system/typhoon"Doksuri"/terrain effect引用本文复制引用
张江涛,隆璘雪,黄浩杰,何丽华,李江波,张成影,张美如,杨吕玉慈,闫雪瑾,谢祥永,王海川..河北"23.7"极端暴雨过程特征及成因初探[J].大气科学学报,2023,46(6):884-903,20.基金项目
河北省省级科技计划资助项目(20375407D （）
23375401D) （）
中国气象局创新发展专项(CXFZ2023J012) （CXFZ2023J012）
河北省气象局灾害性天气机理创新团队项目 （）
河北省气象局海洋气象要素融合订正技术创新团队项目 （）
河北省气象局暴雨强对流野外观测项目 （）
