摘要
2024年我国沿海部分区域发生了两次海水倒灌,引发全国关注。基于实测资料和浪潮耦合数值模型,分析两次海水倒灌事件期间长江口海域风浪潮特征,研究海水倒灌事件成因和机制。结果表明:两次事件均与强北风过境有关,但又显著不同。10月海水倒灌事件前期异常北风占主导,但后期东海出现强东北偏东风,渤黄海罕见的二次增水是北风松弛阶段回荡的开尔文波和东海强东北偏东风过程诱发的陆架强迫波共同作用的结果,二者的贡献占比为42%和58%,受陆架波的影响,此事件期间长江口海域出现两次增水过程。11月海水倒灌事件中北风持续时间更长,空间范围更大,长江口海域出现先增水后减水的特征。今后需要重点关注冷空气松弛阶段的风场变化,特别是异常偏东风过程,为极端突发海水倒灌灾害防御提供新思路。
In 2024,two severe storm surge events occurred along the coasts of the Bohai Sea,Yellow Sea,and South China Sea,leading to coastal flooding in some areas which attracted national attention.Based on in situ observations and the coupled wave-current model,we investigate the spatiotemporal characteristics of winds,surface waves and storm surges around the Changjiang River Estuary,and the involved physical mechanisms of the coastal flooding processes.The results show that both events were associated with strong northerly winds,but with significant difference between them.For the storm surge event during October 19 to 22,the Bohai Sea,Yellow Sea and East China Sea were dominated by northerly winds firstly and experienced high surge from north to south as coastal trapped waves.The East China Sea,however,experienced strong northeasterly winds from east to west during the late period of the event,thus a rare secondary high surge occurred in the Bohai and Yellow Seas,as a result of the combined effect of free Kelvin waves during the relaxation stage of cold air and shelf waves triggered by northeasterly winds in the East China Sea.Numerical simulation shows that the free oscillating Kelvin wave and the forced shelf wave contribute to about 42%and 58%of the secondary high surge,respectively.For the storm surge event during November 16 to 19,the northerly winds lasted a longer time and covered a large area,resulting in surge set-up firstly and then surge set-down over the Changjiang River Estuary.Changes in the wind field during the relaxation phase of cold air,especially the abnormal easterly wind events,are key factors that need to be closely monitored in wave and storm surge forecasts.This study provides new insight into strategy dealing with extreme coastal flooding events in the future.
作者
吴旭云
丁骏
秦涛
WU Xuyun;DING Jun;QIN Tao(Shanghai Ocean Monitoring and Forecasting Center,Shanghai 200062,China)
出处
《海洋预报》
北大核心
2025年第3期34-44,共11页
Marine Forecasts
基金
上海市海洋灾害综合防治体系建设工程项目(沪发改环资[2024]23号)
上海市海洋观测预报共建与服务项目(C2024-123)。
关键词
海水倒灌
风暴潮
陆架波
浪潮耦合模型
长江口海域
seawater backflow
storm surge
shelf wave
wave-current coupled model
Changjiang River Estuary
作者简介
吴旭云(1965-),男,高级工程师,硕士,主要从事海洋监测预报与管理研究。E-mail:gxwj20241122@163.com。
