| 摘要: |
| 台风"魔蝎"于2018年8月12日夜子时登陆浙江温岭，台风登陆前后造成了浙江近海海水物理特性的诸多变化。台风登陆时的最大风速约为27.5 m/s，登陆时正值天文大潮期间，引起了超过0.30 m的沿岸增水，增水持续了3~4 d。在台风登陆前的7 h内，锚系点水域的海水温度降幅超过1℃。分析表明，海气热交换引起的海水热量损失是锚系点水域温度降低的主要因素，而海水垂向混合带来的海水降温幅度有限。降温在水平区域分布上具有不对称性，台风路径两侧的降温中心呈现明显的不对称性，台风路径右侧的表层海水温度降幅明显强于路径左侧。长江口外至苏南外海水温降幅最为明显，最大降温接近3℃，舟山东南方向海域和温岭东南方向海域最大降温分别超过1.6℃和1.2℃，而在台风路径左侧海域，表层海水温度降幅普遍小于1℃。在台风登陆前的7 h内，海水盐度降低了1.2，研究表明台风带来的强降雨是海水盐度降低的主要因素。本研究，得到了台风"魔蝎"登陆前、登陆时和登陆后，锚系点及周边海域海流、水位、温度、盐度等的变化特征，初步获悉台风期间海水物理特性变化的动力因素，可以为台风影响研究、预防和降低台风带来的风险和损失等提供动力学方面的依据。 |
| 关键词: 浙江沿岸水 台风 风暴潮增水 海表面温度 锚系观测 |
| DOI：10.11759/hykx20191015001 |
| 分类号:P731 |
| 基金项目:浙江省自然科学基金项目（LQ19D060007） |
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| Response of Zhejiang coastal water to typhoon “Yagi” |
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TAO Yu1, ZHONG Wei-fan2, HU Feng-tao1
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1.Zhejiang Ocean Surveying and Mapping Technology Co., Ltd., Hangzhou 310052, China;2.Zhejiang Surveying Institute of Estuary and Coast, Hangzhou 310008, China
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| Abstract: |
| Typhoon "Yagi" landed in Wenling, Zhejiang Province at midnight of August 12, 2018. Before and after landing, it brought many changes in the physical characteristics of the coastal waters of Zhejiang Province. The maximum wind speed of typhoon landing was about 27.5 m/s, and the landing time was during the astronomical spring tide, causing more than 0.30 m coastal water increase, which lasted for 3~4 days. In the 7 hours before typhoon landing, the temperature drop of the sea water at the mooring site was more than 1℃. The heat loss of sea water caused by air-sea heat exchange was the main factor for the decrease of water temperature, while the cooling of sea water caused by vertical mixing was limited. The horizontal distribution of water cooling was asymmetric, and the cooling centers on both sides of the typhoon path were obviously asymmetric. The temperature drop on the right side of the typhoon track was obviously stronger than that on the left side of the track. From the Yangtze River Estuary to the southern Jiangsu sea, the temperature drop was the most obvious, the maximum temperature drop was close to 3℃. The maximum temperature drop in the southeast of Zhoushan Islands and the southeast of Wenling exceeded 1.6℃ and 1.2℃, respectively. while in the left sea area of the typhoon path, the surface water temperature drop was generally less than 1℃. In the 7 hours before typhoon landing, the salinity of sea water decreased by 1.2, the heavy rainfall brought by typhoon was the main factor of the decrease of salinity of sea water. In this study, the variation characteristics of current, water level, temperature and salinity at the mooring site and its surrounding sea area before, during and after landing of Typhoon "Yagi" are obtained, and the dynamic factors of the variation of physical characteristics of sea water during typhoon are preliminarily learned, which can provide dynamic basis for the study of typhoon influence, prevention and reduction of risk and loss caused by typhoon. |
| Key words: Zhejiang coastal water typhoon storm surge water enhancement sea surface temperature mooring observation |
