School of Mathematics and Physics, Qingdao University of Science and Technology, Qingdao 266100, China.
College of Engineering, Ocean University of China, Qingdao 266100, China.
Int J Environ Res Public Health. 2019 Sep 25;16(19):3591. doi: 10.3390/ijerph16193591.
In this study, water levels observed at tide stations in the Bohai Sea, Yellow Sea, and East China Sea during Typhoons 7203 and 8509 were assimilated into a numerical assimilation storm surge model combined with regularization technique to study the wind-stress drag coefficient. The Tikhonov regularization technique with different regularization parameters was tested during the assimilation. Using the regularization technique, the storm surge elevations were successfully simulated in the whole sea areas during Typhoons 7203 and 8509. The storm surge elevations calculated with the regularization technique and the elevations calculated with independent point method were separately compared with the observed data. Comparison results demonstrated that the former was closer to the observed data. The regularization technique had the best performance when the regularization parameter was 100. The spatial distribution of the inverted drag coefficient, storm surge elevations, and the wind fields during both typhoons were presented. Simulated results indicated that the change of drag coefficient is more significant in the coastal regions of the Bohai Sea and north of the Yellow Sea. Further analysis showed that the rising water elevation in the Bohai Sea is mostly attributed to the influence of onshore winds, and the negative storm surge in the South Yellow Sea is mainly caused by offshore winds.
在这项研究中，利用数值同化风暴潮模型，结合正则化技术，同化了 7203 号和 8509 号台风期间渤海、黄海和东海潮位站的观测水位，以研究风应力阻力系数。在同化过程中，测试了不同正则化参数的 Tikhonov 正则化技术。利用正则化技术，成功模拟了 7203 号和 8509 号台风期间整个海域的风暴潮增水。分别将正则化技术计算的风暴潮增水和独立点法计算的风暴潮增水与观测数据进行比较。比较结果表明，前者更接近观测数据。正则化参数为 100 时，正则化技术的性能最佳。给出了两个台风期间反演的阻力系数、风暴潮增水和风场的空间分布。模拟结果表明，在渤海和黄海北部沿海地区，阻力系数的变化更为显著。进一步分析表明，渤海海平面上升主要归因于向岸风的影响，而南黄海的负风暴潮主要是由离岸风引起的。
