Tidally driven mixing and dissipation in the stratified boundary layer above steep submarine topography

TitleTidally driven mixing and dissipation in the stratified boundary layer above steep submarine topography
Publication TypeJournal Article
Year of Publication2015
AuthorsWinters KB
JournalGeophysical Research Letters
Volume42
Pagination7123-7130
Date Published2015/09
Type of ArticleArticle
ISBN Number0094-8276
Accession NumberWOS:000363411200032
Keywordsbreaking; deep-ocean; internal bores; sloping boundaries; tides; turbulence; waves
Abstract

A tidally driven, stratified boundary layer over supercritical topography is simulated numerically. The near-boundary flow is characterized by quasiperiodic, bore-like motions and episodic expulsion events where fluid is ejected into the stratified interior. The character of the bores is compared to the high-resolution ocean mooring data of van Haren (2006). The diffusivity of the flow near the boundary is estimated by means of a synthetic dye tracer experiment. The average dissipation rate within the dye cloud is computed and combined with the diffusivity estimate to yield an overall mixing efficiency of 0.15. Both the estimated diffusivity and dissipation rates are in reasonable agreement with the microstructure observations of Kunze et al. (2012) when scaled to the environmental conditions at the Monterey and Soquel Canyons and to the values estimated by van Haren and Gostiaux (2012) above the sloping bottom of the Great Meteor Seamount in the Canary Basin.

DOI10.1002/2015gl064676
Student Publication: 
No