What Caused the Differences between the July 2023 and August 1996 Extreme Rainfall Events in North China under Similar Synoptic Background?  

作　　者：Xinghua BAO Jisong SUN Jinfang YIN Xiaoyu GAO Feng LI Xudong LIANG Haodong GU Rudi XIA Mingxin LI Chong WU Jianing FENG 

机构地区：[1]State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,China Meteorological Administration,Beijing 100081 [2]Research Center for Disastrous Weather over Hengduan Mountains&Low-Latitude Plateau,China Meteorological Administration,Kunming 650034 [3]Shigatse National Climatological Observatory,China Meteorological Administration,Shigatse 857000 [4]Tianjin Meteorological Service Centre,Tianjin Meteorological Bureau,Tianjin 300074

出　　处：《Journal of Meteorological Research》2024年第5期861-879,共19页气象学报（英文版）

基　　金：Supported by the National Key Research and Development Program of China(2022YFC3003903);National Natural Science Foundation of China(42030610);Basic Research Fund of Chinese Academy of Meteorological Sciences(2023Z001 and 2023Z020);Development Fund of Chinese Academy of Meteorological Sciences(2023KJ026)。

摘　　要：This study examined the rainfall characteristics and related synoptic processes of two extreme rainfall events that affected North China during 29 July–1 August 2023(“23·7”rainstorm)and 3–5 August 1996(“96·8”rainstorm),respectively.A stable dual-typhoon circulation pattern was observed in both rainstorm events.The surviving vortex of a landed typhoon,slowly approaching the rainstorm region,was blocked by a high-pressure system as it moved northwestward.Meanwhile,the second typhoon over the western Pacific Ocean facilitated remote northward transport of moisture.The low-level jet between the surviving vortex and the western Pacific subtropical high relayed moist warm air from the area of the South China Sea and western Pacific into the rainstorm region.Although the circulation patterns are similar,the stratification conditions,driving factors,and moisture budget of the two rainstorms differed during the main period of rainfall.The“23·7”rainstorm was categorized as warm-sector rainfall,as a result of the lifting of warm moist air over the eastern foothills of Taihang Mountains.In comparison with the situation of the“96·8”rainstorm,the surviving vortex of the“23·7”rainstorm traveled further northeastward and directly impacted the occurrence and progression of the rainfall,leading to relative northward displacement of the rainfall center,while the stronger net inward moisture flux caused greater regional average rainfall.The“96·8”rainstorm was broadly analogous to precipitation of a cold front,and the rainfall center was observed in the convergence area of warm and cold air masses before the mountains;the surviving vortex did not exert direct impact on the rainfall;and the more unstable stratification led to stronger hourly rainfall.The results derived through comparison of the two rainstorms could serve as valuable scientific reference for operational forecasting of heavy rainfall under similar environmental conditions over North China.

关 键 词：“23·7” RAINSTORM “96·8” RAINSTORM extreme rainfall North China dual-typhoon circulation pattern 

分 类 号：P458.121[天文地球—大气科学及气象学]