Model help:ROMS: Difference between revisions
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a) Momentum balance in the x-directions, respectively | a) Momentum balance in the x-directions, respectively | ||
::::{| | ::::{| | ||
|width=530px|<math> {\frac{\partial u}{\partial t}} + \vec{v} \nabla u - fv = -{\frac{\partial \phi}{\partial x}} + F_{u} + D_{u} </math> | |width=530px|<math> {\frac{\partial u}{\partial t}} + \vec{v} \nabla u - fv = -{\frac{\partial \phi}{\partial x}} - {\frac{\partial}{\partial z}} \left ( \overline{u'w'} - \nu {\frac{\partial u}{\partial z}} \right ) + F_{u} + D_{u} </math> | ||
|width=50p=x align="right"|(1) | |width=50p=x align="right"|(1) | ||
|} | |} | ||
b) Momentum balance in the y-directions, respectively | b) Momentum balance in the y-directions, respectively | ||
::::{| | ::::{| | ||
|width=530px|<math> {\frac{\partial v}{\partial t}} + \vec{v} \nabla | |width=530px|<math> {\frac{\partial v}{\partial t}} + \vec{v} \nabla v + fu = -{\frac{\partial \phi}{\partial y}} - {\frac{\partial}{\partial z}} \left ( \overline{v'w'} - \nu {\frac{\partial v}{\partial z}} \right )+ F_{v} + D_{v} </math> | ||
|width=50p=x align="right"|(2) | |width=50p=x align="right"|(2) | ||
|} | |} | ||
c) Advective-diffusive equations for temperature | c) Advective-diffusive equations for a scalar concentration field C(x,y,z,t) (e.g. salinity, temperature, or nutrients) | ||
::::{| | ::::{| | ||
|width=530px|<math> {\frac{\partial | |width=530px|<math> {\frac{\partial C}{\partial t}} + \vec{v} \nabla C = {\frac{\partial}{\partial z}} \left ( \overline{C'w'} - \nu_{\theta} {\frac{\partial C}{\partial z}} \right )+ F_{C} + D_{C} </math> | ||
|width=50p=x align="right"|(3) | |width=50p=x align="right"|(3) | ||
|} | |} | ||
e) Equation of state | |||
::::{| | ::::{| | ||
|width=530px|<math> | |width=530px|<math> \rho = \rho \left (T,S,P \right ) </math> | ||
|width=50p=x align="right"|(4) | |width=50p=x align="right"|(4) | ||
|} | |} | ||
f) Vertical momentum equation (assume that the vertical pressure gradient balances the buoyancy force) | |||
::::{| | ::::{| | ||
|width=530px|<math> \ | |width=530px|<math> {\frac{\partial \phi}{\partial z}} = {\frac{- \rho g}{\rho_{o}}} </math> | ||
|width=50p=x align="right"|(5) | |width=50p=x align="right"|(5) | ||
|} | |} | ||
g) continuity equation for an incompressible fluid | |||
::::{| | ::::{| | ||
|width=530px|<math> {\frac{\partial | |width=530px|<math> {\frac{\partial u}{\partial x}} + {\frac{\partial v}{\partial y}} + {\frac{\partial w}{\partial z}} = 0 </math> | ||
|width=50p=x align="right"|(6) | |width=50p=x align="right"|(6) | ||
|} | |} | ||
h) Reynolds stresses (an overbar represents a time average and a prime represents a fluctuation above the mean) | |||
::::{| | ::::{| | ||
|width=530px|<math> | |width=530px|<math> \overline{u'w'} = - K_{M} {\frac{\partial u}{\partial z}} </math> | ||
|width=50p=x align="right"|(7) | |width=50p=x align="right"|(7) | ||
|} | |} | ||
::::{| | ::::{| | ||
|width=530px|<math> K_{ | |width=530px|<math> \overline{v'w'} = - K_{M} {\frac{\partial v}{\partial z}} </math> | ||
|width=50p=x align="right"|(8) | |width=50p=x align="right"|(8) | ||
|} | |} | ||
::::{| | ::::{| | ||
|width=530px|<math> K_{ | |width=530px|<math> \overline{C'w'} = - K_{C} {\frac{\partial C}{\partial z}} </math> | ||
|width=50p=x align="right"|(9) | |width=50p=x align="right"|(9) | ||
|} | |} | ||
2) Vertical boundary conditions | |||
