Testing the limits of quasi-geostrophic theory: application to observed laboratory flows outside the quasi-geostrophic regime

Williams, P. D. ORCID: https://orcid.org/0000-0002-9713-9820, Read, P. L. and Haine, T. W. N. (2010) Testing the limits of quasi-geostrophic theory: application to observed laboratory flows outside the quasi-geostrophic regime. Journal Of Fluid Mechanics , 649. pp. 187-203. ISSN 0022-1120 doi: 10.1017/S0022112009993405

Abstract/Summary

We compare laboratory observations of equilibrated baroclinic waves in the rotating two-layer annulus, with numerical simulations from a quasi-geostrophic model. The laboratory experiments lie well outside the quasi-geostrophic regime: the Rossby number reaches unity; the depth-to-width aspect ratio is large; and the fluid contains ageostrophic inertia–gravity waves. Despite being formally inapplicable, the quasi-geostrophic model captures the laboratory flows reasonably well. The model displays several systematic biases, which are consequences of its treatment of boundary layers and neglect of interfacial surface tension and which may be explained without invoking the dynamical effects of the moderate Rossby number, large aspect ratio or inertia–gravity waves. We conclude that quasi-geostrophic theory appears to continue to apply well outside its formal bounds.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/5703
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology Science > School of Mathematical, Physical and Computational Sciences > NCAS
Publisher	Cambridge University Press
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