A parameterization of the passive layer of a quasigeostrophic flow in a continuously-stratified ocean. (May 2018)

• Record Type: Journal Article
• Authors: Benilov, E.S.
• Is Part Of: Ocean modelling. Volume 125(2018)
• Page Start: 39
• Page End: 44
• Publication Date: 2018-05
• Subjects: Mesoscale flows -- Quasigeostrophic approximation -- Stratification; Oceanography -- Periodicals; Océanographie -- Périodiques; Oceanography; Periodicals; 551.46
• DOI: 10.1016/j.ocemod.2018.03.003
• Languages: English
• ISSNs: 1463-5003

Abstract

Highlights: A model is developed describing the response of the oceans weakly-stratified lower layer to a flow in the upper layer. The model is tested for the problem of baroclinic instability of a plain continuously-stratified flow. The model saves 50–70% of resources when simulating mesoscale flows. Abstract: This paper examines quasigeostrophic flows in an ocean that can be subdivided into an upper active layer (AL) and a lower passive layer (PL), with the flow and density stratification mainly confined to the former. Under this assumption, an asymptotic model is derived parameterizing the effect of the PL on the AL. The model depends only on the PL's depth, whereas its Väisälä–Brunt frequency turns out to be unimportant (as long as it is small). Under an additional assumption—that the potential vorticity field in the PL is well-diffused and, thus, uniform—the derived model reduces to a simple boundary condition. This condition is to be applied at the AL/PL interface, after which the PL can be excluded from consideration.