diff --git a/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml b/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml
index 4069eb144cff..fd915fb38278 100644
--- a/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml
+++ b/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml
@@ -49,6 +49,7 @@
 <config_dt ocn_grid="SOwISC12to60E2r4">'00:10:00'</config_dt>
 <config_dt ocn_grid="ECwISC30to60E2r1">'00:30:00'</config_dt>
 <config_dt ocn_grid="IcoswISC30E3r5">'00:30:00'</config_dt>
+<config_dt ocn_grid="IcosXISC30E3r7">'00:30:00'</config_dt>
 <config_time_integrator>'split_explicit_ab2'</config_time_integrator>
 <config_number_of_time_levels>2</config_number_of_time_levels>
 
@@ -73,6 +74,7 @@
 <config_hmix_scaleWithMesh ocn_grid="SOwISC12to60E2r4">.true.</config_hmix_scaleWithMesh>
 <config_hmix_scaleWithMesh ocn_grid="ECwISC30to60E2r1">.true.</config_hmix_scaleWithMesh>
 <config_hmix_scaleWithMesh ocn_grid="IcoswISC30E3r5">.true.</config_hmix_scaleWithMesh>
+<config_hmix_scaleWithMesh ocn_grid="IcosXISC30E3r7">.true.</config_hmix_scaleWithMesh>
 <config_maxMeshDensity>-1.0</config_maxMeshDensity>
 <config_hmix_use_ref_cell_width>.false.</config_hmix_use_ref_cell_width>
 <config_hmix_ref_cell_width>30.0e3</config_hmix_ref_cell_width>
@@ -89,6 +91,7 @@
 <config_use_mom_del2 ocn_grid="SOwISC12to60E2r4">.true.</config_use_mom_del2>
 <config_use_mom_del2 ocn_grid="ECwISC30to60E2r1">.true.</config_use_mom_del2>
 <config_use_mom_del2 ocn_grid="IcoswISC30E3r5">.true.</config_use_mom_del2>
+<config_use_mom_del2 ocn_grid="IcosXISC30E3r7">.true.</config_use_mom_del2>
 <config_mom_del2>10.0</config_mom_del2>
 <config_mom_del2 ocn_grid="oEC60to30v3">1000.0</config_mom_del2>
 <config_mom_del2 ocn_grid="oEC60to30v3wLI">1000.0</config_mom_del2>
@@ -99,6 +102,7 @@
 <config_mom_del2 ocn_grid="SOwISC12to60E2r4">462.0</config_mom_del2>
 <config_mom_del2 ocn_grid="ECwISC30to60E2r1">1000.0</config_mom_del2>
 <config_mom_del2 ocn_grid="IcoswISC30E3r5">1000.0</config_mom_del2>
+<config_mom_del2 ocn_grid="IcosXISC30E3r7">1000.0</config_mom_del2>
 <config_use_tracer_del2>.false.</config_use_tracer_del2>
 <config_tracer_del2>10.0</config_tracer_del2>
 
@@ -124,6 +128,7 @@
 <config_mom_del4 ocn_grid="SOwISC12to60E2r4">1.18e10</config_mom_del4>
 <config_mom_del4 ocn_grid="ECwISC30to60E2r1">1.2e11</config_mom_del4>
 <config_mom_del4 ocn_grid="IcoswISC30E3r5">1.2e11</config_mom_del4>
+<config_mom_del4 ocn_grid="IcosXISC30E3r7">1.2e11</config_mom_del4>
 <config_mom_del4_div_factor>1.0</config_mom_del4_div_factor>
 <config_use_tracer_del4>.false.</config_use_tracer_del4>
 <config_tracer_del4>0.0</config_tracer_del4>
@@ -156,6 +161,7 @@
 <config_Redi_horizontal_taper ocn_grid="ECwISC30to60E2r1">'RossbyRadius'</config_Redi_horizontal_taper>
 <!-- To do: ramp for WC but RossbyRadius for Cryo -->
