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On the Numerical Resolution of the Bottom Layer in Simulations of Oceanic Gravity Currents : Volume 7, Issue 2 (04/03/2010)

By Laanaia, N.

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Book Id: WPLBN0003981033
Format Type: PDF Article :
File Size: Pages 28
Reproduction Date: 2015

Title: On the Numerical Resolution of the Bottom Layer in Simulations of Oceanic Gravity Currents : Volume 7, Issue 2 (04/03/2010)  
Author: Laanaia, N.
Volume: Vol. 7, Issue 2
Language: English
Subject: Science, Ocean, Science
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2010
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

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Verron, J., Barnier, B., Laanaia, N., Wirth, A., & Molines, J. M. (2010). On the Numerical Resolution of the Bottom Layer in Simulations of Oceanic Gravity Currents : Volume 7, Issue 2 (04/03/2010). Retrieved from http://www.worldlibrary.net/


Description
Description: LEGI/MEOM/CNRS-INSU, UMR 5519, Grenoble, France. The role of an increased numerical vertical resolution, leading to an explicit resolution of the bottom Ekman layer dynamics, is investigated. Using the hydrostatic ocean model NEMO-OPA9, we demonstrate that the dynamics of an idealised gravity current (on an inclined plane), is well captured when a few (around five) sigma-coordinate levels are added near the ocean floor. Such resolution allows to considerably improve the representation of the descent and transport of the gravity current and the Ekman dynamics near the ocean floor, including the important effect of Ekman veering, which is usually neglected in today's simulations of the ocean dynamics.

Results from high resolution simulations (with σ and z-coordinates) are compared to simulations with a vertical resolution commonly employed in today's ocean models. The latter show a downslope transport that is reduced by almost an order of magnitude and the decrease in the along slope transport is reduced six-fold. We strongly advocate for an increase of the numerical resolution at the ocean floor, similar to the way it is done at the ocean surface and at the lower boundary in atmospheric models.


Summary
On the numerical resolution of the bottom layer in simulations of oceanic gravity currents

Excerpt
Coleman, G. N., Ferziger, J. H., and Spalart, P. R.: A numerical study of the turbulent Ekman layer, J. Fluid. Mech., 213, 313–348, 1990.; Ezer, T. and Weatherly, G. L.: A numerical study of the interaction between a deep cold jet and the bottom boundary layer of the ocean?, J. Phys Oceanogr, 20, 801–816, 1990.; Griffiths, R. W.: Gravity currents in rotating systems, Ann. Rev. Fluid Mech, 18, 59–89, 1986.; Jungclaus, J. H.: A three-dimensional simulation of the formation of anticyclonic lenses (meddies) by the instability of an intermediate depth boundary current, J. Phys. Oceanogr., 29, 1579–98, 1999.; Jungclaus, J. H., Hauser, J., and Käse, R. H.: Cyclogenesis in the Denmark Strait overflow plume, J. Phys. Oceanogr., 31, 3214–3229, 2001.; Killworth, P. D. and Edwards, N. R.: A turbulent bottom boundary layer code for use in numerical ocean models, J. Phys. Oceanogr., 29, 1221–1238, 1999.; Legg, S., Hallberg, R. W., and Girton, J. B.: Comparison of entrainment in overflows simulated by z-coordinate, isopycnal and non-hydrostatic models, Ocean Mod., 11, 69–97, 2006.; Legg, S., Jackson, L., and Hallberg, R. W.: Eddy resolving modeling of overflows, Geophys. Monogr. Ser., 117, 63–81, 2008.; Madec, G.: Nemo ocean Engine, Institut Pierre Simon Laplace (IPSL), France, No. 27, ISSN No 1288-1619, 2008.; Pedlosky, J.: Ocean Circulation Theory, Springer p. 453, ISBN: 3-540-60489-8, 1998.; Whitehead, J. A., Stern, M. E., Flierl G. R., and Klinger B. A.: Experimental observations of baroclinic eddies on a sloping bottom, J. Geophy. Res., 95, 9585–9610, 1990.; Willebrand, J., Barnier, B., Böning, C., Dieterich, C., Killworth, P., Le Provost, C., Jia, Y., Molines, J. M., and New, A. L.: Circulation characteristics in three eddy-permitting models of the North Atlantic, J. Progr. Ocean., 48, 123–162, 2001.; Wirth, A.: A non-hydrostatic flat-bottom ocean model entirely based on Fourier expansion, Ocean Mod., 9, 71–87, 2004.; Wirth, A.: On the basic structure of oceanic gravity currents, Ocean Dynam., 59, 551–563, 2009.; Wirth, A.: Estimation of Friction Parameters in Gravity Currents by Data Assimilation in a Model Hierarchy, Ocean Dynam., submitted, 2010.; Wirth, A. and Sommeria, J.: Gravity current experiments on the Coriolis platform, Technical report EPSHOM, 2007.; Wirth, A. and Verron, J.: Estimation of Friction Parameters and Laws in 1.5-D Shallow-Water Gravity Currents on the f-Plane, by Data Assimilation, Ocean Dynam., 58, 247–257, 2008.

 

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