a) top boundary condition ( z = ζ (x,y,t )) | |||
::::{| | ::::{| | ||
|width=530px|<math> K_{ | |width=530px|<math> K_{m} {\frac{\partial u}{\partial z}} = \tau_{S}^x \left (x,y,t \right ) </math> | ||
|width=50p=x align="right"|(10) | |width=50p=x align="right"|(10) | ||
|} | |} | ||
::::{| | ::::{| | ||
|width=530px|<math> K_{ | |width=530px|<math> K_{m} {\frac{\partial v}{\partial z}} = \tau_{S}^y \left (x,y,t \right ) </math> | ||
|width=50p=x align="right"|(11) | |width=50p=x align="right"|(11) | ||
|} | |} | ||
::::{| | ::::{| | ||
|width=530px|<math> | |width=530px|<math> K_{C} {\frac{\partial C}{\partial z}} = {\frac{Q_{C}}{\rho_{O} c_{P}}} </math> | ||
|width=50p=x align="right"|(12) | |width=50p=x align="right"|(12) | ||
|} | |} | ||
::::{| | ::::{| | ||
|width=530px|<math> | |width=530px|<math> w = {\frac{\partial \zeta}{\partial t}} </math> | ||
|width=50p=x align="right"|(13) | |width=50p=x align="right"|(13) | ||
|} | |} | ||
b) bottom boundary condition (z = -h(x,y)) | |||
::::{| | ::::{| | ||
|width=530px|<math> K_{m}{\frac{\partial | |width=530px|<math> K_{m}{\frac{\partial u}{\partial z}} = \tau _{b}^x \left (x,y,t \right ) </math> | ||
|width=50p=x align="right"|(14) | |width=50p=x align="right"|(14) | ||
|} | |} | ||
::::{| | ::::{| | ||
|width=530px|<math> K_{ | |width=530px|<math> K_{m}{\frac{\partial v}{\partial z}} = \tau _{b}^y \left (x,y,t \right ) </math> | ||
|width=50p=x align="right"|(15) | |width=50p=x align="right"|(15) | ||
|} | |} | ||
::::{| | ::::{| | ||
|width=530px|<math> K_{ | |width=530px|<math> K_{C}{\frac{\partial C}{\partial z}} = 0 </math> | ||
|width=50p=x align="right"|(16) | |width=50p=x align="right"|(16) | ||
|} | |} | ||
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|width=50p=x align="right"|(17) | |width=50p=x align="right"|(17) | ||
|} | |} | ||
c) Horizontal boundary conditions (Eastern and western boundary)(considering biharmonic friction) | |||
::::{| | ::::{| | ||
|width=530px|<math> \ | |width=530px|<math> {\frac{\partial}{\partial x}} \left ( {\frac{h \nu}{mn}}{\frac{\partial^2 u}{\partial x^2}} \right ) = 0 </math> | ||
|width=50p=x align="right"|(18) | |width=50p=x align="right"|(18) | ||
|} | |} | ||
Horizontal boundary conditions (Northern and southern boundary) | |||
::::{| | ::::{| | ||
|width=530px|<math> \ | |width=530px|<math> {\frac{\partial}{\partial y}} \left ( {\frac{h \nu}{mn}}{\frac{\partial^2 u}{\partial y^2}} \right ) = 0 </math> | ||
|width=50p=x align="right"|(19) | |width=50p=x align="right"|(19) | ||
|} | |} | ||
3) Vertical transformation equations | |||
a) vertical coordinate transformation (been available in ROMS since 1999) | |||
::::{| | ::::{| | ||
|width=530px|<math> | |width=530px|<math> z \left (x,y,\delta, t \right ) = S \left (x,y,\delta \right )+ \zeta \left (x,y,t \right ) [1 + {\frac{S \left (x,y,\delta \right )}{h \left (x,y\right )}}] </math> | ||
|width=50p=x align="right"|(20) | |width=50p=x align="right"|(20) | ||
|} | |} | ||
::::{| | ::::{| | ||
|width=530px|<math> | |width=530px|<math> S \left (x,y,\delta \right ) = h_{c} \delta + [h \left (x,y\right ) - h_{c}] C \left (\delta \right) </math> | ||
|width=50p=x align="right"|(21) | |width=50p=x align="right"|(21) | ||
|} | |} | ||
b) vertical coordinate transformation (been available in ROMS since 2005) | |||
::::{| | |||
|width=530px|<math> z \left (x,y,\delta,t \right ) = \zeta \left (x,y,t\right ) + [\zeta \left (x,y,t\right ) + h \left (x,y \right )] S \left (x,y,\delta \right ) </math> | |||
