diff --git a/.zenodo.json b/.zenodo.json
index d96cfb9bb..fa46def55 100644
--- a/.zenodo.json
+++ b/.zenodo.json
@@ -1,22 +1,22 @@
 {
     "license": "BSD-3-Clause",
-    "copyright": "Copyright 1998-2025 Triad National Security, LLC",
+    "copyright": "Copyright 1998-2026 Triad National Security, LLC",
     "description": "View detailed release notes at https://github.com/CICE-Consortium/CICE/releases", 
     "language": "eng", 
-    "title": "CICE-Consortium/CICE: CICE Version 6.6.2", 
+    "title": "CICE-Consortium/CICE: CICE Version 6.6.3", 
     "keywords": [
         "sea ice model",
         "CICE",
         "Icepack"
     ], 
-    "version": "6.6.2", 
+    "version": "6.6.3", 
     "upload_type": "software", 
     "communities": [
         {
             "identifier": "cice-consortium"
         }
     ], 
-    "publication_date": "2025-08-15", 
+    "publication_date": "2026-01-22", 
     "creators": [
         {
             "affiliation": "Los Alamos National Laboratory", 
diff --git a/COPYRIGHT.pdf b/COPYRIGHT.pdf
index 2f37e495f..6a8923c95 100644
Binary files a/COPYRIGHT.pdf and b/COPYRIGHT.pdf differ
diff --git a/cicecore/cicedyn/analysis/ice_history.F90 b/cicecore/cicedyn/analysis/ice_history.F90
index 3d5f47312..83ecd6563 100644
--- a/cicecore/cicedyn/analysis/ice_history.F90
+++ b/cicecore/cicedyn/analysis/ice_history.F90
@@ -1455,10 +1455,10 @@ subroutine init_hist (dt)
              "weighted by ice area", c1, c0,                     &
               ns1, f_FY)
 
-      ! CMIP 2D variables (for "intensive" variables per Notz et al 2016 definition, 
+      ! CMIP 2D variables (for "intensive" variables per Notz et al 2016 definition,
       ! that is a weighted time average when ice is present)
-      ! Use avg_ice_present = 'init', 'final', 'pond', or 'ridge' to divide by 
-      ! sum(aice), sum(apond), or sum(ardg) over time 
+      ! Use avg_ice_present = 'init', 'final', 'pond', or 'ridge' to divide by
+      ! sum(aice), sum(apond), or sum(ardg) over time
       ! aice is at the start of the timestep ('init') or the end of the timestep ('final')
       ! avg_ice_present = 'none' produces a time average including zeroes when ice is not present
 
@@ -1694,7 +1694,7 @@ subroutine init_hist (dt)
              ns1, f_sidconcdyn, avg_ice_present='none', mask_ice_free_points=.false.)
 
          call define_hist_field(n_sidconcth,"sidconcth","1/s",tstr2D, tcstr,                  &
-             "sea-ice area fraction tendency due to thermodynamics",                          & 
+             "sea-ice area fraction tendency due to thermodynamics",                          &
              "total rate of change in sea-ice area fraction through thermodynamic processes", &
              c1, c0,                                                                          &
              ns1, f_sidconcth, avg_ice_present='none', mask_ice_free_points=.false.)
diff --git a/cicecore/cicedyn/analysis/ice_history_mechred.F90 b/cicecore/cicedyn/analysis/ice_history_mechred.F90
index f3707f6f6..318132a92 100644
--- a/cicecore/cicedyn/analysis/ice_history_mechred.F90
+++ b/cicecore/cicedyn/analysis/ice_history_mechred.F90
@@ -412,9 +412,9 @@ subroutine accum_hist_mechred (iblk)
              call accum_hist_field(n_sirdgconc,   iblk, &
                              aice(:,:,iblk) * (c1 - trcr(:,:,nt_alvl,iblk)), a2D)
 
-         if (f_sirdgthick(1:1)/= 'x') then 
+         if (f_sirdgthick(1:1)/= 'x') then
              call accum_hist_field(n_sirdgthick,  iblk, &
-                             vice(:,:,iblk) * (c1 - trcr(:,:,nt_vlvl,iblk)), a2D) 
+                             vice(:,:,iblk) * (c1 - trcr(:,:,nt_vlvl,iblk)), a2D)
          endif
 
