近日，中山大学王东海团队研究了2012 - 2021年华南及长江中下游地区持续强降水的环流特征及动力驱动因素。这一研究成果于2025年8月19日发表在《大气科学进展》杂志上。

持续强降雨（PSR）事件，定义为日降水量不少于50在华南和长江中下游流域频繁发生，具有不同的动力机制和湿度条件。基于2012-2021年中国国家气象站逐日降水观测资料和ERA5再分析，研究组分析了SC和MLYRB PSR事件的时空分布及其三维环流动力学。该分析集成了200 hPa波活动通量（WAF）、扰动流函数、500 hPa位势高度、850 hPa风场和综合水汽输送（IVT）的诊断。

结果表明，SC PSR事件主要发生在5 - 6月，降雨中心在粤桂沿海和中部地区；6 ~ 7月为高峰，沿长江中下游呈带状降水。动力学诊断表明，在南海，200 hPa扰动持续的西北-东南传播、500 hPa低压槽的南移和副热带高压的稳定维持为其提供了持续的动力支持。同时，850 hPa强而持久的西南风和持久的水汽输送形成了有利的水汽条件。相反，MLYRB事件的特征是200 hPa流函数异常的快速相变和500 hPa副热带高压的北西扩展，引发强降雨发展。同时，850 hPa西南低气压的突然增强和西南水汽走廊的快速形成保证了充足而及时的水汽供应，促进了PSR的发生。

附：英文原文

Title: Circulation Patterns and Dynamic Drivers of Persistent Severe Rainfall over South China and the Middle-Lower Yangtze River Basin during 2012 to 2021

Author: Yongjia Zhang, Donghai Wang, Lingdong Huang, Enguang Li

Issue&Volume: 2025-08-19

Abstract: Persistent severe rainfall (PSR) events, defined as regional-scale rainfall processes with daily precipitation no less than 50mm for at least three consecutive days, frequently occur over South China (SC) and the Middle-Lower Yangtze River Basin (MLYRB), with distinct dynamic mechanisms and moisture conditions in the two regions. Based on daily precipitation observations from China’s national meteorological stations and ERA5 reanalysis during 2012-2021, this study investigates the spatiotemporal distribution of PSR events in SC and MLYRB and their associated three-dimensional circulation dynamics. The analysis integrates diagnostics of 200 hPa Wave Activity Flux (WAF), perturbation streamfunction, 500 hPa geopotential height, 850 hPa wind fields, and Integrated Water Vapor Transport (IVT). Results show that PSR events in SC mainly occur during May-June, with rainfall centers over coastal and central Guangdong and Guangxi. In contrast, MLYRB events peak during June-July, with a banded rainfall pattern along the middle-lower Yangtze River. Dynamical diagnostics indicate that in SC, sustained northwest-southeast propagation of 200 hPa disturbances, the southward shift of the 500 hPa trough, and steady subtropical high maintenance provide continuous dynamical support. Concurrently, strong and persistent 850 hPa southwesterlies and long-lasting moisture transport form favorable moisture conditions. In contrast, MLYRB events are marked by rapid phase transitions of 200 hPa streamfunction anomalies and northward-westward expansion of the 500 hPa subtropical high, triggering intense rainfall development. Simultaneously, abrupt enhancement of 850 hPa southwesterlies and rapid formation of a southwest moisture corridor ensure abundant and timely moisture supply, facilitating PSR onset.

DOI: 10.1007/s00376-025-5312-x

Source: http://www.iapjournals.ac.cn/aas/article/doi/10.1007/s00376-025-5312-x