强海况下的波流相互作用研究

发布时间：2018-04-13 07:55

本文选题：波流相互作用 + SWAN-ROMS耦合模型　；参考：《国家海洋环境预报中心》2017年硕士论文

【摘要】：波浪和海流是海洋中最重要也是最常见到的两种海洋动力学过程,它们既相互独立又相互影响、相互作用。波流相互作用对很多海洋现象都有较大的影响,比如风暴潮、裂流、近岸环流、海洋表层温度等。因此研究波-流相互作用对于提高海洋要素的预报水平有重要的现实意义。目前对于近岸波浪破碎带波-流相互作用的研究比较多,但对于强海况下波-流相互作用的相关研究还比较少,缺乏全面的了解。而我国紧邻的西北太平洋海域是世界上受热带气旋影响最多的海区之一,因此调查研究西北太平洋海区在强海况下的波-流相互作用对于准确的预报西北太平洋海区的海况具有重要意义。本文以2016年第1号超强台风“尼伯特”与2016年14号超强台风“莫兰蒂”为背景风场,并分别用SWAN海浪模式、ROMS海洋模式、SWAN-ROMS构建的波流耦合模式模拟在此期间的海洋要素,通过对比分析并结合海洋浮标观测到的实际数据来研究波流相互作用对有效波高、海流、海温的影响。研究表明:波流相互作用对有效波高的影响与波向和表层流向之间的夹角有密切关系:当波向和表层流向大致相同时,波流相互作用使有效波高降低,这主要出现在台风移动路径右侧;当波向与表面流向大致相反时,波流相互作用使有效波高增大;当波向与表层流向之间的夹角越接近90度时,波流相互作用对有效波高的影响越小。同时也发现在远离台风中心的区域,由于海表面流速不大,波流相互作用较弱,对有效波高的影响也较小。整体上在所有区域耦合模式模拟的有效波高更接近实际观测结果,因此在考虑波流相互作用后可以显著提高对有效波高的模拟水平。波流相互作用对海流的影响主要集中出现在近岸以及沿陆架区域,表明地形作用对波致流的影响比较大。考虑波流相互作用可以提高对海表温度的模拟水平。波流相互作用加强了上层海水的垂向混合,在台风发生前后使SST变化幅度增大,这种现象在近岸更为明显;在台风移动路径右侧,由于风向、流向、波向大致相同,诱导更多的下层冷水上翻,因此在此区域低温的范围和程度更大。
[Abstract]:Waves and currents are the two most important and common marine dynamic processes in the ocean. They are independent and interact with each other.Wave and current interactions have great influence on many ocean phenomena, such as storm surge, fissure current, inshore circulation, ocean surface temperature and so on.Therefore, the study of wave-current interaction is of great practical significance in improving the prediction level of ocean elements.At present, there are many researches on wave-current interaction in the near-shore wave breaking zone, but there are few researches on the wave-current interaction in strong sea conditions and lack of comprehensive understanding.The Northwest Pacific Ocean, which is adjacent to China, is one of the most affected areas in the world by tropical cyclones.Therefore, it is important to investigate the wave-current interaction in the Northwest Pacific Ocean under strong sea conditions for the accurate prediction of the sea conditions in the Northwest Pacific Ocean.In this paper, the wind fields of Super strong Typhoon Nibert No. 1 of 2016 and Super Typhoon Morandi of 14 2016 are taken as the background wind field, and the coupled wave-current model constructed by the SWAN wave model / ROMS ocean model / SWAN-ROMS is used to simulate the ocean elements during this period, respectively.The effect of wave current interaction on effective wave height, current and sea surface temperature is studied by comparing and analyzing the actual data observed by ocean buoy.The results show that the influence of wave-current interaction on the effective wave height is closely related to the angle between the wave direction and the surface flow direction: when the wave direction and the surface direction are approximately the same, the effective wave height is reduced by the wave-current interaction.This mainly occurs on the right side of the typhoon's moving path; when the wave direction is approximately opposite to the surface direction, the wave current interaction increases the effective wave height; when the angle between the wave direction and the surface direction is closer to 90 degrees,The effect of wave-current interaction on effective wave height is smaller.At the same time, it is also found that in the region far from the center of typhoon, the interaction of wave and current is weak because of the small velocity of sea surface, and the influence on the effective wave height is also small.As a whole, the simulated effective wave heights in all regions are closer to the actual observed results, so the simulation level of the effective wave heights can be significantly improved by considering the interaction of waves and currents.The effect of wave current interaction on the current mainly occurs in the nearshore and along the continental shelf, indicating that the topographic effect on the wave-induced current is relatively large.Considering the interaction of wave and current, the simulation level of sea surface temperature can be improved.The wave-current interaction strengthens the vertical mixing of the upper sea water and increases the amplitude of SST change before and after the typhoon occurs, which is more obvious in the coastal area, and on the right side of the typhoon's moving path, the wave direction is approximately the same because of the wind direction and the direction of the wind.Induce more lower cold water upturn, so the range and degree of hypothermia in this area is larger.
【学位授予单位】：国家海洋环境预报中心
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P731.2

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