| 摘要: |
| 长江口海域岛屿众多, 地形复杂多变, 对灾害性海浪模拟和预报能力的提升有迫切需求。本研究基于长江口高分辨率非结构网格海浪模式SWAN(Simulating WAve Nearshore), 结合“两洋一海”区域耦合预报系统模拟风场, 以2021年第14号台风“灿都”为例, 研究了台风轨迹、台风移速和台风风场分辨率等对长江口及邻近海域海浪模拟和预报的影响。结果表明: 风场模型水平分辨率增加有利于台风细结构和台风悬臂状结构的模拟。分辨率增加, 风速整体呈减弱趋势, 但在台风中心(小于两倍最大风速半径)和外围悬臂区域风速增加显著。风场分辨率从27 km提升至9 km和3 km, 波浪模拟精度增加显著, 3 km风场驱动的波浪模拟精度最高, 继续提升风场分辨率至1 km对波浪模拟无明显提升。改变风场模型分辨率同时会影响台风路径和移动速度。波浪场的差异反映了台风结构、路径和移动速度的共同影响, 由于波浪的波动传播属性, 台风浪的差异一般比风场差异的范围更大。 |
| 关键词: 台风浪 高分辨率 台风结构 SWAN 长江口 |
| DOI：10.11759/hykx20221129001 |
| 分类号: |
| 基金项目:山东省重点研究发展计划项目(2021CXGC010705) |
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| Influence of high-resolution winds on the simulation of surface waves over the Changjiang River Estuary: a case study of Typhoon Chanthu |
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LI Yi-guo1, RONG Zeng-rui1,2, MENG Xin3, JIANG Yan1, YU Xiao-lin2
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1.College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China;2.Frontier Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266100, China;3.Shanghai Marine Monitoring and Forecasting Center, Shanghai 200062, China
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| Abstract: |
| The Changjiang River Estuary has abundant islands and complex variable topography. The simulation and forecasting of extreme ocean waves need immediate improvement to avoid further economic losses caused by disasters. A high-resolution unstructured simulating wave nearshore model has been developed to study the effects of high-resolution winds on surface wave simulations over the Changjiang River Estuary. Four wind products with resolutions ranging from 27 to 1 km produced by the Asia–Pacific Regional Coupled Prediction System are adopted. Considering typhoon Chanthu 202114 as an example, the effects of wind resolution, typhoon tracking bias, and propagating speed on wave simulations have been examined. Results reveal that finer wind resolution produces more detailed typhoon structures and better-developed inner spiral bands than coarse wind resolution. Comparison between various winds reveals that cases with finer wind resolution increase the wind speed in the central part of typhoons (≤2Rmax) and the outer spiral bands but generally decrease the wind speed in the outer part. Wave simulations adopting different winds suggest that the model skill has been considerably improved when the wind resolution increases from 27 to 3 km, and the simulation run with a 3-km-resolution analysis wind gives the best model–data comparison. Increasing the wind resolution further to 1 km negligibly affects wave improvement. Changing the wind resolutions modifies the wind structure and intensity and alters the typhoon track and propagating rate. Modifications to wave simulations reflect the combined effects of the wind structure, track shifts, and propagating rate. The spatial extension of the difference in typhoon waves is generally larger than that of the difference in winds because the propagating waves translate the distinction to larger areas. |
| Key words: typhoon wave high-resolution typhoon structure SWAN Changjiang River Estuary |
