user_change_diffusivity module reference¶

Increments the diapycnal diffusivity in a specified band of latitudes and densities.

Data Types¶

user_change_diff_cs

Control structure for user_change_diffusivity().

Functions/Subroutines¶

`user_change_diff()`	This subroutine provides an interface for a user to use to modify the main code to alter the diffusivities as needed.
`range_ok()`	This subroutine checks whether the 4 values of range are in ascending order.
`val_weights()`	This subroutine returns a value that goes smoothly from 0 to 1, stays at 1, and then goes smoothly back to 0 at the four values of range.
`user_change_diff_init()`	Set up the module control structure.
`user_change_diff_end()`	Clean up the module control structure.

Detailed Description¶

Increments the diapycnal diffusivity in a specified band of latitudes and densities.

Type Documentation¶

type user_change_diffusivity/user_change_diff_cs¶

Control structure for user_change_diffusivity(). .

Type fields:

% initialized [logical] :: True if this control structure has been initialized.
% kd_add [real] :: The scale of a diffusivity that is added everywhere without any filtering or scaling [H Z T-1 ~> m2 s-1 or kg m-1 s-1].
% lat_range [real(4)] :: 4 values that define the latitude range over which a diffusivity scaled by Kd_add is added [degrees_N].
% rho_range [real(4)] :: 4 values that define the coordinate potential density range over which a diffusivity scaled by Kd_add is added [R ~> kg m-3].
% use_abs_lat [logical] :: If true, use the absolute value of latitude when setting lat_range.
% diag [type( diag_ctrl ),pointer] :: A structure that is used to regulate the timing of diagnostic output.

Function/Subroutine Documentation¶

subroutine user_change_diffusivity/user_change_diff(h, tv, G, GV, US, CS, Kd_lay, Kd_int, T_f, S_f, Kd_int_add)¶

This subroutine provides an interface for a user to use to modify the main code to alter the diffusivities as needed. The specific example implemented here augments the diffusivity for a specified range of latitude and coordinate potential density.

Parameters:

g :: [in] The ocean’s grid structure.
gv :: [in] The ocean’s vertical grid structure
h :: [in] Layer thickness [H ~> m or kg m-2].
tv :: [in] A structure containing pointers to any available thermodynamic fields. Absent fields have NULL ptrs.
us :: [in] A dimensional unit scaling type
cs :: This module’s control structure.
kd_lay :: [inout] The diapycnal diffusivity of each layer [H Z T-1 ~> m2 s-1 or kg m-1 s-1]
kd_int :: [inout] The diapycnal diffusivity at each interface [H Z T-1 ~> m2 s-1 or kg m-1 s-1]
t_f :: [in] Temperature with massless layers filled in vertically [C ~> degC].
s_f :: [in] Salinity with massless layers filled in vertically [S ~> ppt].
kd_int_add :: The diapycnal diffusivity that is being added at each interface [H Z T-1 ~> m2 s-1 or kg m-1 s-1]

Call to:

mom_eos::eos_domain mom_error_handler::mom_error range_ok val_weights

function user_change_diffusivity/range_ok(range) [logical]¶

This subroutine checks whether the 4 values of range are in ascending order.

Parameters:: range :: [in] Four values to check [arbitrary]
Return:: undefined :: Return value.
Called from:: user_change_diff user_change_diff_init

function user_change_diffusivity/val_weights(val, range) [real]¶

This subroutine returns a value that goes smoothly from 0 to 1, stays at 1, and then goes smoothly back to 0 at the four values of range. The transitions are cubic, and have zero first derivatives where the curves hit 0 and 1. The values in range must be in ascending order, as can be checked by calling range_OK.

Parameters:

val :: [in] Value for which we need an answer [arbitrary units].
range :: [in] Range over which the answer is non-zero [arbitrary units].

Return:

undefined :: Return value [nondim].

Called from:

user_change_diff

subroutine user_change_diffusivity/user_change_diff_init(Time, G, GV, US, param_file, diag, CS)¶

Set up the module control structure.

Parameters:

time :: [in] The current model time.
g :: [in] The ocean’s grid structure.
gv :: [in] The ocean’s vertical grid structure
us :: [in] A dimensional unit scaling type
param_file :: [in] A structure indicating the open file to parse for model parameter values.
diag :: [inout] A structure that is used to regulate diagnostic output.
cs :: A pointer that is set to point to the control structure for this module.

Call to:

mom_error_handler::mom_error range_ok

subroutine user_change_diffusivity/user_change_diff_end(CS)¶

Clean up the module control structure.

Parameters:: cs :: A pointer that is set to point to the control structure for this module.
Called from:: mom_set_diffusivity::set_diffusivity_end