namespace mom_eos_linear

Overview

A simple linear equation of state for sea water with constant coefficients. More…

namespace mom_eos_linear {

// interfaces

interface calculate_density_derivs_linear;
interface calculate_density_linear;
interface calculate_density_second_derivs_linear;
interface calculate_spec_vol_linear;

// global functions

subroutine, public calculate_density_scalar_linear(
    T T,
    S S,
    pressure pressure,
    rho rho,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS,
    rho_ref rho_ref
    );

subroutine, public calculate_density_array_linear(
    T T,
    S S,
    pressure pressure,
    rho rho,
    start start,
    npts npts,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS,
    rho_ref rho_ref
    );

subroutine, public calculate_density_derivs_scalar_linear(
    T T,
    S S,
    pressure pressure,
    drho_dT_out drho_dT_out,
    drho_dS_out drho_dS_out,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS
    );

subroutine, public calculate_specvol_derivs_linear(
    T T,
    S S,
    pressure pressure,
    dSV_dT dSV_dT,
    dSV_dS dSV_dS,
    start start,
    npts npts,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS
    );

subroutine, public calculate_compress_linear(
    T T,
    S S,
    pressure pressure,
    rho rho,
    drho_dp drho_dp,
    start start,
    npts npts,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS
    );

subroutine, public int_density_dz_linear(
    T T,
    S S,
    z_t z_t,
    z_b z_b,
    rho_ref rho_ref,
    rho_0_pres rho_0_pres,
    G_e G_e,
    HII HII,
    HIO HIO,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS,
    dpa dpa,
    intz_dpa intz_dpa,
    intx_dpa intx_dpa,
    inty_dpa inty_dpa,
    bathyT bathyT,
    dz_neglect dz_neglect,
    useMassWghtInterp useMassWghtInterp
    );

subroutine, public int_spec_vol_dp_linear(
    T T,
    S S,
    p_t p_t,
    p_b p_b,
    alpha_ref alpha_ref,
    HI HI,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS,
    dza dza,
    intp_dza intp_dza,
    intx_dza intx_dza,
    inty_dza inty_dza,
    halo_size halo_size,
    bathyP bathyP,
    dP_neglect dP_neglect,
    useMassWghtInterp useMassWghtInterp
    );

} // namespace mom_eos_linear

Detailed Documentation

A simple linear equation of state for sea water with constant coefficients.

Global Functions

subroutine, public calculate_density_scalar_linear(
    T T,
    S S,
    pressure pressure,
    rho rho,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS,
    rho_ref rho_ref
    )

This subroutine computes the density of sea water with a trivial linear equation of state (in [kg m-3]) from salinity (sal [PSU]), potential temperature (T [degC]), and pressure [Pa].

Parameters:

t	Potential temperature relative to the surface [degC].
s	Salinity [PSU].
pressure	pressure [Pa].
rho	In situ density [kg m-3].
rho_t0_s0	The density at T=0, S=0 [kg m-3].
drho_dt	The derivatives of density with temperature [kg m-3 degC-1].
drho_ds	The derivatives of density with salinity in [kg m-3 ppt-1].
rho_ref	A reference density [kg m-3].

subroutine, public calculate_density_array_linear(
    T T,
    S S,
    pressure pressure,
    rho rho,
    start start,
    npts npts,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS,
    rho_ref rho_ref
    )

This subroutine computes the density of sea water with a trivial linear equation of state (in kg/m^3) from salinity (sal in psu), potential temperature (T [degC]), and pressure [Pa].

Parameters:

t	potential temperature relative to the surface [degC].
s	salinity [PSU].
pressure	pressure [Pa].
rho	in situ density [kg m-3].
start	the starting point in the arrays.
npts	the number of values to calculate.
rho_t0_s0	The density at T=0, S=0 [kg m-3].
drho_dt	The derivatives of density with temperature [kg m-3 degC-1].
drho_ds	The derivatives of density with salinity in [kg m-3 ppt-1].
rho_ref	A reference density [kg m-3].

subroutine, public calculate_density_derivs_scalar_linear(
    T T,
    S S,
    pressure pressure,
    drho_dT_out drho_dT_out,
    drho_dS_out drho_dS_out,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS
    )

This subroutine calculates the partial derivatives of density * with potential temperature and salinity for a single point.

Parameters:

t	Potential temperature relative to the surface [degC].
s	Salinity [PSU].
pressure	pressure [Pa].
drho_dt_out	The partial derivative of density with potential temperature [kg m-3 degC-1].
drho_ds_out	The partial derivative of density with salinity [kg m-3 ppt-1].
rho_t0_s0	The density at T=0, S=0 [kg m-3].
drho_dt	The derivatives of density with temperature [kg m-3 degC-1].
drho_ds	The derivatives of density with salinity [kg m-3 ppt-1].

subroutine, public calculate_specvol_derivs_linear(
    T T,
    S S,
    pressure pressure,
    dSV_dT dSV_dT,
    dSV_dS dSV_dS,
    start start,
    npts npts,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS
    )

Calculate the derivatives of specific volume with temperature and salinity.

