Accelerating densewater flow down a slope
Huthnance, John M.. 2009 Accelerating densewater flow down a slope. Journal of Physical Oceanography, 39 (6). 14951511. 10.1175/2008JPO3964.1
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Abstract/Summary
Where water is denser on a shallow shelf than in the adjacent deep ocean, it tends to flow down the slope from shelf to ocean. The flow can be in a steady bottom boundary layer for moderate combinations of upslope density gradient ρx∞ and bottom slope (angle θ to horizontal): b ≡ ρx∞ g sinθ / (f**2 ρ0) < 1. Here g is acceleration due to gravity, ρ0 is a mean density and f is twice the component of earth’s rotation normal to the sloping bottom. For stronger combinations of horizontal density gradient and bottom slope, the flow accelerates. Analysis of an idealised initialvalue problem shows that when b ≥ 1 there is a bottom boundary layer with downslope flow, intensifying exponentially at a rate fb**2 (1+b)**1/2 /2, and slowergrowing flow higher up. For stronger stratification b > 2**1/2, i.e. relatively weak Coriolis constraint, the idealised problem posed here may not be the most apposite but suggests that the whole water column accelerates, at a rate [ρ0**1 ρx∞ g sinθ]**1/2 if f is negligible.
Item Type:  Publication  Article 

Digital Object Identifier (DOI):  10.1175/2008JPO3964.1 
Programmes:  POL Programmes > Shallow coastal seas  function and impacts of change Oceans 2025 > Shelf and coastal processes 
ISSN:  00223670 
Additional Keywords:  Boundary layer; gravity current; continental slope; cascade 
NORA Subject Terms:  Marine Sciences Physics 
Date made live:  06 Jul 2009 12:17 
URI:  http://nora.nerc.ac.uk/id/eprint/7240 
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