diff --git a/bld/namelist_files/namelist_defaults_ctsm.xml b/bld/namelist_files/namelist_defaults_ctsm.xml
index 650b21cb8d..8746319186 100644
--- a/bld/namelist_files/namelist_defaults_ctsm.xml
+++ b/bld/namelist_files/namelist_defaults_ctsm.xml
@@ -1101,7 +1101,6 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 </init_interp_attributes>
 
 
-
 <!-- matches for clm5_0 physics with CAM6.0 -->
 <init_interp_attributes sim_year="2000" use_cndv=".false." use_fates=".false." lnd_tuning_mode="clm5_0_cam6.0"
                         hgrid="0.9x1.25"
@@ -1274,6 +1273,7 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 >hgrid=ne0np4CONUS.ne30x8 maxpft=17 mask=tx0.1v2 use_cn=.false. use_crop=.false. irrigate=.true. glc_nec=10 do_transient_pfts=.false. use_excess_ice=.false.
 </init_interp_attributes>
 
+
 <!--
      1850 preindustrial IC (if use_init_interp is added and set to .true. then MUST still interpolate even on an exact match)
                            (if it will work on an exact match, leave use_init_interp off)
@@ -2036,6 +2036,10 @@ lnd/clm2/surfdata_esmf/NEON/ctsm5.3.0/surfdata_1x1_NEON_TOOL_hist_2000_78pfts_c2
  >lnd/clm2/surfdata_esmf/ctsm5.3.0/landuse.timeseries_0.9x1.25_SSP2-4.5_1850-2100_78pfts_c240908.nc</flanduse_timeseries>
 <flanduse_timeseries hgrid="1.9x2.5"       sim_year_range="1850-2000"
  >lnd/clm2/surfdata_esmf/ctsm5.3.0/landuse.timeseries_1.9x2.5_SSP2-4.5_1850-2100_78pfts_c240908.nc</flanduse_timeseries>
+<flanduse_timeseries hgrid="ne0np4.ARCTIC.ne30x4" sim_year_range="1850-2000"
+>lnd/clm2/surfdata_esmf/ctsm5.3.0/landuse.timeseries_ne0np4.ARCTIC.ne30x4_SSP2-4.5_1979-2026_78pfts_c240908.nc</flanduse_timeseries>
+<flanduse_timeseries hgrid="ne0np4CONUS.ne30x8" sim_year_range="1850-2000"
+>lnd/clm2/surfdata_esmf/ctsm5.3.0/landuse.timeseries_ne0np4CONUS.ne30x8_SSP2-4.5_1979-2026_78pfts_c240908.nc</flanduse_timeseries>
 <!-- Do we need both use_crop=".false." and ".true." for FATES transient? -->
 <!-- As of 2024/02/02 the Grids Support spreadsheet includes no 16-pft landuse files. -->
 <flanduse_timeseries hgrid="4x5"           sim_year_range="1850-2000"
diff --git a/bld/unit_testers/build-namelist_test.pl b/bld/unit_testers/build-namelist_test.pl
index 06c9bcc361..4f03ed089f 100755
--- a/bld/unit_testers/build-namelist_test.pl
+++ b/bld/unit_testers/build-namelist_test.pl
@@ -514,6 +514,9 @@ sub cat_and_create_namelistinfile {
    foreach my $options (
                       "--res 1.9x2.5 --mask gx1v7 --bgc sp --use_case 20thC_transient --namelist '&a start_ymd=19790101/' --lnd_tuning_mode ${phys}_cam6.0 --infile empty_user_nl_clm",
                       "--res 1.9x2.5 --mask gx1v7 --bgc sp --use_case 20thC_transient --namelist '&a start_ymd=19790101/' --lnd_tuning_mode ${phys}_cam7.0 --infile empty_user_nl_clm",
+                      "--res 1.9x2.5 --mask gx1v7 --bgc sp -no-crop --use_case 20thC_transient --namelist '&a start_ymd=19790101/' --lnd_tuning_mode ${phys}_cam7.0 --infile empty_user_nl_clm",
+                      "--res ne0np4.ARCTIC.ne30x4 --mask tx0.1v2 -bgc sp -use_case 20thC_transient -namelist '&a start_ymd=19790101/' -lnd_tuning_mode ${phys}_cam7.0 --infile empty_user_nl_clm",
+                      "--res ne0np4CONUS.ne30x8 --mask tx0.1v2 -bgc sp -use_case 20thC_transient -namelist '&a start_ymd=20130101/' -lnd_tuning_mode ${phys}_cam7.0 --infile empty_user_nl_clm",
                      ) {
       &make_env_run( 'LND_SETS_DUST_EMIS_DRV_FLDS'=>"FALSE" );
       eval{ system( "$bldnml --envxml_dir . $options > $tempfile 2>&1 " ); };
diff --git a/cime_config/testdefs/testlist_clm.xml b/cime_config/testdefs/testlist_clm.xml
index 490748c7e7..77a2d76ba3 100644
--- a/cime_config/testdefs/testlist_clm.xml
+++ b/cime_config/testdefs/testlist_clm.xml
@@ -2015,7 +2015,17 @@
       <option name="comment"  >Also --nofireemis because this is a SP compset</option>
     </options>
   </test>
-  <test name="SMS_Ln9" grid="ne0ARCTICne30x4_ne0ARCTICne30x4_mt12" compset="IHistClm60Sp" testmods="clm/clm60cam7LndTuningMode_1979Start--clm/nofireemis">
+  <test name="SMS_Ln9" grid="f19_f19_mg17" compset="IHistClm50Sp" testmods="clm/clm50cam7LndTuningMode_1979Start--clm/nofireemis">
+    <machines>
+      <machine name="derecho" compiler="intel" category="aux_clm"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:20:00</option>
+      <option name="comment"  >Run f19 for the same as the ne0ARCTIC case starting in 1979"</option>
+      <option name="comment"  >Also --nofireemis because this is a SP compset</option>
+    </options>
+  </test>
+  <test name="SMS_Ln9" grid="ne0ARCTICne30x4_ne0ARCTICne30x4_mt12" compset="IHistClm50Sp" testmods="clm/clm50cam7LndTuningMode_1979Start--clm/nofireemis">