 <config_Redi_horizontal_taper ocn_grid="IcoswISC30E3r5">'ramp'</config_Redi_horizontal_taper>
+<config_Redi_horizontal_taper ocn_grid="IcosXISC30E3r7">'ramp'</config_Redi_horizontal_taper>
 <config_Redi_horizontal_ramp_min>20e3</config_Redi_horizontal_ramp_min>
 <config_Redi_horizontal_ramp_min ocn_grid="WCAtl12to45E2r4">30e3</config_Redi_horizontal_ramp_min>
 <config_Redi_horizontal_ramp_max>30e3</config_Redi_horizontal_ramp_max>
@@ -182,6 +188,7 @@
 <config_GM_closure ocn_grid="ECwISC30to60E2r1">'N2_dependent'</config_GM_closure>
 <!-- To do: constant for WC but N2_dependent for Cryo -->
 <config_GM_closure ocn_grid="IcoswISC30E3r5">'constant'</config_GM_closure>
+<config_GM_closure ocn_grid="IcosXISC30E3r7">'constant'</config_GM_closure>
 <config_GM_constant_kappa>900.0</config_GM_constant_kappa>
 <config_GM_constant_kappa ocn_forcing="datm_forced_restoring" ocn_grid="oEC60to30v3wLI">600.0</config_GM_constant_kappa>
 <config_GM_constant_kappa ocn_forcing="datm_forced_restoring" ocn_grid="ECwISC30to60E1r2">600.0</config_GM_constant_kappa>
@@ -191,6 +198,7 @@
 <config_GM_constant_kappa ocn_forcing="datm_forced_restoring" ocn_grid="SOwISC12to60E2r4">600.0</config_GM_constant_kappa>
 <config_GM_constant_kappa ocn_forcing="datm_forced_restoring" ocn_grid="ECwISC30to60E2r1">600.0</config_GM_constant_kappa>
 <config_GM_constant_kappa ocn_forcing="datm_forced_restoring" ocn_grid="IcoswISC30E3r5">600.0</config_GM_constant_kappa>
+<config_GM_constant_kappa ocn_forcing="datm_forced_restoring" ocn_grid="IcosXISC30E3r7">600.0</config_GM_constant_kappa>
 <config_GM_constant_bclModeSpeed>0.3</config_GM_constant_bclModeSpeed>
 <config_GM_minBclModeSpeed_method>'constant'</config_GM_minBclModeSpeed_method>
 <config_GM_spatially_variable_min_kappa>300.0</config_GM_spatially_variable_min_kappa>
@@ -200,6 +208,7 @@
 <config_GM_spatially_variable_baroclinic_mode ocn_grid="ECwISC30to60E2r1">1.0</config_GM_spatially_variable_baroclinic_mode>
 <!-- To do: 3.0 for WC but 1.0 for Cryo? -->
 <config_GM_spatially_variable_baroclinic_mode ocn_grid="IcoswISC30E3r5">3.0</config_GM_spatially_variable_baroclinic_mode>
+<config_GM_spatially_variable_baroclinic_mode ocn_grid="IcosXISC30E3r7">3.0</config_GM_spatially_variable_baroclinic_mode>
 <config_GM_Visbeck_alpha>0.13</config_GM_Visbeck_alpha>
 <config_GM_Visbeck_max_depth>1000.0</config_GM_Visbeck_max_depth>
 <config_GM_EG_riMin>200.0</config_GM_EG_riMin>
@@ -211,6 +220,7 @@
 <config_GM_horizontal_taper ocn_grid="ECwISC30to60E2r1">'RossbyRadius'</config_GM_horizontal_taper>
 <!-- To do: ramp for WC but RossbyRadius for Cryo -->
 <config_GM_horizontal_taper ocn_grid="IcoswISC30E3r5">'ramp'</config_GM_horizontal_taper>
+<config_GM_horizontal_taper ocn_grid="IcosXISC30E3r7">'ramp'</config_GM_horizontal_taper>
 <config_GM_horizontal_ramp_min>20e3</config_GM_horizontal_ramp_min>
