diff --git a/components/elm/bld/namelist_files/namelist_defaults.xml b/components/elm/bld/namelist_files/namelist_defaults.xml
index 4fe7f81874e4..7c9480979f19 100644
--- a/components/elm/bld/namelist_files/namelist_defaults.xml
+++ b/components/elm/bld/namelist_files/namelist_defaults.xml
@@ -556,6 +556,10 @@ this mask will have smb calculated over the entire global land surface
lnd/clm2/snicardata/snicar_optics_5bnd_mam_c160322.nc
lnd/clm2/snicardata/snicar_drdt_bst_fit_60_c070416.nc
.true.
+1
+.false.
+.false.
+0
2000
diff --git a/components/elm/bld/namelist_files/namelist_definition.xml b/components/elm/bld/namelist_files/namelist_definition.xml
index 872feb7d347b..58a8f12a78f3 100644
--- a/components/elm/bld/namelist_files/namelist_definition.xml
+++ b/components/elm/bld/namelist_files/namelist_definition.xml
@@ -511,7 +511,7 @@ Per tape series history write frequency.
+group="elm_inparm" valid_values="">
+
+snow shape: 1=sphere (original assumption in SNICAR)
+ 2=spheroid; 3=hexagonal plate; 4=koch snowflake
+
+
+
+is_dust_internal_mixing
+
+
+
+is_BC_internal_mixing
+
+
+
+atmospheric types for snicar
+
+