From 14f42ab803344102f8b9def313f48b7c048c090a Mon Sep 17 00:00:00 2001
From: Tony Craig <apcraig@users.noreply.github.com>
Date: Tue, 25 Jan 2022 08:58:00 -0800
Subject: [PATCH] Add gbox12 and ice_data_type='smallblock' (#51)

* add gbox12 and ice_data_type='smallblock'

* update documentation

* update gbox12 default
---
 cicecore/cicedynB/general/ice_init.F90       | 16 +++++++++++++++-
 configuration/scripts/cice_decomp.csh        | 11 +++++++++++
 configuration/scripts/options/set_nml.gbox12 |  5 +++++
 doc/source/user_guide/ug_case_settings.rst   |  4 +++-
 4 files changed, 34 insertions(+), 2 deletions(-)
 create mode 100644 configuration/scripts/options/set_nml.gbox12

diff --git a/cicecore/cicedynB/general/ice_init.F90 b/cicecore/cicedynB/general/ice_init.F90
index 3292f6274..2c2327dd8 100644
--- a/cicecore/cicedynB/general/ice_init.F90
+++ b/cicecore/cicedynB/general/ice_init.F90
@@ -2687,7 +2687,7 @@ subroutine set_state_var (nx_block, ny_block, &
 
       if (trim(ice_ic) == 'default') then
 
-         if (trim(ice_data_type) == 'box2001') then
+         if (trim(ice_data_type) == 'box2001' .or. trim(ice_data_type) == 'smallblock') then
 
             hbar = c2  ! initial ice thickness
             do n = 1, ncat
@@ -2764,6 +2764,20 @@ subroutine set_state_var (nx_block, ny_block, &
                endif
             enddo
             enddo
+
+         else if (trim(ice_data_type) == 'smallblock') then
+            ! 2x2 ice in center of domain
+            icells = 0
+            do j = jlo, jhi
+            do i = ilo, ihi
+               if ((iglob(i) == nx_global/2 .or. iglob(i) == nx_global/2+1) .and. &
+                   (jglob(j) == ny_global/2 .or. jglob(j) == ny_global/2+1)) then
+                  icells = icells + 1
+                  indxi(icells) = i
+                  indxj(icells) = j
+               endif
+            enddo
+            enddo
             
          else ! default behavior
 
diff --git a/configuration/scripts/cice_decomp.csh b/configuration/scripts/cice_decomp.csh
index aa1bb9a54..0c6715f3b 100755
--- a/configuration/scripts/cice_decomp.csh
+++ b/configuration/scripts/cice_decomp.csh
@@ -66,6 +66,17 @@ else if (${grid} == 'gbox80') then
     set blckx = 8; set blcky = 8
   endif
 
+else if (${grid} == 'gbox12') then
+  set nxglob = 12
+  set nyglob = 12
+  if (${cicepes} <= 1) then
+    set blckx = 12; set blcky = 12
+  else if (${cicepes} <= 8) then
+    set blckx = 4; set blcky = 4
+  else
+    set blckx = 2; set blcky = 2
+  endif
+
 else if (${grid} == 'gx3') then
   set nxglob = 100
   set nyglob = 116
diff --git a/configuration/scripts/options/set_nml.gbox12 b/configuration/scripts/options/set_nml.gbox12
new file mode 100644
index 000000000..8063bee67
--- /dev/null
+++ b/configuration/scripts/options/set_nml.gbox12
@@ -0,0 +1,5 @@
+ice_ic = 'default'
+grid_type = 'rectangular'
+atm_data_type = 'box2001'
+ocn_data_type = 'calm'
+ice_data_type = 'box2001'
diff --git a/doc/source/user_guide/ug_case_settings.rst b/doc/source/user_guide/ug_case_settings.rst
index 8f763db2f..3f70ebb02 100644
--- a/doc/source/user_guide/ug_case_settings.rst
+++ b/doc/source/user_guide/ug_case_settings.rst
@@ -577,7 +577,9 @@ forcing_nml
    "``highfreq``", "logical", "high-frequency atmo coupling", "``.false.``"
    "``ice_data_type``", "``boxslotcyl``", "initialize ice concentration and velocity for :ref:`boxslotcyl` test (:cite:`Zalesak79`)", "``default``"
    "", "``box2001``", "initialize ice concentration for :ref:`box2001` test (:cite:`Hunke01`)", ""
-   "", "``default``", "no special initialization", ""
+   "", "``default``", "ice dependent on latitude and ocean temperature", ""
+   "", "``smallblock``", "uniform 2x2 block ice concentration and thickness in center of domain", ""
+   "", "``uniform``", "uniform ice concentration and thickness across domain", ""
    "``iceruf``", "real", "ice surface roughness at atmosphere interface", "0.0005"
    "``l_mpond_fresh``", "``.false.``", "release pond water immediately to ocean", "``.false.``"
    "", "``true``", "retain (topo) pond water until ponds drain", ""