     <machines>
       <machine name="derecho" compiler="intel" category="ctsm_sci"/>
     </machines>
@@ -2025,6 +2035,16 @@
       <option name="comment"  >Also --nofireemis because this is a SP compset</option>
     </options>
   </test>
+  <test name="SMS_Ln9" grid="ne0ARCTICne30x4_ne0ARCTICne30x4_mt12" compset="IHistClm60Sp" testmods="clm/clm60cam7LndTuningMode_1979Start--clm/nofireemis">
+    <machines>
+      <machine name="derecho" compiler="intel" category="ctsm_sci"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:20:00</option>
+      <option name="comment"  >Repeat ARCTIC transient starting in 1979 for Clm60"</option>
+      <option name="comment"  >Also --nofireemis because this is a SP compset</option>
+    </options>
+  </test>
   <test name="SMS_Ln9" grid="ne0ARCTICGRISne30x8_ne0ARCTICGRISne30x8_mt12" compset="IHistClm60Sp" testmods="clm/clm60cam7LndTuningMode_1979Start--clm/nofireemis">
     <machines>
       <machine name="derecho" compiler="intel" category="ctsm_sci"/>
@@ -2044,7 +2064,7 @@
       <option name="comment"  >Run ARCTICGRIS for 1850 case (do not run this expensive test with every tag, but include it in the less frequent ctsm_sci testing)"</option>
     </options>
   </test>
-  <test name="SMS_Ln9" grid="ne0CONUSne30x8_ne0CONUSne30x8_mt12" compset="IHistClm60Sp" testmods="clm/clm60cam7LndTuningMode_2013Start--clm/nofireemis">
+  <test name="SMS_Ln9" grid="ne0CONUSne30x8_ne0CONUSne30x8_mt12" compset="IHistClm50Sp" testmods="clm/clm50cam7LndTuningMode_2013Start--clm/nofireemis">
     <machines>
       <machine name="derecho" compiler="intel" category="ctsm_sci"/>
     </machines>
@@ -2054,6 +2074,16 @@
       <option name="comment"  >Also --nofireemis because this is a SP compset</option>
     </options>
   </test>
+  <test name="SMS_Ln9" grid="ne0CONUSne30x8_ne0CONUSne30x8_mt12" compset="IHistClm60Sp" testmods="clm/clm60cam7LndTuningMode_2013Start--clm/nofireemis">
+    <machines>
+      <machine name="derecho" compiler="intel" category="ctsm_sci"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:20:00</option>
+      <option name="comment"  >Repeat CONUS transient starting in 2013 for Clm60"</option>
+      <option name="comment"  >Also --nofireemis because this is a SP compset</option>
+    </options>
+  </test>
   <!-- Historical science support for clm5_0 workhorse resolutions -->
   <test name="SMS_Ld5" grid="f09_g17" compset="IHistClm50Sp" testmods="clm/nofire">
     <machines>
diff --git a/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode/include_user_mods b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode/include_user_mods
new file mode 100644
index 0000000000..fe0e18cf88
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode/include_user_mods
@@ -0,0 +1 @@
+../default
diff --git a/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode/shell_commands b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode/shell_commands
new file mode 100644
index 0000000000..a9b56a5eae
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode/shell_commands
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+./xmlchange LND_TUNING_MODE="clm5_0_cam7.0"
+./xmlchange ROF_NCPL='$ATM_NCPL'
+
diff --git a/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_1979Start/include_user_mods b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_1979Start/include_user_mods
new file mode 100644
index 0000000000..44d94c8805
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_1979Start/include_user_mods
@@ -0,0 +1 @@
+../clm50cam7LndTuningMode
diff --git a/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_1979Start/shell_commands b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_1979Start/shell_commands
new file mode 100644
index 0000000000..2aafcc1186
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_1979Start/shell_commands
@@ -0,0 +1 @@
+./xmlchange RUN_STARTDATE=1979-01-01
diff --git a/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_2013Start/include_user_mods b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_2013Start/include_user_mods
new file mode 100644
index 0000000000..44d94c8805
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_2013Start/include_user_mods
@@ -0,0 +1 @@
+../clm50cam7LndTuningMode
diff --git a/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_2013Start/shell_commands b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_2013Start/shell_commands
new file mode 100644
index 0000000000..035842f982
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/clm/clm50cam7LndTuningMode_2013Start/shell_commands
@@ -0,0 +1 @@
+./xmlchange RUN_STARTDATE=2013-01-01