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

Module ocean_bbc_mod

Contact:  Matthew Harrison ,  S.M. Griffies
Reviewers: 
Change History: WebCVS Log

OVERVIEW

Set bottom boundary conditions

Set bottom boundary conditions

OTHER MODULES USED

    diag_manager_mod
             fms_mod
             mpp_mod
     mpp_domains_mod
ocean_parameters_mod
     ocean_types_mod
   ocean_domains_mod

PUBLIC INTERFACE

ocean_bbc_init:
get_ocean_bbc:

PUBLIC DATA

None.

PUBLIC ROUTINES

  1. ocean_bbc_init

    DESCRIPTION
    Initialize the bottom boundary condition module


  2. get_ocean_bbc

    DESCRIPTION
    Set bottom boundary conditions for velocity and tracer.

    Dimensions of bottom momentum flux are N/m^2 = (kg/m^3)*(m^2/s^2).

    Note the use of rho0 for the conversion from m^2/s^2 to (kg/m^3)*(m^2/s^2). We do not know the precise value of cdbot, so the rho0 approximate value is well within our level of uncertainty. No reason therefore to use in situ rho for this conversion, even when using non-Boussinesq version of mom4.

    Note that bmf needs to be computed on the data domain since the halo values are accessed in ocean_vert_gotm.F90.



NAMELIST

&ocean_bbc_nml

cdbot
Dimensionless coefficient for quadratic bottom drag.
[real, units: dimensionless]
bmf_implicit
For incorporating the bottom momentum drag implicitly in time. This code is fresh and not fully tested. Default is bmf_implicit=.false.
[logical]
cdbot_law_of_wall
For determining bottom drag coefficient using a constant roughness length. Will take maximum between cdbot and the computed value using law of wall log-profile. This option of use when have very very refined vertical resolution (say on order of meters) near the bottom. Terrain following coordinates should use this option since they generally have very refined vertical grid spacing on topography. Default is cdbot_law_of_wall=.false.
[logical]
law_of_wall_rough_length
Bottom roughness length. Default is law_of_wall_rough_length=0.01m, following the default used in the Princeton Ocean Model (POM). This value corresponds to "Law of Wall" physics.
[real, units: metre]
cdbot_roughness_length
For determining bottom drag coefficient using a map of the roughness length. This approach is more relevant for coarse models than the constant roughness length used in the cdbot_law_of_wall option. Default is cdbot_roughness_length=.false.
[logical]
uresidual
Residual bottom velocity due to unresolved fluctuations (e.g., waves and tides) that contribute to bottom dissipation. Should be set to zero when running with explicit representation of tidal forcing and when waves are well resolved. Default is uresidual=.05.
[real, units: m/s]
uvmag_max
Maximum magnitude of the bottom velocity used to compute the bottom momentum drag. Default is uvmag_max=10.0.
[real, units: m/s]
bmf_max
Maximum magnitude of the bottom momentum drag. Default is bmf_max=1.0.
[real, units: N/m2]
debug_this_module
For debugging purposes.
[logical]

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)
  3. S.M. Griffies, 2006: Elements of mom4p1

COMPILER SPECIFICS

None.

PRECOMPILER OPTIONS

None.

LOADER OPTIONS

None.

TEST PROGRAM

None.

KNOWN BUGS

None.

NOTES

None.

FUTURE PLANS

None.

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