Geophysical flows under location uncertainty, Part III SQG and frontal dynamics under strong turbulence conditions. Issue 3 (4th May 2017)

• Record Type: Journal Article
• Authors: Resseguier, V.; Mémin, E.; Chapron, B.
• Is Part Of: Geophysical and astrophysical fluid dynamics. Volume 111:Issue 3(2017)
• Page Start: 209
• Page End: 227
• Publication Date: 2017-05-04
• Subjects: Stochastic subgrid tensor -- uncertainty quantification -- upper ocean dynamics; Fluid dynamics -- Periodicals; Astrophysics -- Periodicals; Geophysics -- Periodicals; 551
• DOI: 10.1080/03091929.2017.1312102
• Languages: English
• ISSNs: 0309-1929

Abstract

Abstract : Models under location uncertainty are derived assuming that a component of the velocity is uncorrelated in time. The material derivative is accordingly modified to include an advection correction, inhomogeneous and anisotropic diffusion terms and a multiplicative noise contribution. This change can be consistently applied to all fluid dynamics evolution laws. This paper continues to explore benefits of this framework and consequences of specific scaling assumptions. Starting from a Boussinesq model under location uncertainty, a model is developed to describe a mesoscale flow subject to a strong underlying submesoscale activity. Specifically, turbulent diffusion and rotation effects have similar orders of magnitude. As obtained, the geostrophic balance is modified and the Quasi-Geostrophic assumptions remarkably lead to a zero Potential Vorticity. The ensuing Surface Quasi-Geostrophic model provides a simple diagnosis of warm frontolysis and cold frontogenesis.