|width=50p=x align="right"|(22) | |||
|} | |||
::::{| | |||
|width=530px|<math> S \left (x,y,\delta \right ) = {\frac{h_{c} \delta + h \left (x,y \right ) C \left ( \delta \right )}{h_{c} + h \left (x,y\right )}} </math> | |||
|width=50p=x align="right"|(23) | |||
|} | |||
<div class="NavFrame collapsed" style="text-align:left"> | <div class="NavFrame collapsed" style="text-align:left"> | ||
<div class="NavHead">Nomenclature</div> | <div class="NavHead">Nomenclature</div> | ||
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| - | | - | ||
|- | |- | ||
| F<sub>u</sub>,F<sub>v</sub>,F<sub> | | F<sub>u</sub>,F<sub>v</sub>,F<sub>C</sub> | ||
| forcing terms | | forcing terms | ||
| - | | - | ||
|- | |- | ||
| f | | f(x,y) | ||
| coriolis parameter | | coriolis parameter | ||
| - | | - | ||
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| m/s<sup>2</sup> | | m/s<sup>2</sup> | ||
|- | |- | ||
| h | | h(x,y) | ||
| bottom depth | | bottom depth | ||
| m | | m | ||
|- | |- | ||
| ν | | ν,ν<sub>θ</sub> | ||
| | | molecular viscosity and diffusivity | ||
| | | | ||
|- | |- | ||
| K<sub>m</sub>,K<sub> | | K<sub>m</sub>,K<sub>C</sub> | ||
| vertical viscosity and diffusivity | | vertical eddy viscosity and diffusivity | ||
| - | | - | ||
|- | |- | ||
| P | | P | ||
| total pressure, approximately -ρ<sub> | | total pressure, approximately -ρ<sub>o</sub> gz | ||
| | | | ||
|- | |- | ||
| Φ | | Φ(x,y,z,t) | ||
| dynamic pressure, Φ = (P/ρ<sub> | | dynamic pressure, Φ = (P/ρ<sub>o</sub>) | ||
| | | | ||
|- | |- | ||
| ρ + ρ(x,y,z,t) | | ρ<sub>o</sub> + ρ(x,y,z,t) | ||
| total in situ density | | total in situ density | ||
| | | | ||
|- | |- | ||
| S | | S(x,y,z,t) | ||
| salinity | | salinity | ||
| | | | ||
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| | | | ||
|- | |- | ||
| T | | T(x,y,z,t) | ||
| potential temperature | | potential temperature | ||
| | | | ||
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| | | | ||
|- | |- | ||
| ζ | | ζ(x,y,t) | ||
| surface elevation | | surface elevation | ||
| | | | ||
|- | |- | ||
| Q<sub>C</sub> | |||
| surface concentration flux | |||
| Q<sub> | |||
| surface | |||
| - | | - | ||
|- | |- | ||
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| - | | - | ||
|- | |- | ||
| | | S(x,y,δ) | ||
| | | a nonlinear vertical transformation functional (in the vertical transformation equations) | ||
| | |- | ||
|- | |- | ||
| ζ(x,y,t) | |||
| time-varying free-surface(in the vertical transformation equations) | |||
|- | |||
|- | |||
| h(x,y) | |||
| unperturbed water column thickness (in the vertical transformation equations) | |||
|- | |||
|- | |||
| δ | |||
| fractional vertical stretching coordinate (ranging from -1 <= δ <= 0) | |||
|- | |||
|- | |||
| C(δ) | |||
| nondimensional, monotonic, vertical stretching function (ranging from -1 <= C(δ) <= 0) | |||
|- | |||
|- | |||
| h<sub>c</sub> | |||
| a positive thickness controlling the stretching | |||
|- | |||
|- | |||
|} | |} | ||
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==Notes== | ==Notes== | ||
1 In the Boussinesq approximation, density variations are neglected in the momentum equations except in their contribution to the buoyancy force in the vertical momentum equation. | |||
Revision as of 15:48, 25 July 2011
ROMS
ROMS is a community model shared by a large user group around the world, with applications ranging from the study of entire ocean basins to coastal sub-regions.