          endif ! allocated(a2D)
diff --git a/cicecore/drivers/direct/hadgem3/CICE.F90 b/cicecore/drivers/direct/hadgem3/CICE.F90
index ad02ca51b..cacf96c46 100644
--- a/cicecore/drivers/direct/hadgem3/CICE.F90
+++ b/cicecore/drivers/direct/hadgem3/CICE.F90
@@ -1,5 +1,5 @@
 !=======================================================================
-! Copyright 1998-2025, Triad National Security, LLC
+! Copyright 1998-2026, Triad National Security, LLC
 ! All rights reserved.
 !
 ! This program was produced under U.S. Government contract 89233218CNA000001
diff --git a/cicecore/drivers/mapl/geos/CICE_copyright.txt b/cicecore/drivers/mapl/geos/CICE_copyright.txt
index ab684c63e..bc8975d79 100644
--- a/cicecore/drivers/mapl/geos/CICE_copyright.txt
+++ b/cicecore/drivers/mapl/geos/CICE_copyright.txt
@@ -1,4 +1,4 @@
-! Copyright 1998-2025, Triad National Security, LLC
+! Copyright 1998-2026, Triad National Security, LLC
 ! All rights reserved.
 !
 ! This program was produced under U.S. Government contract 89233218CNA000001
diff --git a/cicecore/drivers/mct/cesm1/CICE_copyright.txt b/cicecore/drivers/mct/cesm1/CICE_copyright.txt
index ab684c63e..bc8975d79 100644
--- a/cicecore/drivers/mct/cesm1/CICE_copyright.txt
+++ b/cicecore/drivers/mct/cesm1/CICE_copyright.txt
@@ -1,4 +1,4 @@
-! Copyright 1998-2025, Triad National Security, LLC
+! Copyright 1998-2026, Triad National Security, LLC
 ! All rights reserved.
 !
 ! This program was produced under U.S. Government contract 89233218CNA000001
diff --git a/cicecore/drivers/nuopc/cmeps/CICE_copyright.txt b/cicecore/drivers/nuopc/cmeps/CICE_copyright.txt
index ab684c63e..bc8975d79 100644
--- a/cicecore/drivers/nuopc/cmeps/CICE_copyright.txt
+++ b/cicecore/drivers/nuopc/cmeps/CICE_copyright.txt
@@ -1,4 +1,4 @@
-! Copyright 1998-2025, Triad National Security, LLC
+! Copyright 1998-2026, Triad National Security, LLC
 ! All rights reserved.
 !
 ! This program was produced under U.S. Government contract 89233218CNA000001
diff --git a/cicecore/drivers/nuopc/dmi/CICE.F90 b/cicecore/drivers/nuopc/dmi/CICE.F90
index 14c7af346..a96ca4ce7 100644
--- a/cicecore/drivers/nuopc/dmi/CICE.F90
+++ b/cicecore/drivers/nuopc/dmi/CICE.F90
@@ -1,5 +1,5 @@
 !=======================================================================
-! Copyright 1998-2025, Triad National Security, LLC
+! Copyright 1998-2026, Triad National Security, LLC
 ! All rights reserved.
 !
 ! This program was produced under U.S. Government contract 89233218CNA000001
diff --git a/cicecore/drivers/standalone/cice/CICE.F90 b/cicecore/drivers/standalone/cice/CICE.F90
index 14c7af346..a96ca4ce7 100644
--- a/cicecore/drivers/standalone/cice/CICE.F90
+++ b/cicecore/drivers/standalone/cice/CICE.F90
@@ -1,5 +1,5 @@
 !=======================================================================
-! Copyright 1998-2025, Triad National Security, LLC
+! Copyright 1998-2026, Triad National Security, LLC
 ! All rights reserved.
 !
 ! This program was produced under U.S. Government contract 89233218CNA000001
diff --git a/cicecore/drivers/unittest/opticep/CICE.F90 b/cicecore/drivers/unittest/opticep/CICE.F90
index 14c7af346..a96ca4ce7 100644
--- a/cicecore/drivers/unittest/opticep/CICE.F90
+++ b/cicecore/drivers/unittest/opticep/CICE.F90
@@ -1,5 +1,5 @@
 !=======================================================================
-! Copyright 1998-2025, Triad National Security, LLC
+! Copyright 1998-2026, Triad National Security, LLC
 ! All rights reserved.
 !
 ! This program was produced under U.S. Government contract 89233218CNA000001
diff --git a/cicecore/drivers/unittest/opticep/README b/cicecore/drivers/unittest/opticep/README
index b5f1bdf9c..958e592da 100644
--- a/cicecore/drivers/unittest/opticep/README
+++ b/cicecore/drivers/unittest/opticep/README
@@ -1,7 +1,7 @@
 
 This unittest tests Icepack optional arguments.  The idea is to have source code that is
 identical to the standard CICE source code except the significant optional arguments passed
-into Icepack are removed from the CICE calls.  Then to run a standard CICE case with optional 
+into Icepack are removed from the CICE calls.  Then to run a standard CICE case with optional
 features (fsd, bgc, isotopes, etc) off in namelist.  That results should be bit-for-bit identical
 with an equivalent run from the standard source code.
 
@@ -18,7 +18,7 @@ today, that includes
   CICE_InitMod.F90
   CICE_RunMod.F90
 
-Add 
+Add
   write(nu_diag, *) "OPTICEP TEST COMPLETED SUCCESSFULLY "
 to CICE_FinalMod.F90
 
@@ -26,5 +26,5 @@ Do not worry about the parameter/tracer query/init/write methods
 
 Interfaces to modify include
   ice_init_column.F90  (icepack_step_radiation, icepack_init_zbgc)
-  ice_step_mod.F90     (icepack_step_therm1, icepack_step_therm2, icepack_prep_radiation, 
+  ice_step_mod.F90     (icepack_step_therm1, icepack_step_therm2, icepack_prep_radiation,
                         icepack_step_radiation, icepack_step_ridge)
diff --git a/cicecore/version.txt b/cicecore/version.txt
index 4efe718e0..cef257940 100644
--- a/cicecore/version.txt
+++ b/cicecore/version.txt
@@ -1 +1 @@
-CICE 6.6.2
+CICE 6.6.3
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 458d72887..fa93c8a1a 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -57,7 +57,7 @@
 
 # General information about the project.
 project = u'CICE'
-copyright = u'1998-2025, Triad National Security, LLC (code) and National Center for Atmospheric Research (documentation)'
+copyright = u'1998-2026, Triad National Security, LLC (code) and National Center for Atmospheric Research (documentation)'
 author = u'CICE-Consortium'
 
 # The version info for the project you're documenting, acts as replacement for
@@ -65,9 +65,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = u'6.6.2' 
+version = u'6.6.3' 
 # The full version, including alpha/beta/rc tags.
-version = u'6.6.2' 
+version = u'6.6.3' 
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/icepack b/icepack
index 0bcde2556..2f31ee37f 160000
--- a/icepack
+++ b/icepack
@@ -1 +1 @@
-Subproject commit 0bcde255637a5947b1b7a4e4fc8dccd77803cb65
+Subproject commit 2f31ee37f3a70a70b5e33cae43476f09dbb33da7