《海洋预报》| 渤海西岸一次突发性大暴雨触发机制分析

摘要：基于ERA5再分析数据、HRCLDAS多源融合实况数据、卫星和常规观测资料，结合双多普勒雷达反演技术，深入研究了2024年8月4日副热带高压外围突发性暴雨的触发机制及预报偏差成因。结果表明：此次暴雨过程中沧州东、西部降雨的显著差异，主要归因于水汽和动力条件精细结构的不同。降雨分为两个阶段，第一阶段降水与700～1 500 m高度西南气流中的脉动辐合相关，超低空急流跃增促使渤海西岸对流强烈发展；第二阶段强降水由海上雷暴冷池的偏东风出流与西南风之间的辐合线触发，中尺度辐合线的维持和加强是对流单体新生和发展的关键因素。双多普勒雷达三维风场精细化反演揭示了中尺度系统高低层垂直耦合机制。

关键词：副热带高压 局地大暴雨 中尺度对流系统 触发 

Abstract：Based on the ERA5 reanalysis data, the HRCLDAS multi-source fused observational data, satellite and conventional observational materials, an in-depth study in combination with dual-Doppler radar retrieval techniques is conducted on the triggering mechanisms and causes of forecast deviations of a sudden heavy rainfall event that occurred on the periphery of the subtropical high on August 4, 2024. The results show that the notable differences in rainfall between the eastern and western parts of Cangzhou are primarily attributed to the distinct fine-scale structures of moisture and dynamic conditions. The rainfall process can be divided into two stages. The first stage is associated with pulsating convergence within the southwesterly airflow at heights ranging from 700 m to 1 500 m. The sudden surge of an ultra-low-level jet promotes the vigorous development of convection along the western coast of the Bohai Sea. The second stage of intense precipitation is triggered by the convergence line formed between the easterly outflow from a maritime thunderstorm cold pool and the southwesterly winds. The maintenance and intensification of the mesoscale convergence line are key factors in the initiation and development of convective cells. The fine-scale three-dimensional wind field retrieval by dualDoppler radar unveils the vertical coupling mechanism between the upper and lower levels of the mesoscale system.

Key words：subtropical high; local severe rainstorm; mesoscale convective system; triggering

读者也可以通过公众号菜单栏

“相关知识”板块进入《当期目录》和《过刊浏览》

查阅详细期刊内容

未来两天海洋环境预报

35个美丽海岛环境预报