河北保定市“23·7”强降水过程的观测特征分析  

Analysis of Observation Characteristics of Heavy Rainfall in July 2023 in Baoding,Hebei Province

作　　者：于雷 丁和悦[1,2,3,4] 张会 熊秋芬 YU Lei;DING Heyue;ZHANG Hui;XIONG Qiufen(China Meteorological Administration Xiong’an Atmospheric Boundary Layer Key Laboratory,Xiong’an New Area,Hebei Province 071800;Key Laboratory of Meteorology and Ecological Environment of Hebei Province,Shijiazhuang 050021;Key Laboratory of Intelligent Monitoring and Service on Ecological Meteorology of Baoding,Baoding,Hebei Province 071000;Baoding Meteorological Office,Baoding,Hebei Province 071000;China Meteorological Administration Training Centre,Beijing 100081)

机构地区：[1]中国气象局雄安大气边界层重点开放实验室,河北雄安新区071800 [2]河北省气象与生态环境重点实验室,石家庄050021 [3]保定市生态气象智能监测与服务重点实验室,河北保定071000 [4]保定市气象局,河北保定071000 [5]中国气象局气象干部培训学院,北京100081

出　　处：《气候与环境研究》2024年第4期478-496,共19页Climatic and Environmental Research

基　　金：中国气象局复盘总结专项FPZJ2024-014;河北省省级科技计划23375401D。

摘　　要：利用常规、加密观测资料,风廓线、双偏振雷达探测数据等,对2023年7月29日至8月2日发生在河北省保定市的强致灾性极端强降水过程的阶段性演变、观测特征等进行了分析,结果表明:1)在大陆高压与副高形成“北方高压坝”、台风“杜苏芮”减弱低压北上受阻的环流背景下,“杜苏芮”倒槽、“杜苏芮”残涡东侧的暖式切变线以及副高外围南风气流先后造成保定3个阶段的降水,最长单站降水持续时间70 h,7月30日07:00(北京时间,下同)至8月1日03:00涿州上游、海拔高度介于0.1~1 km的浅山区内不断出现短时强降水、“列车效应”显著,导致该区域出现极端的洪灾。2)29日倒槽降水雨带呈东北—西南向并随时间西北移,最大降水强度39.4 mm/h;30日副高西移,倒槽东侧位势梯度加大,同时台风“卡努”北侧东南气流并入,冀鲁地区低空东南急流加强、北伸,雨带呈“人”字形,降水落区无变化但短时强降水频次增大、强降水范围集中,雨强增至82.2 mm/h。3)切变线降水阶段,对流不稳定层增厚,降水主要集中在西南风—东南风切变线与南风—东风切变线之间,多局地短时强降水,最大雨强为76.3 mm/h。4)“杜苏芮”影响结束后,副高外围的低层偏南气流有明显的风速辐合,引发暖区局地降水,雨带呈准南北向且分为多轮次,各轮次降水落区次第向东移动且强度不断减小,阶段内最大降水强度54.2 mm/h。5)双偏振雷达图像显示,在倒槽降水阶段,前期为低质心暖云降水,对流发展高度最低,暖云碰并机制明显,雨滴粒子直径最大;“卡努”东南急流并入时段,0°C层下降、-10°C层抬升,对流高度增加,霰粒子增长、冰相粒子聚合融化,雨滴粒子浓度增至最大。在切变线降水时0~-10°C层厚度减小而-10~-20°C层厚度增加,对流发展高度最高,霰粒子凇附增长更为明显。6)地形对降水有增幅作用,倒槽降水阶段东南The extremely heavy rainfall that occurred in Baoding,Hebei Province from 29 Jul to 2 Aug 2023 was examined by using conventional and hourly observation data,wind profiles,and dual polarization radar detection data.The results showed the following:1)Under the combined influence of a northern high-pressure dam by continental high pressure and subtropical high pressure,the inverted trough of weakening typhoon Doksuri,a warm shear line on the east side of Doksuri,and the southerly airflow of the subtropical high,Baoding experience three stages of precipitation,with the longest stage lasting 70 h.From 0700 LST 30 Jul to 0300 LST 1 Aug,continuous short-term heavy precipitation occurred owing to the“train effect”in the shallow mountainous area upstream of Zhuozhou,with altitudes between 0.1–1 km,leading to severe local flooding.2)The rain belt evolution on 29 Jul showed a northeast–southwest orientation,moving northwest over time,with precipitation intensity below 40 mm/h.The subtropical high shifted westward,increasing the potential gradient on the east side of the inverted trough on 30 Jul.Concurrently,the southeast airflow on the north side of typhoon Khanun merged with the low-level southeast jet in the Hebei and Shandong region,strengthening and extending northward.The rain belt formed a herringbone shape,maintaining its area while the frequency and intensity of short-term heavy rainfall within the area increased,reaching an intensity of 82.2 mm/h.3)During the shear line precipitation stage,the convective instability layer thickened,with precipitation primarily concentrating between the SW–SE and S–E shear lines.This stage saw numerous instances of short-term heavy rainfalls locally,with a maximum rainfall intensity of 76.3 mm/h.4)After the impact of Doksuri,significant convergence of wind speed in the low-level southerly airflow west of the subtropical high led to local precipitation in the warm area.The rain belt exhibited a quasi north–south direction and was divided into multiple rounds,each movi

关 键 词：台风“杜苏芮” 强降水 双偏振雷达 观测特征 地形影响 

分 类 号：P458[天文地球—大气科学及气象学]