 <config_GM_horizontal_ramp_min ocn_grid="WCAtl12to45E2r4">30e3</config_GM_horizontal_ramp_min>
 <config_GM_horizontal_ramp_max>30e3</config_GM_horizontal_ramp_max>
@@ -347,6 +357,7 @@
 <config_land_ice_flux_mode ocn_grid="SOwISC12to60E2r4">'pressure_only'</config_land_ice_flux_mode>
 <config_land_ice_flux_mode ocn_grid="ECwISC30to60E2r1">'pressure_only'</config_land_ice_flux_mode>
 <config_land_ice_flux_mode ocn_grid="IcoswISC30E3r5">'pressure_only'</config_land_ice_flux_mode>
+<config_land_ice_flux_mode ocn_grid="IcosXISC30E3r7">'pressure_only'</config_land_ice_flux_mode>
 <config_land_ice_flux_formulation>'Jenkins'</config_land_ice_flux_formulation>
 <config_land_ice_flux_useHollandJenkinsAdvDiff>.false.</config_land_ice_flux_useHollandJenkinsAdvDiff>
 <config_land_ice_flux_attenuation_coefficient>10.0</config_land_ice_flux_attenuation_coefficient>
@@ -360,6 +371,7 @@
 <config_land_ice_flux_explicit_topDragCoeff ocn_grid="SOwISC12to60E2r4">4.48e-3</config_land_ice_flux_explicit_topDragCoeff>
 <config_land_ice_flux_explicit_topDragCoeff ocn_grid="ECwISC30to60E2r1">4.48e-3</config_land_ice_flux_explicit_topDragCoeff>
 <config_land_ice_flux_explicit_topDragCoeff ocn_grid="IcoswISC30E3r5">4.48e-3</config_land_ice_flux_explicit_topDragCoeff>
+<config_land_ice_flux_explicit_topDragCoeff ocn_grid="IcosXISC30E3r7">4.48e-3</config_land_ice_flux_explicit_topDragCoeff>
 <config_land_ice_flux_ISOMIP_gammaT>1e-4</config_land_ice_flux_ISOMIP_gammaT>
 <config_land_ice_flux_rms_tidal_velocity>5e-2</config_land_ice_flux_rms_tidal_velocity>
 <config_land_ice_flux_jenkins_heat_transfer_coefficient>0.011</config_land_ice_flux_jenkins_heat_transfer_coefficient>
@@ -368,12 +380,14 @@
 <config_land_ice_flux_jenkins_heat_transfer_coefficient ocn_grid="SOwISC12to60E2r4">0.00295</config_land_ice_flux_jenkins_heat_transfer_coefficient>
 <config_land_ice_flux_jenkins_heat_transfer_coefficient ocn_grid="ECwISC30to60E2r1">0.00295</config_land_ice_flux_jenkins_heat_transfer_coefficient>
 <config_land_ice_flux_jenkins_heat_transfer_coefficient ocn_grid="IcoswISC30E3r5">0.00295</config_land_ice_flux_jenkins_heat_transfer_coefficient>
+<config_land_ice_flux_jenkins_heat_transfer_coefficient ocn_grid="IcosXISC30E3r7">0.00295</config_land_ice_flux_jenkins_heat_transfer_coefficient>
 <config_land_ice_flux_jenkins_salt_transfer_coefficient>3.1e-4</config_land_ice_flux_jenkins_salt_transfer_coefficient>
 <config_land_ice_flux_jenkins_salt_transfer_coefficient ocn_grid="oEC60to30v3wLI">8.42e-5</config_land_ice_flux_jenkins_salt_transfer_coefficient>
 <config_land_ice_flux_jenkins_salt_transfer_coefficient ocn_grid="ECwISC30to60E1r2">8.42e-5</config_land_ice_flux_jenkins_salt_transfer_coefficient>
 <config_land_ice_flux_jenkins_salt_transfer_coefficient ocn_grid="SOwISC12to60E2r4">8.42e-5</config_land_ice_flux_jenkins_salt_transfer_coefficient>
