set aream for rof when it is not computed by us

it should be better to compute ourselves, if we have the
mesh information
this could be a performance sink

driver-moab/main/component_mod.F90

@@ -471,6 +471,8 @@ subroutine component_init_aream(infodata, rof_c2_ocn, samegrid_ao, samegrid_al,
     !   character(1024)         :: domain_file        ! file containing domain info (set my input)
     use seq_comm_mct,     only: mboxid ! iMOAB id for MPAS ocean migrated mesh to coupler pes
     use seq_comm_mct,     only: mbaxid ! iMOAB id for atm migrated mesh to coupler pes
+    use seq_comm_mct,     only: mbrxid ! iMOAB id for rof migrated mesh to coupler pes
+    use seq_comm_mct,     only: mb_rof_aream_computed
 #endif
     !
     ! Arguments
@@ -527,6 +529,9 @@ subroutine component_init_aream(infodata, rof_c2_ocn, samegrid_ao, samegrid_al,
           dom_s%data%rAttr(km,:) = dom_s%data%rAttr(ka,:)
 
 #ifdef HAVE_MOAB
+        ! TODO should actually compute aream from mesh model
+        ! we do a lot of unnecessary gymnastics, and very inefficient, because we have a 
+        ! different distribution compared to mct source grid atm
          tagtype = 1 ! dense, double
          tagname='aream'//C_NULL_CHAR
          nloc = mct_avect_lsize(dom_s%data)
@@ -542,6 +547,8 @@ subroutine component_init_aream(infodata, rof_c2_ocn, samegrid_ao, samegrid_al,
             write(logunit,*) subname,' error in setting the aream tag on atm '
             call shr_sys_abort(subname//' ERROR in setting aream tag on atm ')
          endif
+         deallocate(gids)
+         deallocate(data1)
          ! project now aream on ocean (from atm)
 #endif
          call seq_map_map(mapper_Fa2o, av_s=dom_s%data, av_d=dom_d%data, fldlist='aream')
@@ -597,7 +604,31 @@ subroutine component_init_aream(infodata, rof_c2_ocn, samegrid_ao, samegrid_al,
                gsmap_s=gsmap_s, av_s=dom_s%data, avfld_s='aream', filefld_s='area_a', &
                string='rof2ocn ice aream initialization')
           call t_stopf('CPL:seq_map_readdata-rof2ocn_ice')
-
+          ! this should be more efficient if we just compute aream on coupler side, from actual mesh that we have
+          ! we need to expose that method in iMOAB, which is local
+          ! what we do here, we get aream from the domain dom_rx, we just filled it above, with readdata 
+          if(.not. mb_rof_aream_computed) then
+
+            ! we do a lot of unnecessary gymnastics, and very inefficient, because we have a 
+            ! different distribution compared to mct source grid atm
+            tagtype = 1 ! dense, double
+            tagname='aream'//C_NULL_CHAR
+            nloc = mct_avect_lsize(dom_s%data)
+            allocate(data1(nloc))
+            data1 = dom_s%data%rAttr(ka,:)
+            ent_type = 1  ! element dense double tags
+            allocate(gids(nloc))
+            gids = dom_s%data%iAttr(mct_aVect_indexIA(dom_s%data,"GlobGridNum"),:)
+            ! ! now set data on the coupler side too
+            ierr = iMOAB_SetDoubleTagStorageWithGid ( mbrxid, tagname, nloc, ent_type, &
+                                                      data1, gids)
+            if (ierr .ne. 0) then
+               write(logunit,*) subname,' error in setting the aream tag on rof '
+               call shr_sys_abort(subname//' ERROR in setting aream tag on rof ')
+            endif
+            deallocate(gids)
+            deallocate(data1)
+          endif
        endif
     end if
 

driver-moab/main/prep_lnd_mod.F90

@@ -18,6 +18,7 @@ module prep_lnd_mod
   use seq_comm_mct,     only: mbrxid   !          iMOAB id of moab rof on coupler pes (FV now)
   use seq_comm_mct,     only: mbintxal ! iMOAB id for intx mesh between atm and lnd
   use seq_comm_mct,     only: mbintxrl ! iMOAB id for intx mesh between river and land
+  use seq_comm_mct,     only: mb_rof_aream_computed  ! signal
 
   use seq_comm_mct,     only: mbaxid   ! iMOAB id for atm migrated mesh to coupler pes
   use seq_comm_mct,     only: atm_pg_active  ! whether the atm uses FV mesh or not ; made true if fv_nphys > 0
@@ -327,6 +328,9 @@ subroutine prep_lnd_init(infodata, atm_c2_lnd, rof_c2_lnd, glc_c2_lnd, iac_c2_ln
                                                 fNoBubble, monotonicity, volumetric, fInverseDistanceMap, &
                                                 noConserve, validate, &
                                                 trim(dofnameS), trim(dofnameT) )
+
+              ! signal that the aream for rof has been computed
+              mb_rof_aream_computed = .true.
               if (ierr .ne. 0) then
                 write(logunit,*) subname,' error in computing rl weights '
                 call shr_sys_abort(subname//' ERROR in computing rl weights ')

driver-moab/main/prep_rof_mod.F90

@@ -30,6 +30,7 @@ module prep_rof_mod
   use component_type_mod, only: ocn ! used for context for projection towards ocean from rof !
   use prep_lnd_mod, only: prep_lnd_get_mapper_Fr2l
   use map_lnd2rof_irrig_mod, only: map_lnd2rof_irrig
+  use seq_comm_mct,     only: mb_rof_aream_computed  ! signal
 
   use iso_c_binding
 #ifdef MOABCOMP
@@ -417,6 +418,7 @@ subroutine prep_rof_init(infodata, lnd_c2_rof, atm_c2_rof, ocn_c2_rof)
                                                 fNoBubble, monotonicity, volumetric, fInverseDistanceMap, &
                                                 noConserve, validate, &
                                                 trim(dofnameS), trim(dofnameT) )
+               mb_rof_aream_computed = .true. ! signal
                if (ierr .ne. 0) then
                   write(logunit,*) subname,' error in computing lr weights '
                   call shr_sys_abort(subname//' ERROR in computing lr weights ')

driver-moab/shr/seq_comm_mct.F90

@@ -247,6 +247,7 @@ module seq_comm_mct
   integer, public :: mbintxrl ! iMOAB id for intx mesh between river and land
 
   integer, public :: num_moab_exports   ! iMOAB id for atm phys grid, on atm pes
+  logical, public :: mb_rof_aream_computed = .false.  ! whether the aream for rof has been set or not 
 
   !=======================================================================
 contains