idealized_hurricane module reference¶

Forcing for the idealized hurricane and SCM_idealized_hurricane examples.

Data Types¶

idealized_hurricane_cs

Container for parameters describing idealized wind structure.

Functions/Subroutines¶

`idealized_hurricane_wind_init()`	Initializes wind profile for the SCM idealized hurricane example.
`idealized_hurricane_wind_forcing()`	Computes the surface wind for the idealized hurricane test cases.
`idealized_hurricane_wind_profile()`	Calculate the wind speed at a location as a function of time.
`simple_wind_scaled_cd()`	This function returns the air-sea drag coefficient using a simple function of the air-sea velocity difference.

Detailed Description¶

Forcing for the idealized hurricane and SCM_idealized_hurricane examples.

Type Documentation¶

type idealized_hurricane/idealized_hurricane_cs¶

Container for parameters describing idealized wind structure.

Type fields:

% rho_a [real] :: Mean air density [R ~> kg m-3].
% pressure_ambient [real] :: Pressure at surface of ambient air [R L2 T-2 ~> Pa].
% pressure_central [real] :: Pressure at surface at hurricane center [R L2 T-2 ~> Pa].
% rad_max_wind [real] :: Radius of maximum winds [L ~> m].
% rad_edge [real] :: Radius of the edge of the hurricane, normalized by the radius of maximum winds [nondim].
% rad_ambient [real] :: Radius at which the winds are at their ambient background values, normalized by the radius of maximum winds [nondim].
% max_windspeed [real] :: Maximum wind speeds [L T-1 ~> m s-1].
% hurr_translation_spd [real] :: Hurricane translation speed [L T-1 ~> m s-1].
% hurr_translation_dir [real] :: Hurricane translation direction [radians].
% gustiness [real] :: Gustiness (used in u*) [R Z2 T-2 ~> Pa].
% rho0 [real] :: A reference ocean density [R ~> kg m-3].
% hurr_cen_y0 [real] :: The initial y position of the hurricane This experiment is conducted in a Cartesian grid and this is assumed to be in meters [L ~> m].
% hurr_cen_x0 [real] :: The initial x position of the hurricane This experiment is conducted in a Cartesian grid and this is assumed to be in meters [L ~> m].
% holland_b [real] :: Parameter ‘B’ from the Holland formula [nondim].
% relative_tau [logical] :: A logical to take difference between wind and surface currents to compute the stress.
% answer_date [integer] :: The vintage of the expressions in the idealized hurricane test case. Values below 20190101 recover the answers from the end of 2018, while higher values use expressions that are rescalable and respect rotational symmetry.
% cd_calm [real] :: The drag coefficient with weak relative winds [nondim].
% calm_speed [real] :: The relative wind speed below which the drag coefficient takes its calm value [L T-1 ~> m s-1].
% cd_windy [real] :: The drag coefficient with strong relative winds [nondim].
% windy_speed [real] :: The relative wind speed below which the drag coefficient takes its windy value [L T-1 ~> m s-1].
% dcd_du10 [real] :: The partial derivative of the drag coefficient times 1000 with the 10 m wind speed for intermediate wind speeds [T L-1 ~> s m-1].
% cd_intercept [real] :: The zero-wind intercept times 1000 of the linear fit for the drag coefficient for the intermediate speeds where there is a linear dependence on the 10 m wind speed [nondim].
% a0_0 [real] :: The zero-radius, zero-speed intercept of the axisymmetric inflow angle [degrees].
% a0_rnorm [real] :: The normalized radius dependence of the axisymmetric inflow angle [degrees].
% a0_speed [real] :: The maximum wind speed dependence of the axisymmetric inflow angle [degrees T L-1 ~> degrees s m-1].
% a1_0 [real] :: The zero-radius, zero-speed intercept of the normalized inflow angle asymmetry [degrees].
% a1_rnorm [real] :: The normalized radius dependence of the normalized inflow angle asymmetry [degrees].
% a1_speed [real] :: The translation speed dependence of the normalized inflow angle asymmetry [degrees T L-1 ~> degrees s m-1].
% p1_0 [real] :: The zero-radius, zero-speed intercept of the angle difference between the translation direction and the inflow direction [degrees].
% p1_rnorm [real] :: The normalized radius dependence of the angle difference between the translation direction and the inflow direction [degrees].
% p1_speed [real] :: The translation speed dependence of the angle difference between the translation direction and the inflow direction [degrees T L-1 ~> degrees s m-1].
% scm_mode [logical] :: If true this being used in Single Column Model mode.
% edge_taper_bug [logical] :: If true and SCM_mode is true, use a bug that does all of the tapering and inflow angle calculations for radii between RAD_EDGE and RAD_AMBIENT as though they were at RAD_EDGE.
% f_column [real] :: Coriolis parameter used in the single column mode idealized hurricane wind profile [T-1 ~> s-1].
% br_bench [logical] :: A “benchmark” configuration (which is meant to provide identical wind to reproduce a previous experiment, where that wind formula contained an error)
% dy_from_center [real] :: (Fixed) distance in y from storm center path [L ~> m]
% pi [real] :: The circumference of a circle divided by its diameter [nondim].
% deg2rad [real] :: The conversion factor from degrees to radians [radian degree-1].

Function/Subroutine Documentation¶

subroutine idealized_hurricane/idealized_hurricane_wind_init(Time, G, US, param_file, CS)¶

Initializes wind profile for the SCM idealized hurricane example.

Parameters:

time :: [in] Model time
g :: [in] Grid structure
us :: [in] A dimensional unit scaling type
param_file :: [in] Input parameter structure
cs :: Parameter container for this module

Call to:

mdl mom_error_handler::mom_error

Called from:

mom_surface_forcing::surface_forcing_init

subroutine idealized_hurricane/idealized_hurricane_wind_forcing(sfc_state, forces, day, G, US, CS)¶

Computes the surface wind for the idealized hurricane test cases.

Parameters:

sfc_state :: [in] Surface state structure
forces :: [inout] A structure with the driving mechanical forces
day :: [in] Time in days
g :: [inout] Grid structure
us :: [in] A dimensional unit scaling type
cs :: Container for idealized hurricane parameters

Call to:

idealized_hurricane_wind_profile mom_error_handler::mom_error

subroutine idealized_hurricane/idealized_hurricane_wind_profile(CS, US, absf, YY, XX, UOCN, VOCN, Tx, Ty)¶

Calculate the wind speed at a location as a function of time.

Parameters:

cs :: Container for idealized hurricane parameters
us :: [in] A dimensional unit scaling type
absf :: [in] Input Coriolis magnitude [T-1 ~> s-1]
yy :: [in] Location in m relative to center y [L ~> m]
xx :: [in] Location in m relative to center x [L ~> m]
uocn :: [in] X surface current [L T-1 ~> m s-1]
vocn :: [in] Y surface current [L T-1 ~> m s-1]
tx :: [out] X stress [R L Z T-2 ~> Pa]
ty :: [out] Y stress [R L Z T-2 ~> Pa]

Call to:

simple_wind_scaled_cd

Called from:

idealized_hurricane_wind_forcing

function idealized_hurricane/simple_wind_scaled_cd(u10, du10, CS) [real]¶

This function returns the air-sea drag coefficient using a simple function of the air-sea velocity difference.

Parameters:

u10 :: [in] The 10 m wind speed [L T-1 ~> m s-1]
du10 :: [in] The magnitude of the difference between the 10 m wind and the ocean flow [L T-1 ~> m s-1]
cs :: Container for SCM parameters

Called from:

idealized_hurricane_wind_profile