compass.landice.tests.ismip7_calibration.quadratic.nonlocal_quadratic_melt

compass.landice.tests.ismip7_calibration.quadratic.nonlocal_quadratic_melt(gamma0, thermal_forcing, thermal_forcing_mean, constants=None, delta_t=0.0)[source]

Melt rate from the ISMIP6 non-local quadratic, in kg m-2 yr-1.

This is the parameterization MALI selects with config_basal_mass_bal_float = 'ismip6'. With a constant salinity it is algebraically identical to the Burgard semi-local form of protocol Eq. (2): only the decomposition of the constant differs, so every gamma0 has an exactly equivalent K. That is why the semi-local form is calibrated through this path rather than as a separate melt module.

Parameters:

  • gamma0 (float or xarray.DataArray) – The calibration parameter, in m yr-1

  • thermal_forcing (xarray.DataArray) – Local thermal forcing at the ice draft, in K

  • thermal_forcing_mean (xarray.DataArray) – Area-weighted mean thermal forcing over the basin each cell belongs to, in K

  • constants (Constants, optional) – The physical constants to use; defaults to MALI

  • delta_t (float or xarray.DataArray, optional) – Basin-wide thermal-forcing correction, K. Protocol Sect. 4.2.1 applies it wherever the thermal forcing appears, so it is added to both the local forcing and the basin mean.

Returns:

melt (xarray.DataArray) – Melt rate in kg m-2 yr-1, positive for melting