 <config_land_ice_flux_jenkins_salt_transfer_coefficient ocn_grid="ECwISC30to60E2r1">8.42e-5</config_land_ice_flux_jenkins_salt_transfer_coefficient>
 <config_land_ice_flux_jenkins_salt_transfer_coefficient ocn_grid="IcoswISC30E3r5">8.42e-5</config_land_ice_flux_jenkins_salt_transfer_coefficient>
+<config_land_ice_flux_jenkins_salt_transfer_coefficient ocn_grid="IcosXISC30E3r7">8.42e-5</config_land_ice_flux_jenkins_salt_transfer_coefficient>
 
 <!-- advection -->
 <config_vert_advection_method>'flux-form'</config_vert_advection_method>
@@ -397,6 +411,7 @@
 <config_implicit_top_drag_coeff ocn_grid="SOwISC12to60E2r4">4.48e-3</config_implicit_top_drag_coeff>
 <config_implicit_top_drag_coeff ocn_grid="ECwISC30to60E2r1">4.48e-3</config_implicit_top_drag_coeff>
 <config_implicit_top_drag_coeff ocn_grid="IcoswISC30E3r5">4.48e-3</config_implicit_top_drag_coeff>
+<config_implicit_top_drag_coeff ocn_grid="IcosXISC30E3r7">4.48e-3</config_implicit_top_drag_coeff>
 <config_loglaw_bottom_roughness>1.0e-3</config_loglaw_bottom_roughness>
 <config_loglaw_layer_depth_max>10.0</config_loglaw_layer_depth_max>
 <config_loglaw_bottom_drag_min>2.5e-3</config_loglaw_bottom_drag_min>
@@ -475,6 +490,7 @@
 <config_btr_dt ocn_grid="SOwISC12to60E2r4">'0000_00:00:15'</config_btr_dt>
 <config_btr_dt ocn_grid="ECwISC30to60E2r1">'0000_00:01:15'</config_btr_dt>
 <config_btr_dt ocn_grid="IcoswISC30E3r5">'0000_00:01:00'</config_btr_dt>
+<config_btr_dt ocn_grid="IcosXISC30E3r7">'0000_00:01:00'</config_btr_dt>
 <config_n_btr_cor_iter>2</config_n_btr_cor_iter>
 <config_vel_correction>.true.</config_vel_correction>
 <config_btr_subcycle_loop_factor>2</config_btr_subcycle_loop_factor>
@@ -516,6 +532,7 @@
 <config_check_ssh_consistency ocn_grid="SOwISC12to60E2r4">.false.</config_check_ssh_consistency>
 <config_check_ssh_consistency ocn_grid="ECwISC30to60E2r1">.false.</config_check_ssh_consistency>
 <config_check_ssh_consistency ocn_grid="IcoswISC30E3r5">.false.</config_check_ssh_consistency>
+<config_check_ssh_consistency ocn_grid="IcosXISC30E3r7">.false.</config_check_ssh_consistency>
 <config_filter_btr_mode>.false.</config_filter_btr_mode>
 <config_prescribe_velocity>.false.</config_prescribe_velocity>
 <config_prescribe_thickness>.false.</config_prescribe_thickness>
@@ -1033,6 +1050,7 @@
 <config_AM_mocStreamfunction_enable ocn_grid="SOwISC12to60E2r4">.true.</config_AM_mocStreamfunction_enable>
 <config_AM_mocStreamfunction_enable ocn_grid="ECwISC30to60E2r1">.true.</config_AM_mocStreamfunction_enable>
 <config_AM_mocStreamfunction_enable ocn_grid="IcoswISC30E3r5">.true.</config_AM_mocStreamfunction_enable>
+<config_AM_mocStreamfunction_enable ocn_grid="IcosXISC30E3r7">.true.</config_AM_mocStreamfunction_enable>
 <config_AM_mocStreamfunction_compute_interval>'0000-00-00_01:00:00'</config_AM_mocStreamfunction_compute_interval>
