diff --git a/components/mpas-ocean/src/Registry.xml b/components/mpas-ocean/src/Registry.xml
index 31c2e8978b1d..a9900cf8467f 100644
--- a/components/mpas-ocean/src/Registry.xml
+++ b/components/mpas-ocean/src/Registry.xml
@@ -3958,18 +3958,18 @@
 		/>
 		<var_array name="avgTracersSurfaceValue" type="real" dimensions="nCells Time" packages="forwardMode;analysisMode">
 			<var name="avgTemperatureSurfaceValue" array_group="surfaceValues" units="C"
-				 description="Time averaged potential temperature extrapolated to ocean surface"
+				 description="Time averaged potential temperature in the uppermost active level as determined by minLevelCell"
 			/>
 			<var name="avgSalinitySurfaceValue" array_group="surfaceValues" units="1.e-3"
-				 description="Time averaged salinity extrapolated to ocean surface"
+				 description="Time averaged salinity in the uppermost active level as determined by minLevelCell"
 			/>
 		</var_array>
 		<var_array name="avgSurfaceVelocity" type="real" dimensions="nCells Time" packages="forwardMode;analysisMode">
 			<var name="avgSurfaceVelocityZonal" array_group="vel_zonal" units="m s^-1"
-				 description="Time averaged zonal surface velocity"
+				 description="Time averaged zonal surface velocity located in minLevelCell"
 			/>
 			<var name="avgSurfaceVelocityMeridional" array_group="vel_meridional" units="m s^-1"
-				 description="Time averaged meridional surface velocity"
+				 description="Time averaged meridional surface velocity located in minLevelCell"
 			/>
 		</var_array>
 		<var_array name="avgSSHGradient" type="real" dimensions="nCells Time" packages="forwardMode;analysisMode">
diff --git a/components/mpas-ocean/src/shared/mpas_ocn_diagnostics.F b/components/mpas-ocean/src/shared/mpas_ocn_diagnostics.F
index 691bfe70b589..e9c0c1e44fde 100644
--- a/components/mpas-ocean/src/shared/mpas_ocn_diagnostics.F
+++ b/components/mpas-ocean/src/shared/mpas_ocn_diagnostics.F
@@ -399,9 +399,9 @@ subroutine ocn_diagnostic_solve(dt, statePool, forcingPool, meshPool, verticalMe
 
       !
       ! extrapolate tracer values to ocean surface
-      ! this eventually be a modelled process
-      ! at present, just copy k=1 tracer values onto surface values
-      ! field will be updated below is better approximations are available
+      ! this eventually could be a modelled process
+      ! at present, just copy minLevelCell tracer values onto surface values
+      ! field will be updated below as better approximations are available
 
 !TDR need to consider how to handle tracersSurfaceValues
 #ifdef MPAS_OPENACC