模拟启动时间和双台风对"21.7"河南极端暴雨事件的影响研究OA北大核心CSTPCD

This study utilized the WRF model to conduct ensemble experiments on the Henan record-breaking rainfall event that occurred from July 18th to 21st,2021("21.7"Henan rainfall event),aiming to explore the impact of the simulation start time and typhoons"In-fa"and"Cempaka"on this precipitation event.Analysis of different experimental groups with varying simulated initial times showed that the experiment initiated 24 hours before the peak precipitation occurred could most accurately simulate the path and intensity evolution characteristics of the two typhoons,as well as reproduce the center position,intensity,and temporal evolution characteristics of the"21.7"Henan rainfall event.This is mainly because this experiment well reproduced the low-level southeasterly jet and its dynamic convergence characteristics.Based on this optimal experiment,after removing the typhoon circulation,the subtropical high extended westward and southward,with the water vapor transport path adjusting accordingly.Through quantitative analysis of the vertically integrated water vapor transport in the key precipitation area,it was found that during the time period when the maximum peak of precipitation occurred,typhoons"In-fa"and"Cempaka"weakened the water vapor transport of southeasterly and southerly flows,indicating that the existence of the two typhoons had an uncertain impact on precipitation,and in certain periods,they even reduced the extreme precipitation in Henan region.