Changeset 4071 for trunk/LMDZ.COMMON/libf/evolution/tendencies.F90

Timestamp:

Feb 16, 2026, 10:28:56 AM (12 days ago)

Author:

jbclement

Message:

PEM:

• Making the computation of ice tendencies more reliable by doing it after 'read_startpem' to know exactly where perennial ice is (no matter if there is a "startpem.nc" or not). Moreover, when there is no "startpem.nc", location of perennial ice depends now on 'watercaptag' and on huge amount of frost. This prevents negative ice tendency while there is no ice which can happen with weird PCM inputs (i.e. 'watercaptag' = F & 'watercap' /= 0 & no "stratpem.nc").
• Few small safeguards throughout the code.

JBC

File:

• trunk/LMDZ.COMMON/libf/evolution/tendencies.F90 (modified) (7 diffs)

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

@@ -18 +18 @@
 ! DEPENDENCIES
 ! ------------
-use numerics, only: dp, di, minieps, tol
+use numerics, only: dp, di, k4, minieps, tol
 
 ! DECLARATION
@@ -28 +28 @@
 
 !=======================================================================
-SUBROUTINE compute_tend(min_ice,d_ice)
-!-----------------------------------------------------------------------
-! NAME
-!     compute_tend
+SUBROUTINE compute_tendice(min_ice,is_perice,d_ice)
+!-----------------------------------------------------------------------
+! NAME
+!     compute_tendice
 !
 ! DESCRIPTION
@@ -51 +51 @@
 ! ARGUMENTS
 ! ---------
-real(dp), dimension(:,:,:), intent(in)  :: min_ice
-real(dp), dimension(:,:),   intent(out) :: d_ice
+real(dp),    dimension(:,:,:), intent(in)  :: min_ice
+logical(k4), dimension(:,:),   intent(in)  :: is_perice
+real(dp),    dimension(:,:),   intent(out) :: d_ice
 
 ! CODE
 ! ----
-! We compute the difference
-d_ice(:,:) = min_ice(:,:,2) - min_ice(:,:,1)
+! We compute the difference to get the tendency
+d_ice = min_ice(:,:,2) - min_ice(:,:,1)
 
 ! If the difference is too small, then there is no evolution
 where (abs(d_ice) < minieps) d_ice = 0._dp
 
-! If the minimum over the last year is 0, then we have no perennial ice
-where (abs(min_ice(:,:,2)) < minieps) d_ice = 0._dp
-
-END SUBROUTINE compute_tend
-!=======================================================================
-
-!=======================================================================
-SUBROUTINE evolve_tend_co2(d_co2ice_ini,co2ice,emissivity,q_co2_ts_ini,q_co2_ts,ps_PCM,ps_avg_glob_ini,ps_avg_global,d_co2ice)
-!-----------------------------------------------------------------------
-! NAME
-!     evolve_tend_co2
+! If the tendency is negative but there is no ice reservoir for the PEM
+where (abs(d_ice) < 0._dp .and. .not. is_perice) d_ice = 0._dp
+
+END SUBROUTINE compute_tendice
+!=======================================================================
+
+!=======================================================================
+SUBROUTINE evolve_tend_co2ice(d_co2ice_ini,co2ice,emissivity,q_co2_ts_ini,q_co2_ts,ps_PCM,ps_avg_glob_ini,ps_avg_global,d_co2ice)
+!-----------------------------------------------------------------------
+! NAME
+!     evolve_tend_co2ice
 !
 ! DESCRIPTION
@@ -135 +136 @@
 call print_msg('New CO2 ice tendencies [kg/m2/yr] (min|max): '//real2str( minval(d_co2ice))//' | '//real2str(maxval(d_co2ice)))
 
-END SUBROUTINE evolve_tend_co2
-!=======================================================================
-
-!=======================================================================
-SUBROUTINE evolve_tend_h2o(h2oice_depth_old,h2oice_depth_new,tsurf,tsoil_ts_old,tsoil_ts_new,d_h2oice)
-!-----------------------------------------------------------------------
-! NAME
-!     evolve_tend_h2o
+END SUBROUTINE evolve_tend_co2ice
+!=======================================================================
+
+!=======================================================================
+SUBROUTINE evolve_tend_h2oice(h2oice_depth_old,h2oice_depth_new,tsurf,tsoil_ts_old,tsoil_ts_new,d_h2oice)
+!-----------------------------------------------------------------------
+! NAME
+!     evolve_tend_h2oice
 !
 ! DESCRIPTION
@@ -158 +159 @@
 use soil_temp,      only: itp_tsoil
 use subsurface_ice, only: psv
+use display,        only: print_msg
 
 ! DECLARATION
@@ -181 +183 @@
 ! CODE
 ! ----
+call print_msg("> Updating the H2O sub-surface ice tendency due to lag layer")
+
 ! Higher resistance due to growing lag layer (higher depth)
 Rz_old = h2oice_depth_old*zcdv/coef_diff ! Old resistance from PCM
@@ -204 +208 @@
 d_h2oice = d_h2oice*R_dec*hum_dec
 
-END SUBROUTINE evolve_tend_h2o
+END SUBROUTINE evolve_tend_h2oice
 !=======================================================================