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dc.contributor.authorBenthuysen, Jessica
dc.contributor.authorThomas, Leif N.
dc.date.accessioned2013-09-18T11:59:57Z
dc.date.available2013-09-18T11:59:57Z
dc.date.issued2012-09
dc.date.submitted2012-01
dc.identifier.issn0022-3670
dc.identifier.issn1520-0485
dc.identifier.urihttp://hdl.handle.net/1721.1/80780
dc.description.abstractAlthough atmospheric forcing by wind stress or buoyancy flux is known to change the ocean’s potential vorticity (PV) at the surface, less is understood about PV modification in the bottom boundary layer. The adjustment of a geostrophic current over a sloped bottom in a stratified ocean generates PV sources and sinks through friction and diapycnal mixing. The time-dependent problem is solved analytically for a no-slip boundary condition, and scalings are identified for the change in PV that arises during the adjustment to steady state. Numerical experiments are run to test the scalings with different turbulent closure schemes. The key parameters that control whether PV is injected into or extracted from the fluid are the direction of the geostrophic current and the ratio of its initial speed to its steady-state speed. When the current is in the direction of Kelvin wave propagation, downslope Ekman flow advects lighter water under denser water, driving diabatic mixing and extracting PV. For a current in the opposite direction, Ekman advection tends to restratify the bottom boundary layer and increase the PV. Mixing near the bottom counteracts this restratification, however, and an increase in PV will only occur for current speeds exceeding a critical value. Consequently, the change in PV is asymmetric for currents of the opposite sign but the same speed, with a bias toward PV removal. In the limit of a large speed ratio, the change in PV is independent of diapycnal mixing.en_US
dc.description.sponsorshipMassachusetts Institute of Technology. Woods Hole Oceanographic Institution. Joint Programen_US
dc.description.sponsorshipStanford Universityen_US
dc.language.isoen_US
dc.publisherAmerican Meteorological Societyen_US
dc.relation.isversionofhttp://dx.doi.org/10.1175/jpo-d-11-0130.1en_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.sourceAmerican Meteorological Societyen_US
dc.titleFriction and Diapycnal Mixing at a Slope: Boundary Control of Potential Vorticityen_US
dc.typeArticleen_US
dc.identifier.citationBenthuysen, Jessica, and Leif N. Thomas. “Friction and Diapycnal Mixing at a Slope: Boundary Control of Potential Vorticity.” Journal of Physical Oceanography 42, no. 9 (September 2012): 1509-1523. © 2012 American Meteorological Societyen_US
dc.contributor.departmentWoods Hole Oceanographic Institutionen_US
dc.contributor.mitauthorBenthuysen, Jessicaen_US
dc.relation.journalJournal of Physical Oceanographyen_US
dc.eprint.versionFinal published versionen_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsBenthuysen, Jessica; Thomas, Leif N.en_US
mit.licensePUBLISHER_POLICYen_US
mit.metadata.statusComplete


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