PISM, A Parallel Ice Sheet Model  stable v2.1-1-g6902d5502 committed by Ed Bueler on 2023-12-20 08:38:27 -0800

◆ subshelf_salinity_melt()

void pism::ocean::GivenTH::subshelf_salinity_melt ( const Constants c,
double  sea_water_salinity,
double  sea_water_potential_temperature,
double  thickness,
double *  shelf_base_salinity 
)
private

Compute basal salinity in the basal melt case.

We use the parameterization of the temperature gradient from [Hellmeretal1998], equation 13:

\[ T_{\text{grad}} = -\Delta T\, \frac{\frac{\partial h}{\partial t}}{\kappa}, \]

where \( \Delta T \) is the difference between the ice temperature at the top of the ice column and its bottom: \( \Delta T = T^S - T^B. \) With this parameterization, we have

\[ Q_T^I = \rho_I\, c_{pI}\, {\frac{\partial h}{\partial t}}\, (T^S - T^B). \]

Then the coefficients of the quadratic equation for basal salinity (see pointwise_update()) are

\begin{align*} A &= a_{0}\,\gamma_S\,c_{pI}-b_{0}\,\gamma_T\,c_{pW}\\ B &= \gamma_S\,\left(L-c_{pI}\,\left(T^S+a_{0}\,S^W-a_{2}\,h-a_{1}\right)\right)+ \gamma_T\,c_{pW}\,\left(\Theta^W-b_{2}\,h-b_{1}\right)\\ C &= -\gamma_S\,S^W\,\left(L-c_{pI}\,\left(T^S-a_{2}\,h-a_{1}\right)\right) \end{align*}

Parameters
[in]cphysical constants, stored here to avoid looking them up in a double for loop
[in]sea_water_salinitysalinity of the ocean immediately adjacent to the shelf, [g/kg]
[in]sea_water_potential_temperaturepotential temperature of the sea water, [degrees Celsius]
[in]thicknessthickness of the ice shelf, [meters]
[out]shelf_base_salinityresulting shelf base salinity
Returns
0 on success

Definition at line 370 of file GivenTH.cc.

References pism::ocean::GivenTH::Constants::a, pism::ocean::GivenTH::Constants::b, C, pism::ocean::GivenTH::Constants::gamma_S, pism::ocean::GivenTH::Constants::gamma_T, pism::ocean::GivenTH::Constants::ice_specific_heat_capacity, L, pism::ocean::GivenTH::Constants::sea_water_specific_heat_capacity, pism::ocean::GivenTH::Constants::shelf_top_surface_temperature, and pism::ocean::GivenTH::Constants::water_latent_heat_fusion.

Referenced by subshelf_salinity().