 <config_AM_mocStreamfunction_output_stream>'mocStreamfunctionOutput'</config_AM_mocStreamfunction_output_stream>
 <config_AM_mocStreamfunction_compute_on_startup>.true.</config_AM_mocStreamfunction_compute_on_startup>
@@ -1115,16 +1133,19 @@
 <config_AM_conservationCheck_enable ocn_grid="SOwISC12to60E2r4">.true.</config_AM_conservationCheck_enable>
 <config_AM_conservationCheck_enable ocn_grid="ECwISC30to60E2r1">.true.</config_AM_conservationCheck_enable>
 <config_AM_conservationCheck_enable ocn_grid="IcoswISC30E3r5">.true.</config_AM_conservationCheck_enable>
+<config_AM_conservationCheck_enable ocn_grid="IcosXISC30E3r7">.true.</config_AM_conservationCheck_enable>
 <config_AM_conservationCheck_compute_interval>'dt'</config_AM_conservationCheck_compute_interval>
 <config_AM_conservationCheck_output_stream>'conservationCheckOutput'</config_AM_conservationCheck_output_stream>
 <config_AM_conservationCheck_compute_on_startup>.false.</config_AM_conservationCheck_compute_on_startup>
 <config_AM_conservationCheck_compute_on_startup ocn_grid="SOwISC12to60E2r4">.true.</config_AM_conservationCheck_compute_on_startup>
 <config_AM_conservationCheck_compute_on_startup ocn_grid="ECwISC30to60E2r1">.true.</config_AM_conservationCheck_compute_on_startup>
 <config_AM_conservationCheck_compute_on_startup ocn_grid="IcoswISC30E3r5">.true.</config_AM_conservationCheck_compute_on_startup>
+<config_AM_conservationCheck_compute_on_startup ocn_grid="IcosXISC30E3r7">.true.</config_AM_conservationCheck_compute_on_startup>
 <config_AM_conservationCheck_write_on_startup>.false.</config_AM_conservationCheck_write_on_startup>
 <config_AM_conservationCheck_write_on_startup ocn_grid="SOwISC12to60E2r4">.true.</config_AM_conservationCheck_write_on_startup>
 <config_AM_conservationCheck_write_on_startup ocn_grid="ECwISC30to60E2r1">.true.</config_AM_conservationCheck_write_on_startup>
 <config_AM_conservationCheck_write_on_startup ocn_grid="IcoswISC30E3r5">.true.</config_AM_conservationCheck_write_on_startup>
+<config_AM_conservationCheck_write_on_startup ocn_grid="IcosXISC30E3r7">.true.</config_AM_conservationCheck_write_on_startup>
 <config_AM_conservationCheck_write_to_logfile>.true.</config_AM_conservationCheck_write_to_logfile>
 <config_AM_conservationCheck_restart_stream>'conservationCheckRestart'</config_AM_conservationCheck_restart_stream>
 
diff --git a/components/mpas-ocean/cime_config/buildnml b/components/mpas-ocean/cime_config/buildnml
index 4dd4c228d484..06ef7f34b74f 100755
--- a/components/mpas-ocean/cime_config/buildnml
+++ b/components/mpas-ocean/cime_config/buildnml
@@ -300,6 +300,17 @@ def buildnml(case, caseroot, compname):
         if ocn_ismf == 'data':
             data_ismf_file = 'prescribed_ismf_adusumilli2020.IcoswISC30E3r5.20231120.nc'
 
+    elif ocn_grid == 'IcosXISC30E3r7':
+        decomp_date = '20240314'
+        decomp_prefix = 'partitions/mpas-o.graph.info.'