Parameters:

t	Potential temperature relative to the surface [degC].
s	Salinity [PSU].
pressure	pressure [Pa].
dsv_ds	The partial derivative of specific volume with salinity [m3 kg-1 PSU-1].
dsv_dt	The partial derivative of specific volume with potential temperature [m3 kg-1 degC-1].
start	The starting point in the arrays.
npts	The number of values to calculate.
rho_t0_s0	The density at T=0, S=0 [kg m-3].
drho_dt	The derivative of density with temperature, [kg m-3 degC-1].
drho_ds	The derivative of density with salinity [kg m-3 ppt-1].

subroutine, public calculate_compress_linear(
    T T,
    S S,
    pressure pressure,
    rho rho,
    drho_dp drho_dp,
    start start,
    npts npts,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS
    )

This subroutine computes the in situ density of sea water (rho) and the compressibility (drho/dp == C_sound^-2) at the given salinity, potential temperature, and pressure.

Parameters:

t	Potential temperature relative to the surface [degC].
s	Salinity [PSU].
pressure	pressure [Pa].
rho	In situ density [kg m-3].
drho_dp	The partial derivative of density with pressure (also the inverse of the square of sound speed) [s2 m-2].
start	The starting point in the arrays.
npts	The number of values to calculate.
rho_t0_s0	The density at T=0, S=0 [kg m-3].
drho_dt	The derivative of density with temperature [kg m-3 degC-1].
drho_ds	The derivative of density with salinity [kg m-3 ppt-1].

subroutine, public int_density_dz_linear(
    T T,
    S S,
    z_t z_t,
    z_b z_b,
    rho_ref rho_ref,
    rho_0_pres rho_0_pres,
    G_e G_e,
    HII HII,
    HIO HIO,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS,
    dpa dpa,
    intz_dpa intz_dpa,
    intx_dpa intx_dpa,
    inty_dpa inty_dpa,
    bathyT bathyT,
    dz_neglect dz_neglect,
    useMassWghtInterp useMassWghtInterp
    )

This subroutine calculates analytical and nearly-analytical integrals of pressure anomalies across layers, which are required for calculating the finite-volume form pressure accelerations in a Boussinesq model.

Parameters:

hii	The horizontal index type for the input arrays.
hio	The horizontal index type for the output arrays.
t	Potential temperature relative to the surface
s	Salinity [PSU].
z_t	Height at the top of the layer in depth units [Z ~> m].
z_b	Height at the top of the layer [Z ~> m].
rho_ref	A mean density [kg m-3], that is subtracted out to reduce the magnitude of each of the integrals.
rho_0_pres	A density [kg m-3], that is used to calculate the pressure (as p~=-z*rho_0_pres*G_e) used in the equation of state. rho_0_pres is not used here.
g_e	The Earth’s gravitational acceleration [m2 Z-1 s-2 ~> m s-2].
rho_t0_s0	The density at T=0, S=0 [kg m-3].
drho_dt	The derivative of density with temperature, [kg m-3 degC-1].
drho_ds	The derivative of density with salinity, in [kg m-3 ppt-1].
dpa	The change in the pressure anomaly across the
intz_dpa	The integral through the thickness of the layer
intx_dpa	The integral in x of the difference between the
inty_dpa	The integral in y of the difference between the
bathyt	The depth of the bathymetry [Z ~> m].
dz_neglect	A miniscule thickness change [Z ~> m].
usemasswghtinterp	If true, uses mass weighting to interpolate T/S for top and bottom integrals.

subroutine, public int_spec_vol_dp_linear(
    T T,
    S S,
    p_t p_t,
    p_b p_b,
    alpha_ref alpha_ref,
    HI HI,
    Rho_T0_S0 Rho_T0_S0,
    dRho_dT dRho_dT,
    dRho_dS dRho_dS,
    dza dza,
    intp_dza intp_dza,
    intx_dza intx_dza,
    inty_dza inty_dza,
    halo_size halo_size,
    bathyP bathyP,
    dP_neglect dP_neglect,
    useMassWghtInterp useMassWghtInterp
    )

Calculates analytical and nearly-analytical integrals in pressure across layers of geopotential anomalies, which are required for calculating the finite-volume form pressure accelerations in a non-Boussinesq model. Specific volume is assumed to vary linearly between adjacent points.

Parameters:

hi	The ocean’s horizontal index type.
t	Potential temperature relative to the surface
s	Salinity [PSU].
p_t	Pressure at the top of the layer [Pa].
p_b	Pressure at the top of the layer [Pa].
alpha_ref	A mean specific volume that is subtracted out to reduce the magnitude of each of the integrals, m3 kg-1. The calculation is mathematically identical with different values of alpha_ref, but this reduces the effects of roundoff.
rho_t0_s0	The density at T=0, S=0 [kg m-3].
drho_dt	The derivative of density with temperature [kg m-3 degC-1].
drho_ds	The derivative of density with salinity, in [kg m-3 ppt-1].
dza	The change in the geopotential anomaly across
intp_dza	The integral in pressure through the layer of
intx_dza	The integral in x of the difference between the
inty_dza	The integral in y of the difference between the
halo_size	The width of halo points on which to calculate dza.
bathyp	The pressure at the bathymetry [Pa]
dp_neglect	A miniscule pressure change with the same units as p_t [Pa]
usemasswghtinterp	If true, uses mass weighting to interpolate T/S for top and bottom integrals.