Make model err if SGH dt < 1 millisecond

Author: matthewhoffman

src/core_landice/mode_forward/mpas_li_subglacial_hydro.F

@@ -327,7 +327,7 @@ subroutine li_SGH_solve(domain, err)
       ! =============
       ! =============
       ! =============
-      do while (timeLeft > 0.0_RKIND)
+      timecycling: do while (timeLeft > 0.0_RKIND)
       numSubCycles = numSubCycles + 1
 
 
@@ -468,6 +468,9 @@ subroutine li_SGH_solve(domain, err)
       ! =============
       call check_timestep(domain, timeLeft, err_tmp)
       err = ior(err, err_tmp)
+      if (err > 0) then
+         exit timecycling
+      endif
 
 
       ! =============
@@ -580,7 +583,7 @@ subroutine li_SGH_solve(domain, err)
       ! =============
       ! =============
       ! =============
-      end do  ! while timeLeft>0
+      end do timecycling ! while timeLeft>0
       ! =============
       ! =============
       ! =============
@@ -1156,6 +1159,10 @@ subroutine check_timestep(domain, timeLeft, err)
          endif
       endif
 
+      if (proposedDt < 1.0E-3_RKIND) then
+         call mpas_log_write("CFL conditions are limiting subglacial hydrology timestep to <1 millisecond.", MPAS_LOG_ERR)
+         err = ior(err, 1)
+      endif
 
       ! Don't exceed the maximum allowed hydro time step
       proposedDt = min(proposedDt, maxDt)
@@ -1201,6 +1208,7 @@ subroutine check_timestep(domain, timeLeft, err)
             realArgs=(/deltatSGH, deltatSGHdiffuChannel/))
       endif
 
+
    !--------------------------------------------------------------------
    end subroutine check_timestep