On the spurious dissipation of internal waves in ocean circulation models

Callum J. Shakespeare, A. Mc C. Hogg

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Ocean circulation models employ turbulence closure schemes to represent unresolved sub-gridscale processes, and to maintain model stability. Here we investigate solutions that resolve part of the internal wave spectrum, and show that internal waves generated at boundaries of an ocean model spuriously decay as a result of the artificially high horizontal viscosity and diffusivity typically associated with the turbulence closures. We configure a 200m resolution regional-scale model with a near-inviscid and weakly diffusive interior such that spurious decay of the resolved wave field is minimised, and compare with a significantly more viscous and diffusive configuration as used in previous studies. The reduced viscosity and diffusivity results in an order of magnitude increase in the interior wave energy, with waves sourced from both the ocean surface and bottom propagating over the entire depth of the model ocean with negligible dissipation. The results thus point to the need to re-examine turbulence closures and other parameterisations that may conflict with resolved internal wave dynamics.

Original languageEnglish
Title of host publicationProceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2006
PublisherAustralasian Fluid Mechanics Society
ISBN (Electronic)9781740523776
Publication statusPublished - 2016
Event20th Australasian Fluid Mechanics Conference, AFMC 2006 - Perth, Australia
Duration: 5 Dec 20168 Dec 2016

Publication series

NameProceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016

Conference

Conference20th Australasian Fluid Mechanics Conference, AFMC 2006
Country/TerritoryAustralia
CityPerth
Period5/12/168/12/16

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