#include "cppdefs.h"

      MODULE sed_surface_mod

#if defined NONLINEAR && defined SEDIMENT
!
!svn $Id$
!==================================================== John C. Warner ===
!  Copyright (c) 2002-2020 The ROMS/TOMS Group      Hernan G. Arango   !
!    Licensed under a MIT/X style license                              !
!    See License_ROMS.txt                                              !
!=======================================================================
!                                                                      !
!  This routine computed sediment surface layer (sediment-water        !
!  interface) properties.                                              !
!                                                                      !
!  References:                                                         !
!                                                                      !
!  Warner, J.C., C.R. Sherwood, R.P. Signell, C.K. Harris, and H.G.    !
!    Arango, 2008:  Development of a three-dimensional,  regional,     !
!    coupled wave, current, and sediment-transport model, Computers    !
!    & Geosciences, 34, 1284-1306.                                     !
!                                                                      !
!=======================================================================
!
      implicit none

      PRIVATE
      PUBLIC  :: sed_surface

      CONTAINS
!
!***********************************************************************
      SUBROUTINE sed_surface (ng, tile)
!***********************************************************************
!
      USE mod_param
      USE mod_ocean
      USE mod_sedbed
      USE mod_stepping
!
!  Imported variable declarations.
!
      integer, intent(in) :: ng, tile
!
!  Local variable declarations.
!
# include "tile.h"
!
# ifdef PROFILE
      CALL wclock_on (ng, iNLM, 16, __LINE__, __FILE__)
# endif
      CALL sed_surface_tile (ng, tile,                                  &
     &                       LBi, UBi, LBj, UBj,                        &
     &                       IminS, ImaxS, JminS, JmaxS,                &
     &                       nstp(ng), nnew(ng),                        &
     &                       SEDBED(ng) % bed_frac,                     &
     &                       SEDBED(ng) % bottom)
# ifdef PROFILE
      CALL wclock_off (ng, iNLM, 16, __LINE__, __FILE__)
# endif
      RETURN
      END SUBROUTINE sed_surface
!
!***********************************************************************
      SUBROUTINE sed_surface_tile (ng, tile,                            &
     &                             LBi, UBi, LBj, UBj,                  &
     &                             IminS, ImaxS, JminS, JmaxS,          &
     &                             nstp, nnew,                          &
     &                             bed_frac, bottom)
!***********************************************************************
!
      USE mod_param
      USE mod_scalars
      USE mod_sediment
!
      USE bc_3d_mod, ONLY : bc_r3d_tile
# ifdef DISTRIBUTE
      USE mp_exchange_mod, ONLY : mp_exchange3d, mp_exchange4d
# endif
!
!  Imported variable declarations.
!
      integer, intent(in) :: ng, tile
      integer, intent(in) :: LBi, UBi, LBj, UBj
      integer, intent(in) :: IminS, ImaxS, JminS, JmaxS
      integer, intent(in) :: nstp, nnew
!
# ifdef ASSUMED_SHAPE
      real(r8), intent(inout) :: bed_frac(LBi:,LBj:,:,:)
      real(r8), intent(inout) :: bottom(LBi:,LBj:,:)
# else
      real(r8), intent(inout) :: bed_frac(LBi:UBi,LBj:UBj,Nbed,NST)
      real(r8), intent(inout) :: bottom(LBi:UBi,LBj:UBj,MBOTP)
# endif
!
!  Local variable declarations.
!
      integer :: i, ised, j

      real(r8) :: cff1, cff2, cff3, cff4
      real(r8), parameter :: eps = 1.0E-14_r8

# include "set_bounds.h"

!
!  Update mean surface properties.
!  Sd50 must be positive definite, due to BBL routines.
!  Srho must be >1000, due to (s-1) in BBL routines
!
      J_LOOP : DO j=Jstr,Jend
        DO i=Istr,Iend
          cff1=1.0_r8
          cff2=1.0_r8
          cff3=1.0_r8
          cff4=1.0_r8
          DO ised=1,NST
            cff1=cff1*tau_ce(ised,ng)**bed_frac(i,j,1,ised)
            cff2=cff2*Sd50(ised,ng)**bed_frac(i,j,1,ised)
            cff3=cff3*(wsed(ised,ng)+eps)**bed_frac(i,j,1,ised)
            cff4=cff4*Srho(ised,ng)**bed_frac(i,j,1,ised)
          END DO
          bottom(i,j,itauc)=cff1
          bottom(i,j,isd50)=MIN(cff2,Zob(ng))
          bottom(i,j,iwsed)=cff3
          bottom(i,j,idens)=MAX(cff4,1050.0_r8)
        END DO
      END DO J_LOOP
!!
!!  Move bottom roughness computations from BBL routines to here.
!!

!
!-----------------------------------------------------------------------
!  Apply periodic or gradient boundary conditions to property arrays.
!-----------------------------------------------------------------------
!
      CALL bc_r3d_tile (ng, tile,                                       &
     &                  LBi, UBi, LBj, UBj, 1, MBOTP,                   &
     &                  bottom)
# ifdef DISTRIBUTE
      CALL mp_exchange3d (ng, tile, iNLM, 1,                            &
     &                    LBi, UBi, LBj, UBj, 1, MBOTP,                 &
     &                    NghostPoints,                                 &
     &                    EWperiodic(ng), NSperiodic(ng),               &
     &                    bottom)
# endif

      RETURN
      END SUBROUTINE sed_surface_tile
#endif
      END MODULE sed_surface_mod
