 |
| Titel |
Two-dimensional numerical simulations of shoaling internal solitary waves at the ASIAEX site in the South China Sea |
| VerfasserIn |
K. G. Lamb, A. Warn-Varnas |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1023-5809
|
| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 22, no. 3 ; Nr. 22, no. 3 (2015-05-08), S.289-312 |
| Datensatznummer |
250120981
|
| Publikation (Nr.) |
 copernicus.org/npg-22-289-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| The interaction of barotropic tides with Luzon Strait topography generates
some of the world's largest internal solitary waves which eventually shoal
and dissipate on the western side of the northern South China Sea.
Two-dimensional numerical simulations of the shoaling of a single internal
solitary wave at the site of the Asian Seas International Acoustic Experiment
(ASIAEX) have been undertaken in order to investigate the sensitivity of the shoaling
process to the stratification and the underlying bathymetry and to explore
the influence of rotation. The bulk of the simulations are inviscid; however,
exploratory simulations using a vertical eddy-viscosity confined to a near
bottom layer, along with a no-slip boundary condition, suggest that viscous
effects may become important in water shallower than about 200 m. A shoaling
solitary wave fissions into several waves. At depths of 200–300 m the front
of the leading waves become nearly parallel to the bottom and develop a very
steep back as has been observed. The leading waves are followed by waves of
elevation (pedestals) that are conjugate to the waves of depression ahead and
behind them. Horizontal resolutions of at least 50 m are required to
simulate these well. Wave breaking was found to occur behind the second or
third of the leading solitary waves, never at the back of the leading wave.
Comparisons of the shoaling of waves started at depths of 1000 and 3000 m
show significant differences and the shoaling waves can be significantly
non-adiabatic even at depths greater than 2000 m. When waves reach a depth
of 200 m, their amplitudes can be more than 50% larger than the largest
possible solitary wave at that depth. The shoaling behaviour is sensitive to
the presence of small-scale features in the bathymetry: a 200 m high bump at
700 m depth can result in the generation of many mode-two waves and of
higher mode waves. Sensitivity to the stratification is considered by using
three stratifications based on summer observations. They primarily differ in
the depth of the thermocline. The generation of mode-two waves and the
behaviour of the waves in shallow water is sensitive to this depth. Rotation
affects the shoaling waves by reducing the amplitude of the leading waves via
the radiation of long trailing inertia-gravity waves. The
nonlinear-dispersive evolution of these inertia-gravity waves results in the
formation of secondary mode-one wave packets. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|