diff --git a/components/elm/bld/namelist_files/namelist_definition.xml b/components/elm/bld/namelist_files/namelist_definition.xml
index c08951338d74..dfa4a86ac741 100644
--- a/components/elm/bld/namelist_files/namelist_definition.xml
+++ b/components/elm/bld/namelist_files/namelist_definition.xml
@@ -1424,7 +1424,7 @@ Representative concentration pathway for future scenarios [radiative forcing at
+ valid_values="USGS,gx3v7,gx1v6,navy,test,tx0.1v2,tx1v1,T62,TL319,cruncep,oEC60to30v3,oEC60to30v3wLI,ECwISC30to60E1r2,EC30to60E2r2,WC14to60E2r3,WCAtl12to45E2r4,SOwISC12to60E2r4,ECwISC30to60E2r1,oRRS18to6,oRRS18to6v3,oRRS15to5,oARRM60to10,oARRM60to6,ARRM10to60E2r1,oQU480,oQU240,oQU240wLI,oQU120,oRRS30to10v3,oRRS30to10v3wLI,360x720cru,NLDASww3a,NLDAS,tx0.1v2,ICOS10,IcoswISC30E3r5,RRS6to18E3r6">
Land mask description
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 6541b9a5a2be..836eb0dcfbde 100644
--- a/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml
+++ b/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml
@@ -53,6 +53,7 @@
'00:04:00'
'00:02:00'
'00:01:00'
+'00:05:00'
'split_explicit_ab2'
2
@@ -81,6 +82,7 @@
.true.
.true.
.true.
+.true.
-1.0
.false.
30.0e3
@@ -144,6 +146,7 @@
4.37e08
5.46e07
6.83e06
+3.2e09
1.0
.false.
0.0
@@ -160,6 +163,7 @@
.false.
.false.
.false.
+.false.
'constant'
400.0
400.0
@@ -197,6 +201,7 @@
.false.
.false.
.false.
+.false.
'EdenGreatbatch'
'constant'
'constant'
@@ -535,6 +540,7 @@
'0000_00:00:05'
'0000_00:00:02.5'
'0000_00:00:01.25'
+'0000_00:00:10'
2
.true.
2
@@ -1101,6 +1107,7 @@
.true.
.true.
.true.
+.true.
'0000-00-00_01:00:00'
'mocStreamfunctionOutput'
.true.
@@ -1187,6 +1194,7 @@
.true.
.true.
.true.
+.true.
'dt'
'conservationCheckOutput'
.false.
@@ -1197,6 +1205,7 @@
.true.
.true.
.true.
+.true.
.false.
.true.
.true.
@@ -1205,6 +1214,7 @@
.true.
.true.
.true.
+.true.
.true.
'conservationCheckRestart'
diff --git a/components/mpas-ocean/cime_config/buildnml b/components/mpas-ocean/cime_config/buildnml
index 048e621fafad..85ca02b9e91f 100755
--- a/components/mpas-ocean/cime_config/buildnml
+++ b/components/mpas-ocean/cime_config/buildnml
@@ -352,6 +352,18 @@ def buildnml(case, caseroot, compname):
if ocn_ismf == 'data':
data_ismf_file = 'prescribed_ismf_paolo2023.IcoswISC30E3r5.20240227.nc'
+ elif ocn_grid == 'RRS6to18E3r6':
+ decomp_date = '20240404'
+ decomp_prefix = 'partitions/mpas-o.graph.info.'
+ restoring_file = 'sss.PHC2_monthlyClimatology.RRS6to18E3r6.20240402.nc'
+ analysis_mask_file = 'RRS6to18E3r6_mocBasinsAndTransects20210623.nc'
+ ic_date = '20240402'
+ ic_prefix = 'mpaso.RRS6to18E3r6'
+ if ocn_ic_mode == 'spunup':
+ logger.warning("WARNING: The specified compset is requesting ocean ICs spunup from a G-case")
+ logger.warning(" But no file available for this grid.")
+
+
#--------------------------------------------------------------------
# Set OCN_FORCING = datm_forced_restoring if restoring file is available
#--------------------------------------------------------------------
@@ -478,7 +490,8 @@ def buildnml(case, caseroot, compname):
lines.append('')
lines.append('')
lines.append('')
lines.append('')
lines.append(' ')
lines.append(' ')
- if not ocn_grid.startswith("oRRS1"):
+ if not (ocn_grid.startswith("oRRS1") or ocn_grid.startswith("RRSwISC6")):
lines.append(' ')
lines.append(' ')
lines.append(' ')
@@ -1421,7 +1439,8 @@ def buildnml(case, caseroot, compname):
lines.append('240.0
120.0
60.0
+900.0
'noleap'
'2000-01-01_00:00:00'
'none'
@@ -88,6 +89,7 @@
75.0
85.0
85.0
+85.0
-60.0
-75.0
-75.0
@@ -102,6 +104,7 @@
-85.0
-85.0
-85.0
+-85.0
'uniform'
0.0
0.0
@@ -164,6 +167,7 @@
1
1
1
+2
true
true
120
diff --git a/components/mpas-seaice/cime_config/buildnml b/components/mpas-seaice/cime_config/buildnml
index 0aa12105bf9a..d8f7cb8f75b1 100755
--- a/components/mpas-seaice/cime_config/buildnml
+++ b/components/mpas-seaice/cime_config/buildnml
@@ -307,6 +307,15 @@ def buildnml(case, caseroot, compname):
grid_date = '20231121'
grid_prefix = 'mpassi.IcoswISC30E3r5.rstFromG-chrysalis'
+ elif ice_grid == 'RRS6to18E3r6':
+ decomp_date = '20240404'
+ decomp_prefix = 'partitions/mpas-seaice.graph.info.'
+ grid_date = '20240402'
+ grid_prefix = 'mpassi.RRS6to18E3r6'
+ if ice_ic_mode == 'spunup':
+ logger.warning("WARNING: The specified compset is requesting seaice ICs spunup from a G-case")
+ logger.warning(" But no file available for this grid.")
+
elif ice_grid == 'ICOS10':
grid_date = '211015'
grid_prefix = 'seaice.ICOS10'
@@ -440,7 +449,8 @@ def buildnml(case, caseroot, compname):
lines.append('')
lines.append('