黄、东海海洋对于台风过程的响应

强天气过程下海洋的响应是海洋环境预报的重要内容,它的研究对于防灾减灾、远洋运输、水产养殖等有积极的意义。本文中作者运用一个改进后具有模拟和预报能力的河口海洋模式ECOM-si,引入全强迫条件,对一个真实的强台风下的海洋响应进行了研究。模拟结果表明,海洋对台风过程有强烈的响应,强台风引起SST出现大幅降低,最大达5℃,其中大风抽吸和大风夹卷影响最大;大风引起的平流输送在实际情况中对海水温度、盐度的水平分布有重要影响:台风诱导海水上翻,会使得海洋的混合层明显加深,最大达20—30m;海洋在台风作用下,在上层海洋产生明显的气旋式流场,海面产生的明显下陷可达30cm,台风中心、气旋式流场中心和海面下陷中心三个位并不重合。同时在台风登陆位置附近产生风暴潮,最大增水可达0.8—1.0m,但沿海各地最大增水时间不相同。

RESPONSE OF YELLOW AND EAST CHINA SEAS TO A TYPHOON PROCESS

The ocean response to a severe weather process is an important issue in forecasting ocean weather change, preventing natural disaster, and minimizing losses in marine shipping and aquaculture activities. We proposed an updated 3-D ECOM-si, a dynamic forecast model in coast-ocean region, to simulate the response to a real and fully-forcing typhoon case in the Yellow Sea and East China Sea. Results indicate that the response was intensive. Sea surface temperature (SST) decreased up to 5°C in a large area, which was mostly resulted from the entrainment and pumping. Meanwhile, wind-driven horizontal transport contributed largely to the distributions of real-time temperature and salinity. The typhoon also deepened the oceanic mixed layer by 20 - 30 m. After the typhoon passed by, a cyclonic circulation resulted in ocean surface sink for about 0.3 m with the typhoon movement. In addition, the typhoon generated storm surge up by 0.8 - 1.0 m in maximum increment along the coast nearby landing places; however, the moment of reaching the maximum storm surge elevation were different place to place.