Eddy parameterization challenge suite I: Eady spindown

2013 ◽  
Vol 64 ◽  
pp. 12-28 ◽  
Author(s):  
S. Bachman ◽  
B. Fox-Kemper
Keyword(s):  
Eddy Parameterization

scholarly journals The Arctic ocean-ice system studied by contamination modelling

1997 ◽  
Vol 25 ◽  
pp. 17-21 ◽  
Author(s):  
Larissa Nazarenko ◽  
Tessa Sou ◽  
Michael Eby ◽  
Greg Holloway
Keyword(s):  
Fresh Water ◽  
Nuclear Power ◽  
Power Plants ◽  
Ocean Model ◽  
The Arctic ◽  
Good Representation ◽  
Advection Scheme ◽  
Lateral Boundary Conditions ◽  
Eddy Parameterization

The Arctic represents a relatively pristine frontier that is vulnerable to pollution. Substances originating at mid latitudes are transported to the Arctic by atmospheric processes, ocean currents and rivers. These pollutants can accumulate in the Arctic environment. Testing of nuclear weapons, dumping of waste and operation of ships, and nuclear power plants also pose threats.To investigate possible pollutant pathways we used a multi-level primitive-equation ocean model, coupled to a dynamic-thermodynamic sea-ice model. Coupling included conservative transfer of momentum, heat and fresh water. Atmospheric forcing (wind stress, temperature, humidity, radiation and heat fresh-water fluxes) was supplied by datasets or bulk formulae. Open lateral-boundary conditions for the ocean model were supplied either by datasets (temperature and salinity) or from a larger-scale ocean model (momentum). Two integrations were compared — one used a centred-difference advection scheme and viscous damping, while the other used a better representation of an advection scheme and a sub-gridscale eddy parameterization.Tracer simulations showed (1) the importance of good representation of numerical advection, and (2) the role of eddy interacting with sea-floor topography (the neptune effect).

Implications of a new eddy parameterization for ocean models

1996 ◽  
Vol 23 (16) ◽  
pp. 2085-2088 ◽  
Author(s):  
T. J. McDougall ◽  
A. C. Hirst ◽  
M. H. England ◽  
P. C. McIntosh
Keyword(s):  
Ocean Models ◽  
Eddy Parameterization

Transformed Eulerian-Mean Theory. Part II: Potential Vorticity Homogenization and the Equilibrium of a Wind- and Buoyancy-Driven Zonal Flow

2005 ◽  
Vol 35 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Allen Kuo ◽  
R. Alan Plumb ◽  
John Marshall
Keyword(s):  
Potential Vorticity ◽  
Zonal Flow ◽  
Equilibrium Structure ◽  
Surface Fluxes ◽  
Unstable Flow ◽  
Near Surface ◽  
Mixing Rates ◽  
Surface Buoyancy ◽  
Eddy Parameterization ◽  
Transformed Eulerian Mean

Abstract The equilibrium of a modeled wind- and buoyancy-driven, baroclinically unstable, flow is analyzed using the transformed Eulerian-mean (TEM) approach described in Part I. Within the near-adiabatic interior of the flow, Ertel potential vorticity is homogenized along mean isopycnals—a finding readily explained using TEM theory, given the geometry of the domain. The equilibrium, zonal-mean buoyancy structure at the surface is determined entirely by a balance between imposed surface fluxes and residual mean and eddy buoyancy transport within a “surface diabatic layer.” Balance between these same processes and the wind stress determines the stratification, and hence potential vorticity, immediately below this layer. Ertel potential vorticity homogenization below then determines the mean buoyancy structure everywhere. Accordingly, the equilibrium structure of this flow can be described—and quantitatively reproduced—from knowledge of the eddy mixing rates within the surface diabatic zone and the depth of this zone, together with potential vorticity homogenization beneath. These results emphasize the need to include near-surface buoyancy transport, as well as interior PV transport, in eddy parameterization schemes. They also imply that, in more realistic models, the surface buoyancy balances may be impacted by processes in remote locations that allow diapycnal flow.

scholarly journals A Conjecture on the Role of Bottom-Enhanced Diapycnal Mixing in the Parameterization of Geostrophic Eddies

2008 ◽  
Vol 38 (7) ◽  
pp. 1607-1613 ◽  
Author(s):  
David P. Marshall ◽  
Alberto C. Naveira Garabato
Keyword(s):  
Bottom Topography ◽  
Circumstantial Evidence ◽  
Significant Fraction ◽  
Diapycnal Mixing ◽  
Lee Waves ◽  
Ocean Models ◽  
Ultimate Fate ◽  
Eddy Parameterization

Abstract The parameterization of geostrophic eddies represents a large sink of energy in most ocean models, yet the ultimate fate of this eddy energy in the ocean remains unclear. The authors conjecture that a significant fraction of the eddy energy may be transferred to internal lee waves and oscillations over rough bottom topography, leading to bottom-enhanced diapycnal mixing. A range of circumstantial evidence in support of this conjecture is presented and discussed. The authors further propose a modification to the Gent and McWilliams eddy parameterization to account for the bottom-enhanced diapycnal mixing.

scholarly journals Response to Increasing Southern Hemisphere Winds in CCSM4

2011 ◽  
Vol 24 (19) ◽  
pp. 4992-4998 ◽  
Author(s):  
Peter R. Gent ◽  
Gokhan Danabasoglu
Keyword(s):  
Southern Hemisphere ◽  
Variable Coefficient ◽  
Climate Models ◽  
Climate Model ◽  
System Model ◽  
Climate System Model ◽  
Coarse Resolution ◽  
Ocean Response ◽  
Ocean Models ◽  
Eddy Parameterization

Results from two perturbation experiments using the Community Climate System Model version 4 where the Southern Hemisphere zonal wind stress is increased are described. It is shown that the ocean response is in accord with experiments using much-higher-resolution ocean models that do not use an eddy parameterization. The key to obtaining an appropriate response in the coarse-resolution climate model is to specify a variable coefficient in the Gent and McWilliams eddy parameterization, rather than a constant value. This result contrasts with several recent papers that have suggested that coarse-resolution climate models cannot obtain an appropriate response.

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