An assessment of the fine-scale eddies in a high-resolution model of the shelf seas west of Great Britain
Holt, Jason T.; James, Ian D.. 2006 An assessment of the fine-scale eddies in a high-resolution model of the shelf seas west of Great Britain. Ocean Modelling, 13 (3-4). 271-291. 10.1016/j.ocemod.2006.02.005Full text not available from this repository.
High-resolution (∼1.8 km) simulations of the shelf seas west of Great Britain with the Proudman Oceanographic Laboratory Coastal Ocean Modelling System (POLCOMS) demonstrate the formation of an intense field of baroclinic eddies in open stratified waters such as the Celtic Sea. These eddies are most likely to be the result of an inverse energy cascade resulting from tidal flow over rough topography, as demonstrated by a series of idealised model experiments. They are shown to possess many of the properties of eddies identified in idealised laboratory and numerical simulations. Namely, they are predominantly anticyclonic and they merge to increase their size up to a limit set by the internal Rossby radius. An investigation of satellite sea surface temperature observations provides indirect evidence that these model eddies are too energetic, long-lived and frequent. The inclusion of a horizontal diffusion term with a shear dependent diffusivity is shown to significantly reduce the eddy kinetic energy and improve the simulation, without significantly affecting the results in other regions. An optimal parameter value is suggested for this resolution, but the need to put the treatment of horizontal turbulence in such models on a sounder theoretical or empirical footing is identified.
|NORA Subject Terms:||Marine Sciences|
|Date made live:||22 Aug 2012 14:25|
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