Changeset 8125 for branches/2016/dev_r6859_LIM3_meltponds/NEMOGCM/NEMO/OPA_SRC/SBC/albedo.F90

Timestamp:

2017-06-02T08:53:53+02:00 (7 years ago)

Author:

vancop

Message:

Melt pond podifications

File:

• branches/2016/dev_r6859_LIM3_meltponds/NEMOGCM/NEMO/OPA_SRC/SBC/albedo.F90 (modified) (6 diffs)

branches/2016/dev_r6859_LIM3_meltponds/NEMOGCM/NEMO/OPA_SRC/SBC/albedo.F90

@@ -106 +106 @@
       REAL(wp), POINTER, DIMENSION(:,:,:) ::   zafrac_snw                ! relative snow fraction
       REAL(wp), POINTER, DIMENSION(:,:,:) ::   zafrac_ice                ! relative ice fraction
+      REAL(wp), POINTER, DIMENSION(:,:,:) ::   zafrac_pnd                ! relative ice fraction (effective)
       !!
       !!---------------------------------------------------------------------
@@ -117 +118 @@
       CALL wrk_alloc( jpi,jpj,ijpl, zalb, zalb_it )
       CALL wrk_alloc( jpi,jpj,ijpl, zalb_pnd, zalb_ice, zalb_snw )
-      CALL wrk_alloc( jpi,jpj,ijpl, zalb_pnd, zafrac_snw, zafrac_ice )
+      CALL wrk_alloc( jpi,jpj,ijpl, zalb_pnd, zafrac_snw, zafrac_ice, zafrac_pnd )
 
       IF( albd_init == 0 )   CALL albedo_init      ! initialization 
@@ -281 +282 @@
  
       ! MV: I propose this formulation that is more elegant, and more easy to expand towards
-      !     varying pond and snow fraction
- 
+      !     varying pond and snow fraction.
+      !     Formulation 1 has issues to handle ponds and snow together that
+      !     can't easily be fixed. This one handles it better, I believe.
+
           !-----------------------------------------
           ! Snow, bare ice and ponded ice fractions 
           !-----------------------------------------
           ! Specific fractions (zafrac) refer to relative area covered by snow within each ice category
- 
+
+          !--- Effective pond fraction (for now, we prevent melt ponds and snow at the same time)
+          zafrac_pnd = 0._wp
+          IF ( ld_pnd ) THEN  
+             WHERE( ph_snw == 0._wp ) ;  zafrac_pnd = pafrac_pnd ;  END WHERE  ! Snow fully "shades" melt ponds
+          ENDIF         
+
           !--- Specific snow fraction (for now, prescribed)
           WHERE     ( ph_snw > 0._wp     ) ;  zafrac_snw = 1.
@@ -294 +303 @@
  
           !--- Specific ice fraction 
-          zafrac_ice = 1. - zafrac_snw - pafrac_pnd
-!          WHERE     ( ph_ice > 1.0e-6_wp ) ;  zafrac_ice = 1. - zafrac_snw - pafrac_pnd
-!         ELSE WHERE                       ;  zafrac_ice = 0.
-!         ENDWHERE
+          zafrac_ice = 1. - zafrac_snw - zafrac_pnd
  
           !--------------------------------------------------
@@ -324 +330 @@
 
           ! Surface albedo is weighted mean of snow, ponds and bare ice contributions
-          pa_ice_os = zafrac_snw * zalb_snw  +  pafrac_pnd * zalb_pnd  +  zafrac_ice * zalb_ice
+          pa_ice_os = zafrac_snw * zalb_snw  +  zafrac_pnd * zalb_pnd  +  zafrac_ice * zalb_ice
           
           pa_ice_cs = pa_ice_os - ( - 0.1010 * pa_ice_os * pa_ice_os + 0.1933 * pa_ice_os - 0.0148 )
@@ -332 +338 @@
       CALL wrk_dealloc( jpi,jpj,ijpl, zalb, zalb_it )
       CALL wrk_dealloc( jpi,jpj,ijpl, zalb_pnd, zalb_ice, zalb_snw )
-      CALL wrk_dealloc( jpi,jpj,ijpl, zalb_pnd, zafrac_snw, zafrac_ice )
+      CALL wrk_dealloc( jpi,jpj,ijpl, zalb_pnd, zafrac_snw, zafrac_ice, zafrac_pnd )
       !
    END SUBROUTINE albedo_ice