Non-hydrostatic modelling of regular wave transformation and current circulation in an idealized reef-lagoon-channel system |
| |
Authors: | Jian Shi Wei Liu Jinhai Zheng Chi Zhang Xiangming Cao |
| |
Institution: | 1.Key Laboratory of Ministry of Education for Coastal Disaster and Protection, Hohai University, Nanjing 210024, China2.State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing 210024, China3.College of Harbor, Coastal and Offshore Engineering, Hohai University, Nanjing 210024, China |
| |
Abstract: | The wave-induced setup and circulation in a two dimensional horizontal (2DH) reef-lagoon-channel system is investigated by a non-hydrostatic model. The simulated results agree well with observations from the laboratory experiments, revealing that the model is valid in simulating wave transformation and currents over reefs. The effects of incident wave height, period, and reef flat water depth on the mean sea level and wave-driven currents are examined. Results show that the distributions of mean sea level and current velocities on the reef flat adjacent to the channel vary significantly from those in the area close to the side walls. From the wave averaged current field, an obvious alongshore flux flowing from the reef flat to the channel is captured. The flux from the reef flat composes the second source of the offshore rip current, while the first source is from the lagoon. A detailed momentum balance analysis shows that the alongshore current is mainly induced by the pressure gradient between the reef flat and the channel. In the lagoon, the momentum balances are between the pressure and radiation stress gradient, which drives flow towards the channel. Along the channel, the offshore current is mainly driven by the pressure gradient. |
| |
Keywords: | non-hydrostatic model wave setup wave-induced current coral reef reef-lagoon-channel system |
|
| 点击此处可从《海洋学报(英文版)》浏览原始摘要信息 |
| 点击此处可从《海洋学报(英文版)》下载免费的PDF全文 |
|