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Add basal melt draft dependence subroutine
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Shivaprakash Muruganandham committed Feb 6, 2024
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111 changes: 111 additions & 0 deletions components/mpas-albany-landice/src/mode_forward/mpas_li_iceshelf_melt.F
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Expand Up @@ -582,6 +582,117 @@ end subroutine li_basal_melt_floating_ice
!***********************************************************************
!|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
!
! ! routine basal_melt_draft_dependence
!
!> \brief Calculate ice shelf melt rate from depth param.
!> \author Shivaprakash Muruganandham
!> \date February 2024
!> \details
!> Melt rate parameterization from:
!> Seroussi, H., Y. Nakayama, E. Larour, D. Menemenlis, M. Morlighem, E. Rignot, and A. Khazendar (2017),
!> Continued retreat of Thwaites Glacier, West Antarctica, controlled by bed topography and ocean circulation,
!> Geophys. Res. Lett., 1-9, doi:10.1002/2017GL072910.
!> for Thwaites Glacier.
!> Specifically, this is similar to the linear fit of melt with shelf draft from the Supplemental Information, Figure S1.
!> The linear relation is modified by a:
!> * depth above which there is no melt (Antarctic Surface Water saturation)
!> * a maximum melt rate (Circumpolar Deep Water saturation)
!> * a depth below which melt stops increasing (minimum sill height)
!-----------------------------------------------------------------------
subroutine basal_melt_draft_dependence(floatingBasalMassBal, daysSinceStart, lowerSurface, cellMask, &
config_sea_level, config_ice_density, nCellsSolve, err)
!-----------------------------------------------------------------
! input variables
!-----------------------------------------------------------------
!real(kind=RKIND), pointer, intent(in) :: daysSinceStart
!real (kind=RKIND), dimension(:), pointer, intent(in) :: lowerSurface !< lower surface elevation (m)
!integer, dimension(:), pointer, intent(in) :: &
! cellMask !< bit mask describing whether ice is floating, dynamically active, etc.
!real(kind=RKIND), pointer, intent(in) :: &
! config_sea_level !< sea level (m) relative to z = 0
!real (kind=RKIND), pointer, intent(in) :: config_ice_density !< ice density
!integer, pointer :: &
! nCellsSolve !< number of locally owned cells
!-----------------------------------------------------------------
! input/output variables
!-----------------------------------------------------------------
!-----------------------------------------------------------------
! output variables
!-----------------------------------------------------------------
!real (kind=RKIND), dimension(:), pointer, intent(out) :: &
! floatingBasalMassBal !< basal mass balance for floating ice
!integer, intent(out) :: err !< Output: error flag
!-----------------------------------------------------------------
! local variables
!-----------------------------------------------------------------
!real (kind=RKIND) :: slopeSer ! slope of relation between depth and melt rate
!real (kind=RKIND) :: interceptSer ! depth at which melting goes to 0
!real (kind=RKIND) :: maxMeltSer ! maximum allowable melt rate
!real (kind=RKIND) :: sillDepth ! depth below which melt rate no longer increases
!real (kind=RKIND), pointer :: config_basal_mass_bal_seroussi_amplitude
!real (kind=RKIND), pointer :: config_basal_mass_bal_seroussi_period
!real (kind=RKIND), pointer :: config_basal_mass_bal_seroussi_phase
!real(kind=RKIND) :: hCavity ! depth of ice cavity beneath floating ice (m)
!real(kind=RKIND) :: zDraft ! draft of floating ice (m below sea level)
!integer :: iCell
!err = 0
!call mpas_pool_get_config(liConfigs, 'config_basal_mass_bal_seroussi_amplitude', &
! config_basal_mass_bal_seroussi_amplitude) ! meters
!call mpas_pool_get_config(liConfigs, 'config_basal_mass_bal_seroussi_period', &
! config_basal_mass_bal_seroussi_period) ! years
!call mpas_pool_get_config(liConfigs, 'config_basal_mass_bal_seroussi_phase', &
! config_basal_mass_bal_seroussi_phase) ! cycles
!slopeSer = 0.088_RKIND ! slope of relation between depth and melt rate (melt (m/yr) per depth (m))
!interceptSer = -100.0_RKIND ! depth (m) at which melting goes to 0 (negative meaning below sea level)
!maxMeltSer = 50.0_RKIND ! maximum allowable melt rate (m/yr) (positive meaning melting)
!sillDepth = -650.0_RKIND ! depth below which melt stops increasing (m) (negative meaning below sea level)
!if (config_basal_mass_bal_seroussi_period <= 0.0_RKIND) then
! call mpas_log_write("Value for config_basal_mass_bal_seroussi_period has to be a positive real value.", MPAS_LOG_ERR)
! err = ior(err, 1)
!endif
! Modify intercept height for variability parameters
!interceptSer = interceptSer + config_basal_mass_bal_seroussi_amplitude * &
! sin( (2.0_RKIND * pii / config_basal_mass_bal_seroussi_period) * (daysSinceStart/365.0_RKIND) &
! + 2.0_RKIND * pii * config_basal_mass_bal_seroussi_phase)
! Initialize before computing
!floatingBasalMassBal(:) = 0.0_RKIND
!do iCell = 1, nCellsSolve
! Shut off melt at an arbitrary shallow depth to discourage ice from disappearing.
!if ( (li_mask_is_floating_ice(cellMask(iCell))) .and. (lowerSurface(iCell) < -10.0_RKIND) ) then
! ice is present and floating
!zDraft = lowerSurface(iCell) - config_sea_level
! Coefficients for m/yr melt rate (in units of Seroussi figure but without negative meaning melting)
!floatingBasalMassBal(iCell) = max(-1.0_RKIND * maxMeltSer, min(0.0_RKIND, slopeSer * &
! (max(zDraft, sillDepth) - interceptSer)))
!endif ! ice is present
!enddo ! iCell
! change units from m/yr to kg/m2/s
!floatingBasalMassBal(:) = floatingBasalMassBal(:) * config_ice_density / scyr
end subroutine basal_melt_draft_dependence
!-----------------------------------------------------------------------
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!
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