+        restoring_file = 'sss.PHC2_monthlyClimatology.IcosXISC30E3r7.20240314.nc'
+        analysis_mask_file = 'IcosXISC30E3r7_mocBasinsAndTransects20210623.nc'
+        ic_date = '20240314'
+        ic_prefix = 'mpaso.IcosXISC30E3r7'
+        if ocn_ic_mode == 'spunup':
+            ic_date = '20240314'
+            ic_prefix = 'mpaso.IcosXISC30E3r7.rstFromPiControlSpinup-chrysalis'
+
     #--------------------------------------------------------------------
     # Set OCN_FORCING = datm_forced_restoring if restoring file is available
     #--------------------------------------------------------------------
diff --git a/components/mpas-seaice/bld/namelist_files/namelist_defaults_mpassi.xml b/components/mpas-seaice/bld/namelist_files/namelist_defaults_mpassi.xml
index 1414ffc777de..64f93a281f0a 100644
--- a/components/mpas-seaice/bld/namelist_files/namelist_defaults_mpassi.xml
+++ b/components/mpas-seaice/bld/namelist_files/namelist_defaults_mpassi.xml
@@ -25,6 +25,7 @@
 <config_dt ice_grid="SOwISC12to60E2r4">1800.0</config_dt>
 <config_dt ice_grid="ECwISC30to60E2r1">1800.0</config_dt>
 <config_dt ice_grid="IcoswISC30E3r5">1800.0</config_dt>
+<config_dt ice_grid="IcosXISC30E3r7">1800.0</config_dt>
 <config_calendar_type>'noleap'</config_calendar_type>
 <config_start_time>'2000-01-01_00:00:00'</config_start_time>
 <config_stop_time>'none'</config_stop_time>
@@ -77,6 +78,7 @@
 <config_initial_latitude_north ice_grid="ECwISC30to60E2r1">75.0</config_initial_latitude_north>
 <!-- To do: 70.0 for WC but 75.0 for Cryo -->
 <config_initial_latitude_north ice_grid="IcoswISC30E3r5">70.0</config_initial_latitude_north>
+<config_initial_latitude_north ice_grid="IcosXISC30E3r7">70.0</config_initial_latitude_north>
 <config_initial_latitude_north ice_grid="ARRM10to60E2r1">75.0</config_initial_latitude_north>
 <config_initial_latitude_north ice_grid="oRRS30to10v3wLI">85.0</config_initial_latitude_north>
 <config_initial_latitude_north ice_grid="oRRS18to6v3">85.0</config_initial_latitude_north>
@@ -87,6 +89,7 @@
 <config_initial_latitude_south ice_grid="ECwISC30to60E2r1">-75.0</config_initial_latitude_south>
 <!-- To do: -60.0 for WC but -75.0 for Cryo -->
 <config_initial_latitude_south ice_grid="IcoswISC30E3r5">-60.0</config_initial_latitude_south>
+<config_initial_latitude_south ice_grid="IcosXISC30E3r7">-60.0</config_initial_latitude_south>
 <config_initial_latitude_south ice_grid="ARRM10to60E2r1">-85.0</config_initial_latitude_south>
 <config_initial_latitude_south ice_grid="oRRS30to10v3wLI">-85.0</config_initial_latitude_south>
 <config_initial_latitude_south ice_grid="oRRS18to6v3">-85.0</config_initial_latitude_south>
@@ -148,6 +151,7 @@
 <config_dynamics_subcycle_number ice_grid="SOwISC12to60E2r4">1</config_dynamics_subcycle_number>
 <config_dynamics_subcycle_number ice_grid="ECwISC30to60E2r1">1</config_dynamics_subcycle_number>
 <config_dynamics_subcycle_number ice_grid="IcoswISC30E3r5">1</config_dynamics_subcycle_number>
+<config_dynamics_subcycle_number ice_grid="IcosXISC30E3r7">1</config_dynamics_subcycle_number>
 <config_rotate_cartesian_grid>true</config_rotate_cartesian_grid>
 <config_include_metric_terms>true</config_include_metric_terms>
 <config_elastic_subcycle_number>120</config_elastic_subcycle_number>
diff --git a/components/mpas-seaice/cime_config/buildnml b/components/mpas-seaice/cime_config/buildnml
index cbb6109018e2..0156774f17a2 100755
--- a/components/mpas-seaice/cime_config/buildnml
+++ b/components/mpas-seaice/cime_config/buildnml
@@ -267,6 +267,16 @@ def buildnml(case, caseroot, compname):
                 grid_date = '20231121'
                 grid_prefix = 'mpassi.IcoswISC30E3r5.rstFromG-chrysalis'
 
+    elif ice_grid == 'IcosXISC30E3r7':
+        grid_date = '20240314'
+        grid_prefix = 'mpassi.IcosXISC30E3r7'
+        decomp_date = '20240314'
+        decomp_prefix = 'partitions/mpas-seaice.graph.info.'
+        data_iceberg_file = 'Iceberg_Climatology_Merino.IcosXISC30E3r7.20240314.nc'
+        if ice_ic_mode == 'spunup':
+            grid_date = '20240314'
+            grid_prefix = 'mpassi.IcosXISC30E3r7.rstFromPiControlSpinup-chrysalis'
+
     elif ice_grid == 'ICOS10':
         grid_date = '211015'
         grid_prefix = 'seaice.ICOS10'