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Title

Turbulent mixing due to surface waves indicated by remote sensing of suspended particulate matter and its implementation into coupled modeling of waves, turbulence, and circulation

Author(s)

Pleskachevsky, Andrey;  Dobrynin, Mikhail;  Babanin, Alexander V.;  Guenther, Heinz;  Stanev, Emil

Abstract

This paper studies the impact of the surface waves on the turbulent mixing. The satellite observations of Suspended Particulate Matter (SPM) at ocean surface as an indicator of turbulent quantities of the flow are used. In a water column, SPM builds a vertical profile depending on settling velocities of the particles and on vertical mixing processes, thus SPM is a perfect marker to study the turbulent quantities of the flow. Satellite observations in the North Sea show that surface SPM concentrations, in locations of its deposition, grow rapidly and build plume-shaped, long (many km) uninterrupted and consistent structures during a storm. Also, satellites reveal that SPM rapidly sinks to the seabed after the storm peak has passed and wave height decreases, i.e. with absence of strong turbulence. The non-breaking wave-induced turbulence has been discussed, parameterized and implemented into an equation of evolution of turbulent kinetic energy (TKE) in the frame of mean-flow concept, which can be used in existing circulation models. The ratio between dissipated and total wave energy is used to describe the influence of wave dumping on the mean flow. Our numerical tests reproduce experiments in a wave tank very well and are supported by observations of SPM in the North Sea. Our results show that the motion of an individual non-breaking wave includes turbulent fluctuations if the critical Reynolds number for wave motion is exceeded, independent from presence of currents due to wind or tides. These fluctuations can produce high diffusivity and strongly influences mixing in the upper water layer of the ocean.

Publication type

Journal article

Research centre

Swinburne University of Technology

Source

Journal of Physical Oceanography, Vol. 41, no 4 (Apr 2011), pp. 708-724

Publication year

2011

FOR Code(s)

0405 Oceanography

Keyword(s)

Numerical analysis;  Numerical modelling;  Oceanic waves;  Turbulence

Publisher

American Meteorological Society

ISSN

0022-3670

Publisher URL

http://dx.doi.org/10.1175/2010JPO4328.1

Copyright

Copyright © 2010 American Meteorological Society. The published version of the paper is reproduced here in accordance with the copyright policy of the publisher.

Research Projects

Oceanic conditions within extreme tropical cyclones, Australian Research Council grant number LP0883888

Full text

Peer reviewed