!
! $Id $
!
SUBROUTINE criterion_ice_stop_water_slope(cell_area,ini_surf,qsurf,STOPPING,ngrid,initial_h2o_ice)

  USE temps_mod_evol, ONLY: alpha_criterion
	  use comslope_mod, ONLY: subslope_dist,nslope

      IMPLICIT NONE

!=======================================================================
!
!  Routine that checks if the criterion to stop the PEM is reached
!
!=======================================================================

!   arguments:
!   ----------

!   INPUT
  INTEGER, intent(in) :: ngrid                  ! # of grid physical grid points 
  REAL,    intent(in) :: cell_area(ngrid)       ! physical point field : Area of the cells
  REAL,    intent(in) ::  qsurf(ngrid,nslope)          ! physical point field : Actual density of water ice
  REAL,    intent(in) :: ini_surf
  REAL,    intent(in) :: initial_h2o_ice(ngrid,nslope)

!   OUTPUT
  LOGICAL, intent(out) :: STOPPING              ! Logical : is the criterion reached?

!   local:
!   -----
  INTEGER :: i,islope                    ! Loop
  REAL :: present_surf  ! Initial/Actual surface of water ice

!=======================================================================

!   initialisation to false
    STOPPING=.FALSE.

!   computation of the present surface of water ice sublimating
  present_surf=0.
  do i=1,ngrid
    do islope=1, nslope
      if (initial_h2o_ice(i,islope).GT.0.5 .and. qsurf(i,islope).GT.0.) then
         present_surf=present_surf+cell_area(i)*subslope_dist(i,islope)
      endif
    enddo
  enddo
  
!   check of the criterion
  if(present_surf.LT.ini_surf*(1-alpha_criterion) .OR. &
     present_surf.GT.ini_surf*(1+alpha_criterion)) then
    STOPPING=.TRUE. 
    print *, "Reason of stopping : The surface of water ice sublimating reach the threshold:"
    print *, "Current surface of water ice sublimating=", present_surf
    print *, "Initial surface of water ice sublimating=", ini_surf
    print *, "Percentage of change accepted=", alpha_criterion*100
    print *, "present_surf<ini_surf*(1-alpha_criterion)", (present_surf.LT.ini_surf*(1-alpha_criterion))
  endif

  if (ini_surf.LT. 1E-5 .and. ini_surf.GT. -1E-5) then
    STOPPING=.FALSE.
  endif

END SUBROUTINE criterion_ice_stop_water_slope