Equilibration of a warm pumped lens on a β plane

Abstract. The dynamics of a warm lens created by a surface buoyancy flux and Ekman pumping in an initially homogeneous, unbounded fluid on a β-plane is studied in a set of high resolution numerical experiments. A simple analytical model for the equilibrium structure of the lens is developed which as...

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Bibliographic Details
Main Authors: Timour Radko, John Marshall
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2003
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.549.4487
http://www-paoc.mit.edu/paoc/papers/betalens.pdf
Description
Summary:Abstract. The dynamics of a warm lens created by a surface buoyancy flux and Ekman pumping in an initially homogeneous, unbounded fluid on a β-plane is studied in a set of high resolution numerical experiments. A simple analytical model for the equilibrium structure of the lens is developed which assumes that the input of vorticity and buoyancy from the Ekman layer is balanced through transfer by baroclinic eddies which carry the warm fluid laterally away from the lens. The importance of eddy-induced diapycnal flux in the western intensication region is emphasized by developing a boundary layer theory based entirely on the cross-frontal mass exchange due to eddies. The theory is successfully tested against direct numerical eddy-resolving simulations. Finally, we discuss possible oceanographic implications of the study for understanding subtropical gyres and the Antarctic Circumpolar Current. 1.