Changeset 3821 for trunk/LMDZ.COMMON/libf/evolution/layering_mod.F90

Timestamp:

Jul 1, 2025, 2:17:10 PM (38 hours ago)

Author:

jbclement

Message:

PEM:
Addition of the flag 'impose_dust_ratio' (default: .false.) to impose a dust-to-ice ratio instead of a dust tendency for the layering algorithm. The ratio value can be set in the "run_PEM.def" by 'dust_to_ice_ratio' (default: 0.01).
JBC

File:

• trunk/LMDZ.COMMON/libf/evolution/layering_mod.F90 (modified) (3 diffs)

trunk/LMDZ.COMMON/libf/evolution/layering_mod.F90

@@ -19 +19 @@
 
 ! Physical parameters
-real, parameter :: d_dust            = 1.e-3 ! Tendency of dust [kg.m-2.y-1]
-real, parameter :: dry_lag_porosity  = 0.4   ! Porosity of dust lag
-real, parameter :: wet_lag_porosity  = 0.1   ! Porosity of water ice lag
-real, parameter :: regolith_porosity = 0.4   ! Porosity of regolith
-real, parameter :: breccia_porosity  = 0.1   ! Porosity of breccia
-real, parameter :: co2ice_porosity   = 0.    ! Porosity of CO2 ice
-real, parameter :: h2oice_porosity   = 0.    ! Porosity of H2O ice
-real, parameter :: rho_dust          = 2500. ! Density of dust [kg.m-3]
-real, parameter :: rho_rock          = 3200. ! Density of rock [kg.m-3]
-real, parameter :: h_patchy_dust     = 5.e-4 ! Height under which a dust lag is considered patchy [m]
-real, parameter :: h_patchy_ice      = 5.e-4 ! Height under which a H2O ice lag is considered patchy [m]
+logical         :: impose_dust_ratio = .false. ! Impose dust-to-ice ratio instead of dust tendency (see 'dust2ice_ratio')
+real            :: dust2ice_ratio    = 0.01    ! Dust-to-ice ratio when ice condenses (1% by default)
+real            :: d_dust            = 1.e-3   ! Tendency of dust [kg.m-2.y-1]
+real, parameter :: dry_lag_porosity  = 0.4     ! Porosity of dust lag
+real, parameter :: wet_lag_porosity  = 0.1     ! Porosity of water ice lag
+real, parameter :: regolith_porosity = 0.4     ! Porosity of regolith
+real, parameter :: breccia_porosity  = 0.1     ! Porosity of breccia
+real, parameter :: co2ice_porosity   = 0.      ! Porosity of CO2 ice
+real, parameter :: h2oice_porosity   = 0.      ! Porosity of H2O ice
+real, parameter :: rho_dust          = 2500.   ! Density of dust [kg.m-3]
+real, parameter :: rho_rock          = 3200.   ! Density of rock [kg.m-3]
+real, parameter :: h_patchy_dust     = 5.e-4   ! Height under which a dust lag is considered patchy [m]
+real, parameter :: h_patchy_ice      = 5.e-4   ! Height under which a H2O ice lag is considered patchy [m]
 
 ! Parameters for CO2 flux correction (inspired by Levrard et al. 2007)
@@ -574 +576 @@
 ! Is the considered stratum a dust lag?
 if (.not. is_dust_lag(current)) return
-do while (is_dust_lag(current) .and. associated(current))
+do while (is_dust_lag(current))
     h_toplag = h_toplag + thickness(current)
-    current => current%down
+    if (associated(current%down)) then
+        current => current%down
+    else
+        exit
+    endif
 enddo
+
+if (.not. associated(current%down)) then ! Bottom of the layering -> no ice below
+    h_toplag = 0.
+    return
+endif
+
 ! Is the stratum below the dust lag made of ice?
-if (current%h_h2oice > 0. .and. current%h_h2oice > current%h_co2ice) then ! There is more H2O ice than CO2 ice
+if (current%h_h2oice > 0. .and. current%h_h2oice > current%h_co2ice) then ! Yes, there is more H2O ice than CO2 ice
     if (h_toplag < h_patchy_dust) then ! But the dust lag is too thin to considered ice as subsurface ice
         h_toplag = 0.
         h2o_ice = current%h_h2oice
     endif
-else if (current%h_co2ice > 0. .and. current%h_co2ice > current%h_h2oice) then ! There is more CO2 ice than H2O ice
+else if (current%h_co2ice > 0. .and. current%h_co2ice > current%h_h2oice) then ! No, there is more CO2 ice than H2O ice
     h_toplag = 0. ! Because it matters only for H2O ice
     if (h_toplag < h_patchy_ice) then ! But the dust lag is too thin to considered ice as subsurface ice
@@ -712 +724 @@
 dh_h2oice = d_h2oice/rho_h2oice
 ! To disable dust sedimenation when there is ice sublimation (because dust tendency is fixed)
-if (dh_co2ice > 0. .or. dh_h2oice > 0.) then
-    dh_dust = d_dust/rho_dust
+if (dh_co2ice >= 0. .and. dh_h2oice >= 0.) then
+    if (impose_dust_ratio) then
+        dh_dust = dust2ice_ratio*(dh_h2oice + dh_co2ice)
+    else 
+        dh_dust = d_dust/rho_dust
+    endif
 else
     dh_dust = 0.