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The relation between wave asymmetry and particle orbits analysed by Slepian models

Lindgren, Georg LU orcid and Prevosto, Marc (2021) In Journal of Fluid Mechanics 924.
Abstract
The statistical relation between ocean wave geometry and water particle movements can be formulated in the stochastic Gauss-Lagrange model. In this paper we use Slepian models to obtain detailed information of the sea surface elevation in the neighbourhood of local maxima in a Gaussian wave model and of the movements of the top particle of the waves. We present full conditional distributions of the Gaussian vertical and horizontal movements in the Gauss-Lagrange model, and represent them as one regression component depending on the height and curvature at the wave maxima and one residual component. These conditional distributions define the explicit vertical and horizontal Slepian models. The Slepian models are used to simulate individual... (More)
The statistical relation between ocean wave geometry and water particle movements can be formulated in the stochastic Gauss-Lagrange model. In this paper we use Slepian models to obtain detailed information of the sea surface elevation in the neighbourhood of local maxima in a Gaussian wave model and of the movements of the top particle of the waves. We present full conditional distributions of the Gaussian vertical and horizontal movements in the Gauss-Lagrange model, and represent them as one regression component depending on the height and curvature at the wave maxima and one residual component. These conditional distributions define the explicit vertical and horizontal Slepian models. The Slepian models are used to simulate individual min-max-min waves in space, in particular their front-back asymmetry, and the velocity vector of the particle at the wave maximum. We find that there is a strong relation between the degree of front-back wave asymmetry and the direction of the particle movement. We discuss the role of second-order corrections to the Gaussian components and find only minor effects for the sea states studied. The Slepian model is shown to be an efficient tool to obtain detailed information about Gaussian and related models in the neighbourhood of critical points, without the need for time and space consuming simulations. In particular, they permit easy simulation of shape and kinematics of rare extreme waves. (Less)
Abstract (Swedish)
The statistical relation between ocean wave geometry and water particle movements can be formulated
in the stochastic Gauss-Lagrange model. In this paper we use Slepian models to get detailed
information of the sea surface elevation in the neighbourhood of local maxima in a Gaussian wave model and of the
movements of the top particle of the waves. We present full conditional distributions of the Gaussian
vertical and horizontal movements in the Gauss-Lagrange model, and represent them as
one regression component depending on the height and curvature at the wave maxima and
one residual component. These conditional distributions define the explicit vertical and horizontal Slepian models.

The Slepian... (More)
The statistical relation between ocean wave geometry and water particle movements can be formulated
in the stochastic Gauss-Lagrange model. In this paper we use Slepian models to get detailed
information of the sea surface elevation in the neighbourhood of local maxima in a Gaussian wave model and of the
movements of the top particle of the waves. We present full conditional distributions of the Gaussian
vertical and horizontal movements in the Gauss-Lagrange model, and represent them as
one regression component depending on the height and curvature at the wave maxima and
one residual component. These conditional distributions define the explicit vertical and horizontal Slepian models.

The Slepian models are used to simulate individual min-max-min waves in space,
in particular their front-back asymmetry, and the velocity vector of the particle at the wave maximum. We
find that there is a strong relation between the degree of front-back wave asymmetry and the direction of the particle
movement. We discuss the role of second order corrections to the Gaussian components and find
only minor effects for the sea states studied.

The Slepian model is shown to be an efficient tool to get detailed information about Gaussian and related models
in the neighbourhood of critical points, without the need for time and space consuming
simulations. In particular, they permit easy simulation of shape and kinematics of rare extreme waves. (Less)
Please use this url to cite or link to this publication:
author
and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ocean waves, irregular waves, computational methods, coastal engineering, Lagrange waves, wave asymmetry, particle orbits
in
Journal of Fluid Mechanics
volume
924
article number
A12
pages
27 pages
publisher
Cambridge University Press
external identifiers
  • scopus:85112528084
ISSN
0022-1120
DOI
10.1017/jfm.2021.607
language
English
LU publication?
yes
id
318bc16d-ea74-4005-a0e6-1222fb0d6088
alternative location
https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/relation-between-wave-asymmetry-and-particle-orbits-analysed-by-slepian-models/4BBEEDC465E82410FC5AF0169160F096
date added to LUP
2021-08-05 22:22:25
date last changed
2022-06-21 14:49:44
@article{318bc16d-ea74-4005-a0e6-1222fb0d6088,
  abstract     = {{The statistical relation between ocean wave geometry and water particle movements can be formulated in the stochastic Gauss-Lagrange model. In this paper we use Slepian models to obtain detailed information of the sea surface elevation in the neighbourhood of local maxima in a Gaussian wave model and of the movements of the top particle of the waves. We present full conditional distributions of the Gaussian vertical and horizontal movements in the Gauss-Lagrange model, and represent them as one regression component depending on the height and curvature at the wave maxima and one residual component. These conditional distributions define the explicit vertical and horizontal Slepian models. The Slepian models are used to simulate individual min-max-min waves in space, in particular their front-back asymmetry, and the velocity vector of the particle at the wave maximum. We find that there is a strong relation between the degree of front-back wave asymmetry and the direction of the particle movement. We discuss the role of second-order corrections to the Gaussian components and find only minor effects for the sea states studied. The Slepian model is shown to be an efficient tool to obtain detailed information about Gaussian and related models in the neighbourhood of critical points, without the need for time and space consuming simulations. In particular, they permit easy simulation of shape and kinematics of rare extreme waves.}},
  author       = {{Lindgren, Georg and Prevosto, Marc}},
  issn         = {{0022-1120}},
  keywords     = {{ocean waves; irregular waves; computational methods; coastal engineering; Lagrange waves; wave asymmetry; particle orbits}},
  language     = {{eng}},
  month        = {{10}},
  publisher    = {{Cambridge University Press}},
  series       = {{Journal of Fluid Mechanics}},
  title        = {{The relation between wave asymmetry and particle orbits analysed by Slepian models}},
  url          = {{http://dx.doi.org/10.1017/jfm.2021.607}},
  doi          = {{10.1017/jfm.2021.607}},
  volume       = {{924}},
  year         = {{2021}},
}