Regional BC blending and BCs into GSI (ufs-community#16)

* Add new code for boundary blending and for getting BCs into GSI updates.

driver/fvGFS/atmosphere.F90

@@ -509,7 +509,7 @@ subroutine atmosphere_init (Time_init, Time, Time_step, Grid_box, area)
 !  --- initiate the start for a restarted regional forecast
    if ( Atm(mytile)%gridstruct%regional .and. Atm(mytile)%flagstruct%warm_start ) then
 
-     call start_regional_restart(Atm(1),             &
+     call start_regional_restart(Atm(1), dt_atmos,   &
                                  isc, iec, jsc, jec, &
                                  isd, ied, jsd, jed )
    endif
@@ -1630,6 +1630,7 @@ subroutine atmosphere_state_update (Time, IPD_Data, IAU_Data, Atm_block, flip_vc
 
      call nullify_domain()
      call timing_on('FV_DIAG')
+
      call fv_diag(Atm(mytile:mytile), zvir, fv_time, Atm(mytile)%flagstruct%print_freq)
      first_diag = .false.
      call timing_off('FV_DIAG')

model/fv_arrays.F90

@@ -985,6 +985,7 @@ module fv_arrays_mod
                             !< The default value is 4 (recommended); fourth-order interpolation
                             !< is used unless c2l_ord = 2.
 
+   integer :: nrows_blend = 0   !< # of blending rows in the outer integration domain.
 
    real(kind=R_GRID) :: dx_const = 1000.   !< Specifies the (uniform) grid-cell-width in the x-direction
                                            !< on a doubly-periodic grid (grid_type = 4) in meters. 
@@ -1006,6 +1007,10 @@ module fv_arrays_mod
 
    integer :: bc_update_interval = 3   !< Default setting for interval (hours) between external regional BC data files.
 
+   logical :: regional_bcs_from_gsi = .false.   !< Default setting for using DA-updated BC files.
+
+   logical :: write_restart_with_bcs = .false.   !< Default setting for writing restart files with boundary rows.
+
    !>Convenience pointers
    integer, pointer :: grid_number
 

model/fv_control.F90

@@ -331,6 +331,9 @@ module fv_control_mod
   logical, pointer :: nested, twowaynest
   logical, pointer :: regional
   integer, pointer :: bc_update_interval 
+  integer, pointer :: nrows_blend
+  logical, pointer :: regional_bcs_from_gsi
+  logical, pointer :: write_restart_with_bcs
   integer, pointer :: parent_tile, refinement, nestbctype, nestupdate, nsponge, ioffset, joffset
   real, pointer :: s_weight, update_blend
 
@@ -670,7 +673,8 @@ subroutine run_setup(Atm, dt_atmos, grids_on_this_pe, p_split)
                          nested, twowaynest, parent_grid_num, parent_tile, nudge_qv, &
                          refinement, nestbctype, nestupdate, nsponge, s_weight, &
                          ioffset, joffset, check_negative, nudge_ic, halo_update_type, gfs_phil, agrid_vel_rst,     &
-                         do_uni_zfull, adj_mass_vmr, fac_n_spl, fhouri, regional, bc_update_interval
+                         do_uni_zfull, adj_mass_vmr, fac_n_spl, fhouri, regional, bc_update_interval,  &
+                         regional_bcs_from_gsi, write_restart_with_bcs, nrows_blend
 
    namelist /test_case_nml/test_case, bubble_do, alpha, nsolitons, soliton_Umax, soliton_size
 #ifdef MULTI_GASES
@@ -892,6 +896,12 @@ subroutine run_setup(Atm, dt_atmos, grids_on_this_pe, p_split)
          Atm(n)%neststruct%refinement             = -1
       end if
 
+      if (Atm(n)%flagstruct%regional) then
+         if ( consv_te > 0.) then
+            call mpp_error(FATAL, 'The global energy fixer cannot be used on a regional grid. consv_te must be set to 0.')
+         end if
+      end if
+
       if (Atm(n)%neststruct%nested) then
          if (Atm(n)%flagstruct%grid_type >= 4 .and. Atm(n)%parent_grid%flagstruct%grid_type >= 4) then
             Atm(n)%flagstruct%dx_const = Atm(n)%parent_grid%flagstruct%dx_const / real(Atm(n)%neststruct%refinement)
@@ -1233,6 +1243,9 @@ subroutine setup_pointers(Atm)
      target_lon                    => Atm%flagstruct%target_lon
      regional                      => Atm%flagstruct%regional
      bc_update_interval            => Atm%flagstruct%bc_update_interval 
+     nrows_blend                   => Atm%flagstruct%nrows_blend
+     regional_bcs_from_gsi         => Atm%flagstruct%regional_bcs_from_gsi
+     write_restart_with_bcs        => Atm%flagstruct%write_restart_with_bcs
      reset_eta                     => Atm%flagstruct%reset_eta
      p_fac                         => Atm%flagstruct%p_fac
      a_imp                         => Atm%flagstruct%a_imp