Update masks before RK loop, but not at start of each advection stage.

Update masks before RK loop, but not at start of each advection stage.

components/mpas-albany-landice/src/mode_forward/mpas_li_advection.F

@@ -376,10 +376,6 @@ subroutine li_advection_thickness_tracers(&
       ! given the old thickness, compute the thickness in each layer
       call li_calculate_layerThickness(meshPool, thickness, layerThickness)
 
-      ! update masks
-      call li_calculate_mask(meshPool, velocityPool, geometryPool, err_tmp)
-      err = ior(err, err_tmp)
-
       ! Save copies of masks because we need to preserve mask
       ! states prior to advection for accurate time integration.
       ! A mask update is necessary to calculate grounding line flux,

components/mpas-albany-landice/src/mode_forward/mpas_li_time_integration_fe_rk.F

@@ -250,8 +250,6 @@ subroutine li_time_integrator_forwardeuler_rungekutta(domain, err)
       err = ior(err, err_tmp)
       call mpas_timer_stop("face melting for grounded ice")
 
-! *** TODO: Should basal melt rate calculation and column physics go inside RK loop? ***
-
 ! === Basal melting for floating ice ===========
       call mpas_timer_start("basal melting for floating ice")
       call li_basal_melt_floating_ice(domain, err_tmp)
@@ -364,7 +362,13 @@ subroutine li_time_integrator_forwardeuler_rungekutta(domain, err)
                              // ' is not supported with config_rk_order = $i', &
                              intArgs=(/config_rk_order/), messageType=MPAS_LOG_ERR)
          return
-      endif 
+      endif
+
+      ! Calculate masks prior to RK loop, but do not update masks within the loop
+      ! to preserve the accuracy of time integration.
+      call li_calculate_mask(meshPool, velocityPool, geometryPool, err_tmp)
+      err = ior(err, err_tmp)
+
 ! *** Start RK loop ***
       do rkStage = 1, nRKstages
          call mpas_log_write('beginning rk stage $i of $i', &