PUBLIC INTERFACE ~ PUBLIC DATA ~ PUBLIC ROUTINES ~ NAMELIST ~ DIAGNOSTIC FIELDS ~ ERROR MESSAGES ~ REFERENCES ~ NOTES

Module ocean_advection_velocity_mod

Contact:  R.C. Pacanowski S.M. Griffies
Reviewers: 
Change History: WebCVS Log


OVERVIEW

Advection velocity components for tracer and momenta transport

The module computes the horizontal and vertical components to the advection velocity on the face of tracer and velocity cells. The three components are related by continuity. The horizontal components to the advection velocity are thickness weighted. Some diagnostics related to volume transport classified according to both depth and density classes are also computed.


OTHER MODULES USED

     axis_utils_mod
constants_mod
diag_manager_mod
fms_mod
mpp_domains_mod
mpp_mod
ocean_domains_mod
ocean_operators_mod
ocean_types_mod
ocean_workspace_mod
ocean_obc_mod

PUBLIC INTERFACE

ocean_advection_velocity_init:
ocean_advection_velocity:


PUBLIC DATA

None.


PUBLIC ROUTINES

  1. ocean_advection_velocity_init

    DESCRIPTION
    Initialize the advection velocity module


  2. ocean_advection_velocity

    DESCRIPTION
    Compute thickness weighted advection velocities normal to side faces of U-cells and T-cells on a b-grid. Also compute vertical advection velocity normal to bottom faces of U-cells and T-cells.



NAMELIST

&ocean_advection_velocity_nml

max_advection_velocity
This is a check value used to determine if the time steps will result in linearly stable advection. If set to a number < 0, then model will estimate the value as a function of maximum grid size. Note that this time step check is not rigorous, and it depends on the details of the advection scheme. Nonetheless, it provides some useful warning for setting the time steps in the model.
[real, units: meter/sec]


DATA SETS

None.


ERROR MESSAGES

None.


REFERENCES

  1. R.C. Pacanowski and S.M. Griffies The MOM3 Manual (1999)
  2. S.M. Griffies, M.J. Harrison, R.C. Pacanowski, and A. Rosati A Technical Guide to MOM4 (2003)


COMPILER SPECIFICS

None.


PRECOMPILER OPTIONS

None.


LOADER OPTIONS

None.


TEST PROGRAM

None.


KNOWN BUGS

None.


NOTES

The expressions for the horizontal components for tracer advection allow for a proper conversion between pressure work and buoyancy.

The remapping operators are derived from considerations of linear interpolation and volume conservation. A "remapping error" is computed to determine the consistency between the tracer and velocity grid advection velocities. This error is roundoff only for cases where the horizontal tracer and velocity grids are linearly related, as is the case for the spherical coordinate version of mom4. The tripolar version of mom4 does not have tracer and velocity grids related linearly, and so the "remapping error" is nontrivial. The significance of this error is unclear. No adverse effects have been identified.

The vertical velocity components for both the tracer and velocity cells are diagnosed via continuity (either volume or mass conservation depending on the use of the Boussinesq or non-Boussinesq versions of mom4).


FUTURE PLANS

None.


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