Add ability to read increment files on native cubed sphere grid (#837)

* Add namelist parameter, ncrement_file_on_native_grid

atmos_model.F90

@@ -407,7 +407,7 @@ subroutine update_atmos_radiation_physics (Atmos)
         if (mpp_pe() == mpp_root_pe()) print *,'PHYSICS STEP2   ', GFS_control%kdt, GFS_control%fhour
         call fv3atm_checksum(GFS_control, GFS_Statein, GFS_Stateout, GFS_Grid, GFS_Tbd, GFS_Cldprop, GFS_Sfcprop, GFS_Radtend, GFS_Coupling, Atm_block)
       endif
-      call getiauforcing(GFS_control,IAU_data)
+      call getiauforcing(GFS_control,IAU_data,Atm(mygrid))
       if (mpp_pe() == mpp_root_pe() .and. debug) write(6,*) "end of radiation and physics step"
 
 !--- execute the atmospheric timestep finalize step
@@ -725,7 +725,7 @@ subroutine atmos_model_init (Atmos, Time_init, Time, Time_step)
    Atm(mygrid)%flagstruct%do_skeb = GFS_control%do_skeb
 
 !  initialize the IAU module
-   call iau_initialize (GFS_control,IAU_data,Init_parm)
+   call iau_initialize (GFS_control,IAU_data,Init_parm,Atm(mygrid))
 
    Init_parm%blksz           => null()
    Init_parm%ak              => null()

ccpp/data/GFS_typedefs.F90

@@ -1606,6 +1606,9 @@ module GFS_typedefs
     real(kind=kind_phys), pointer :: si(:)  !< vertical sigma coordinate for model initialization
     real(kind=kind_phys)          :: sec    !< seconds since model initialization
 
+!--- Increment grid    
+    logical              :: increment_file_on_native_grid ! increment on native grid else Gaussian grid
+
 !--- IAU
     integer              :: iau_offset
     real(kind=kind_phys) :: iau_delthrs     ! iau time interval (to scale increments) in hours
@@ -3889,6 +3892,9 @@ subroutine control_initialize (Model, nlunit, fn_nml, me, master, &
     logical              :: ca_entr        = .false.
     logical              :: ca_trigger     = .false.
 
+!--- Increment grid
+    logical               :: increment_file_on_native_grid = .false. ! increment on native grid else Gaussian grid
+
 !--- IAU options
     real(kind=kind_phys)  :: iau_delthrs      = 0           !< iau time interval (to scale increments)
     character(len=240)    :: iau_inc_files(7) = ''          !< list of increment files
@@ -4110,6 +4116,8 @@ subroutine control_initialize (Model, nlunit, fn_nml, me, master, &
                                nseed,  nseed_g,  nthresh, do_ca, ca_advect,                 &
                                ca_sgs, ca_global,iseed_ca,ca_smooth,                        &
                                nspinup,ca_amplitude,nsmooth,ca_closure,ca_entr,ca_trigger,  &
+                          !--- Increment grid
+                               increment_file_on_native_grid,                               &
                           !--- IAU
                                iau_delthrs,iaufhrs,iau_inc_files,iau_filter_increments,     &
                                iau_drymassfixer,                                            &