Reflection and diffraction of internal solitary waves by a circular island |
| |
| Authors: | Shenn-Yu Chao Ping-Tung Shaw Ming-Kuang Hsu Ying-Jang Yang |
| |
| Institution: | (1) Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD 21613-0775, USA;(2) Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695-8208, USA;(3) Center for General Education, Northern Taiwan Institute of Science and Technology, Taipei, 112, Taiwan;(4) Department of Marine Science, Chinese Naval Academy, Kaohsiung, 813, Taiwan |
| |
| Abstract: | We have investigated the reflection and diffraction of first-mode and second-mode solitary waves by an island, using a three-dimensional
nonhydrostatic numerical model. The model domain consists of a circular island 15 km in diameter in an ocean 300 m deep. We
use prescribed density anomalies in an initially motionless ocean to produce highly energetic internal solitary waves; their
subsequent propagation is subject to island perturbations with and without the effect of earth’s rotation. In addition to
reflected waves, two wave branches pass around the island and reconnect behind it. Island perturbations to the first-mode
and second-mode waves are qualitatively similar, but the latter is more profound because of the longer contact time and, in
the presence of earth’s rotation, the scale compatibility between Rossby radius of the second baroclinic mode and the island
diameter. Without earth’s rotation, reflected and diffracted waves are symmetrical relative to the longitudinal axis passing
through the island center. With earth’s rotation, the current following the wave front veers to the right due to Coriolis
deflection. For a westward propagating incoming wave, the deflection favors northward wave propagation in the region between
the crossover point and the island, shifting the wave reconnection point behind the island northward. It also displaces the
most visible part of the reflected waves to the southeast. In the presence of earth’s rotation, a second-mode incoming wave
produces island-trapped internal Kelvin waves, which are visible after the passage of the wave front. |
| |
| Keywords: | Internal solitary waves wave impingement on island nonhydrostatic model |
| 本文献已被 SpringerLink 等数据库收录！ |
|
