Numerical wave modeling in conditions with strong currents: dissipation, refraction and relative wind

Ardhuin, F.; Roland, A.; Dumas, F.; Bennis, A.-C.; Sentchev, A; Forget, P.; Wolf, J. ORCID: https://orcid.org/0000-0003-4129-8221; Girard, F.; Osuna, P.; Benoit, M.. 2012 Numerical wave modeling in conditions with strong currents: dissipation, refraction and relative wind. Journal of Physical Oceanography, 42 (12). 2101-2120. 10.1175/JPO-D-11-0220.1

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Abstract/Summary

Currents effects on waves have led to many developments in numerical wave modeling over the past two decades, from numerical choices to parameterizations. The performance of numerical models in conditions with strong currents is reviewed here, and observed strong effects of opposed currents and modulations of wave heights by tidal currents in several typical situations are interpreted. For current variations on small scales, the rapid steepening of the waves enhances wave breaking. Using different parameterizations with a dissipation rate proportional to some measure of the wave steepness to the fourth power, the results are very different, none being fully satisfactory, which points to the need for more measurements and further refinements of parameterizations. For larger-scale current variations, the observed modifications of the sea state are mostly explained by refraction of waves over currents and relative wind effects, that is, the wind speed relevant for wave generation is the speed in the frame of reference moving with the near-surface current. It is shown that introducing currents in wave models can reduce the errors on significant wave heights by more than 30% in some macrotidal environments, such as the coast of Brittany, in France. This large impact of currents is not confined to the locations where the currents are strongest, but also downwave from strong current gradients.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1175/JPO-D-11-0220.1
Programmes:	NOC Programmes > Marine Systems Modelling
ISSN:	0022-3670
Additional Keywords:	wave modelling
NORA Subject Terms:	Marine Sciences
Date made live:	20 Mar 2013 09:51 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/500550

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1175/JPO-D-11-0220.1

Programmes:

NOC Programmes > Marine Systems Modelling

ISSN:

0022-3670

Additional Keywords:

wave modelling

NORA Subject Terms:

Marine Sciences