Model introduction
ROMS incorporates advanced features and high-order numerics, allowing efficient and robust resolution of mesoscale dynamics in the oceanic and coastal domains. The model solves the free surface, hydrostatic, primitive equations of the fluid dynamics over variable topography using stretched; terrain-following coordinates in the vertical and orthogonal, curvilinear coordinates in the horizontal. This allows enhancement of the spatial resolution in the regions of interest.
Model parameters
Uses ports
This will be something that the CSDMS facility will add
Provides ports
This will be something that the CSDMS facility will add
Main equations
1) Equations of motion
a) Momentum balance in the x-directions, respectively
[math]\displaystyle{ {\frac{\partial u}{\partial t}} + \vec{v} \nabla u - fv = -{\frac{\partial \phi}{\partial x}} - {\frac{\partial}{\partial z}} \left ( \overline{u'w'} - \nu {\frac{\partial u}{\partial z}} \right ) + F_{u} + D_{u} }[/math] (1)
b) Momentum balance in the y-directions, respectively
[math]\displaystyle{ {\frac{\partial v}{\partial t}} + \vec{v} \nabla v + fu = -{\frac{\partial \phi}{\partial y}} - {\frac{\partial}{\partial z}} \left ( \overline{v'w'} - \nu {\frac{\partial v}{\partial z}} \right )+ F_{v} + D_{v} }[/math] (2)
c) Advective-diffusive equations for a scalar concentration field C(x,y,z,t) (e.g. salinity, temperature, or nutrients)
[math]\displaystyle{ {\frac{\partial C}{\partial t}} + \vec{v} \nabla C = {\frac{\partial}{\partial z}} \left ( \overline{C'w'} - \nu_{\theta} {\frac{\partial C}{\partial z}} \right )+ F_{C} + D_{C} }[/math] (3)
e) Equation of state
[math]\displaystyle{ \rho = \rho \left (T,S,P \right ) }[/math] (4)
f) Vertical momentum equation (assume that the vertical pressure gradient balances the buoyancy force)
[math]\displaystyle{ {\frac{\partial \phi}{\partial z}} = {\frac{- \rho g}{\rho_{o}}} }[/math] (5)
g) continuity equation for an incompressible fluid
[math]\displaystyle{ {\frac{\partial u}{\partial x}} + {\frac{\partial v}{\partial y}} + {\frac{\partial w}{\partial z}} = 0 }[/math] (6)
h) Reynolds stresses (an overbar represents a time average and a prime represents a fluctuation above the mean)
[math]\displaystyle{ \overline{u'w'} = - K_{M} {\frac{\partial u}{\partial z}} }[/math] (7)
[math]\displaystyle{ \overline{v'w'} = - K_{M} {\frac{\partial v}{\partial z}} }[/math] (8)
[math]\displaystyle{ \overline{C'w'} = - K_{C} {\frac{\partial C}{\partial z}} }[/math] (9)
2) Vertical boundary conditions a) top boundary condition ( z = ζ (x,y,t ))
[math]\displaystyle{ K_{m} {\frac{\partial u}{\partial z}} = \tau_{S}^x \left (x,y,t \right ) }[/math] (10)
[math]\displaystyle{ K_{m} {\frac{\partial v}{\partial z}} = \tau_{S}^y \left (x,y,t \right ) }[/math] (11)
[math]\displaystyle{ K_{C} {\frac{\partial C}{\partial z}} = {\frac{Q_{C}}{\rho_{O} c_{P}}} }[/math] (12)
[math]\displaystyle{ w = {\frac{\partial \zeta}{\partial t}} }[/math] (13)
b) bottom boundary condition (z = -h(x,y))
[math]\displaystyle{ K_{m}{\frac{\partial u}{\partial z}} = \tau _{b}^x \left (x,y,t \right ) }[/math] (14)
[math]\displaystyle{ K_{m}{\frac{\partial v}{\partial z}} = \tau _{b}^y \left (x,y,t \right ) }[/math] (15)
[math]\displaystyle{ K_{C}{\frac{\partial C}{\partial z}} = 0 }[/math] (16)
[math]\displaystyle{ -w + \vec{v} \nabla h = 0 }[/math] (17)
c) Horizontal boundary conditions (Eastern and western boundary)(considering biharmonic friction)
[math]\displaystyle{ {\frac{\partial}{\partial x}} \left ( {\frac{h \nu}{mn}}{\frac{\partial^2 u}{\partial x^2}} \right ) = 0 }[/math] (18)
Horizontal boundary conditions (Northern and southern boundary)
