Evolution of surface gravity waves over a submarine canyon

Magne, R; Belibassakis, KA; Herbers, THC; Ardhuin, F; O'Reilly, WC; Rey, V

dc.contributor.author	Magne, R	en
dc.contributor.author	Belibassakis, KA	en
dc.contributor.author	Herbers, THC	en
dc.contributor.author	Ardhuin, F	en
dc.contributor.author	O'Reilly, WC	en
dc.contributor.author	Rey, V	en
dc.date.accessioned	2014-03-01T01:26:19Z
dc.date.available	2014-03-01T01:26:19Z
dc.date.issued	2007	en
dc.identifier.issn	0148-0227	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18007
dc.subject	Geometric Optics	en
dc.subject	Gravity Wave	en
dc.subject	Surface Wave	en
dc.subject	Three Dimensional	en
dc.subject	Wave Energy	en
dc.subject	Wave Propagation	en
dc.subject	Low Frequency	en
dc.subject	Short Wave	en
dc.subject.classification	Oceanography	en
dc.subject.other	Approximation theory	en
dc.subject.other	Buoys	en
dc.subject.other	Geometrical optics	en
dc.subject.other	Gravity waves	en
dc.subject.other	Mathematical models	en
dc.subject.other	Oceanography	en
dc.subject.other	Spectrum analysis	en
dc.subject.other	Surface waves	en
dc.subject.other	gravity wave	en
dc.subject.other	numerical model	en
dc.subject.other	ocean wave	en
dc.subject.other	submarine canyon	en
dc.subject.other	surface wave	en
dc.subject.other	wave propagation	en
dc.title	Evolution of surface gravity waves over a submarine canyon	en
heal.type	journalArticle	en
heal.identifier.primary	10.1029/2005JC003035	en
heal.identifier.secondary	http://dx.doi.org/10.1029/2005JC003035	en
heal.identifier.secondary	C01002	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	The effects of a submarine canyon on the propagation of ocean surface waves are examined with a three-dimensional coupled-mode model for wave propagation over steep topography. Whereas the classical geometrical optics approximation predicts an abrupt transition from complete transmission at small incidence angles to no transmission at large angles, the full model predicts a more gradual transition with partial reflection/transmission that is sensitive to the canyon geometry and controlled by evanescent modes for small incidence angles and relatively short waves. Model results for large incidence angles are compared with data from directional wave buoys deployed around the rim and over Scripps Canyon, near San Diego, California, during the Nearshore Canyon Experiment (NCEX). Wave heights are observed to decay across the canyon by about a factor 5 over a distance shorter than a wavelength. However, a spectral refraction model predicts an even larger reduction by about a factor 10, because low-frequency components cannot cross the canyon in the geometrical optics approximation. The coupled-mode model yields accurate results over and behind the canyon. These results show that although most of the wave energy is refractively trapped on the offshore rim of the canyon, a small fraction of the wave energy 'tunnels' across the canyon. Simplifications of the model that reduce it to the standard and modified mild slope equations also yield good results, confirming that evanescent modes and high-order bottom slope effects are of minor importance for the energy transformation of waves propagating across depth contours at large oblique angles. Copyright 2007 by the American Geophysical Union.	en
heal.publisher	AMER GEOPHYSICAL UNION	en
heal.journalName	Journal of Geophysical Research C: Oceans	en
dc.identifier.doi	10.1029/2005JC003035	en
dc.identifier.isi	ISI:000243530900001	en
dc.identifier.volume	112	en
dc.identifier.issue	1	en