compass.landice.tests.ismip7_calibration.quadratic.local_quadratic_melt

compass.landice.tests.ismip7_calibration.quadratic.local_quadratic_melt(k, thermal_forcing, salinity, slope, thermal_forcing_avg=None, constants=None, delta_t=0.0)[source]

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

Parameters:

  • k (float or xarray.DataArray) – The calibration parameter K.

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

  • salinity (xarray.DataArray) – Practical salinity at the ice draft.

  • slope (float or xarray.DataArray) – Ice-draft slope angle in radians (positive). A scalar gives the “constant Antarctic-mean slope” variant; a field gives the slope-dependent one.

  • delta_t (float or xarray.DataArray, optional) – Basin-wide thermal-forcing correction, K. Protocol §4.2.1 applies it wherever the thermal forcing appears, so it is added to both the local forcing and the averaged one. Defaults to zero, which is what the calibration uses; production runs are expected to use non-zero values.

  • thermal_forcing_avg (xarray.DataArray, optional) – Thermal forcing to use in the |TF| factor. Defaults to thermal_forcing, giving the local form; pass a shelf- or basin-average for the semi-local form of protocol Eq. (2).

Returns:

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

Notes

Melt is exactly linear in k, which is what allows the calibration to use one model run per ocean state rather than one per (state, parameter) pair; see the linearity of melt in the parameter.