[math]\displaystyle{ {\frac{\partial}{\partial y}} \left ( {\frac{h \nu}{mn}}{\frac{\partial^2 u}{\partial y^2}} \right ) = 0 }[/math] (19)
3) Vertical transformation equations a) vertical coordinate transformation (been available in ROMS since 1999)
[math]\displaystyle{ z \left (x,y,\delta, t \right ) = S \left (x,y,\delta \right )+ \zeta \left (x,y,t \right ) [1 + {\frac{S \left (x,y,\delta \right )}{h \left (x,y\right )}}] }[/math] (20)
[math]\displaystyle{ S \left (x,y,\delta \right ) = h_{c} \delta + [h \left (x,y\right ) - h_{c}] C \left (\delta \right) }[/math] (21)
b) vertical coordinate transformation (been available in ROMS since 2005)
[math]\displaystyle{ z \left (x,y,\delta,t \right ) = \zeta \left (x,y,t\right ) + [\zeta \left (x,y,t\right ) + h \left (x,y \right )] S \left (x,y,\delta \right ) }[/math] (22)
[math]\displaystyle{ S \left (x,y,\delta \right ) = {\frac{h_{c} \delta + h \left (x,y \right ) C \left ( \delta \right )}{h_{c} + h \left (x,y\right )}} }[/math] (23)
Symbol | Description | Unit |
---|---|---|
Du,Dv,DT,DS | diffusive terms | - |
Fu,Fv,FC | forcing terms | - |
f(x,y) | coriolis parameter | - |
g | acceleration of gravity | m/s2 |
h(x,y) | bottom depth | m |
ν,νθ | molecular viscosity and diffusivity | |
Km,KC | vertical eddy viscosity and diffusivity | - |
P | total pressure, approximately -ρo gz | |
Φ(x,y,z,t) | dynamic pressure, Φ = (P/ρo) | |
ρo + ρ(x,y,z,t) | total in situ density | |
S(x,y,z,t) | salinity | |
t | time | |
T(x,y,z,t) | potential temperature | |
u,v,w | the (x,y,z) components of vector velocity | - |
x,y | horizontal coordinate | |
z | vertical coordinate | |
ζ(x,y,t) | surface elevation | |
QC | surface concentration flux | - |
τS x, τS y | surface wind stress | |
τb x, τb y | bottom stress | - |
S(x,y,δ) | a nonlinear vertical transformation functional (in the vertical transformation equations) | |
ζ(x,y,t) | time-varying free-surface(in the vertical transformation equations) | |
h(x,y) | unperturbed water column thickness (in the vertical transformation equations) | |
δ | fractional vertical stretching coordinate (ranging from -1 <= δ <= 0) | |
C(δ) | nondimensional, monotonic, vertical stretching function (ranging from -1 <= C(δ) <= 0) | |
hc | a positive thickness controlling the stretching |
Output
Symbol | Description | Unit |
---|---|---|
qbT | total volume gravel bedload transport rate per unit width summed over all sizes | L2 / T |
τsg * | Shields number based on surface geometric mean size | - |
Dsg | geometric mean size of the surface material | L |
σsg | geometric standard deviations of the surface materials | - |
Dlg | geometric mean size of the bedload | L |
σlg | geometric standard deviation of the bedload | - |
σl | arithmetic standard deviations of bedload materials | - |
σ | arithmetic standard deviations of the surface materials | - |
Dsx | grain size in the surface material, such that x percentage of the material is finer | L |
Dlx | grain size in the bedload material, such that x percentage of the material is finer | L |
σlx | arithmetic standard deviations of bedload materials | L |
Notes
1 In the Boussinesq approximation, density variations are neglected in the momentum equations except in their contribution to the buoyancy force in the vertical momentum equation.
Examples
An example run with input parameters, BLD files, as well as a figure / movie of the output
Follow the next steps to include images / movies of simulations:
- Upload file: http://csdms.colorado.edu/wiki/Special:Upload
- Create link to the file on your page: [[Image:<file name>]].
See also: Help:Images or Help:Movies
Developer(s)
Name of the module developer(s)
References
Key papers
Links
Any link, eg. to the model questionnaire, etc.