MODULE usrdef_sbc
   !!======================================================================
   !!                       ***  MODULE usrdef_sbc  ***
   !! 
   !!                  ===  AMM7_SURGE configuration  ===
   !!
   !! User defined :   surface forcing of a user configuration
   !!======================================================================
   !! History :  4.0   ! 2016-03  (S. Flavoni, G. Madec)  user defined interface
   !!            4.0   ! 2017-12  (C. O'Neill)  add necessary options for surge work - either no fluxes 
   !!                                           (for tide-only run) or wind and pressure only
   !!----------------------------------------------------------------------

   !!----------------------------------------------------------------------
   !!   usrdef_sbc    : user defined surface bounday conditions in LOCK_EXCHANGE case
   !!----------------------------------------------------------------------
   USE oce             ! ocean dynamics and tracers
   USE dom_oce         ! ocean space and time domain
   USE sbc_oce         ! Surface boundary condition: ocean fields
   USE sbc_ice         ! Surface boundary condition: ocean fields
   USE fldread         ! read input fields
   USE phycst          ! physical constants
   USE lib_fortran     ! Fortran utilities (allows no signed zero when 'key_nosignedzero' defined) 
   !
   USE in_out_manager  ! I/O manager
   USE iom
   USE lbclnk          ! ocean lateral boundary conditions (or mpp link)
   USE lib_mpp         ! distribued memory computing library
   !USE wrk_nemo       ! work arrays
   USE timing         ! Timing
   USE prtctl         ! Print control

   IMPLICIT NONE
   PRIVATE

   PUBLIC   usrdef_sbc_oce    ! routine called in sbcmod module
   PUBLIC   usrdef_sbc_ice_tau  ! routine called by sbcice_lim.F90 for ice dynamics
   PUBLIC   usrdef_sbc_ice_flx  ! routine called by sbcice_lim.F90 for ice thermo
   !                                  !!* Namelist namsbc_usr
   REAL(wp) ::   rn_vfac     ! multiplication factor for ice/ocean velocity in the calculation of wind stress (clem)
   REAL(wp) ::   rn_charn_const 
   LOGICAL  ::   ln_use_sbc  ! Surface fluxes on or not 


   !! * Substitutions
#  include "vectopt_loop_substitute.h90"
   !!----------------------------------------------------------------------
   !! NEMO/OCE 4.0 , NEMO Consortium (2018)
   !! $Id$
   !! Software governed by the CeCILL license (see ./LICENSE)
   !!----------------------------------------------------------------------
CONTAINS

   SUBROUTINE usrdef_sbc_oce( kt )
      !!---------------------------------------------------------------------
      !!                    ***  ROUTINE usrdef_sbc  ***
      !!              
      !! ** Purpose :   provide at each time-step the surface boundary
      !!              condition, i.e. the momentum, heat and freshwater fluxes.
      !!
      !! ** Method  :   all 0 fields, for AMM7_SURGE case
      !!                CAUTION : never mask the surface stress field !
      !!
      !! ** Action  : - if tide-only case - set to ZERO all the ocean surface boundary condition, i.e.   
      !!                   utau, vtau, taum, wndm, qns, qsr, emp, sfx
      !!              - if tide+surge case - read in wind and air pressure      !!
      !!----------------------------------------------------------------------
      INTEGER, INTENT(in) ::   kt   ! ocean time step

      INTEGER  ::   ios      ! Local integer output status for namelist read
      !
      CHARACTER(len=100) ::  cn_dir   !   Root directory for location of flux files
      TYPE(FLD_N) ::   sn_wndi, sn_wndj                        ! informations about the fields to be read

      NAMELIST/namsbc_usr/ ln_use_sbc, cn_dir , rn_vfac,  &
         &                   sn_wndi, sn_wndj, rn_charn_const
      !!---------------------------------------------------------------------
      !
      IF( kt == nit000 ) THEN
         
         
         REWIND( numnam_cfg )              ! Namelist namsbc_usr in configuration namelist
         READ  ( numnam_cfg, namsbc_usr, IOSTAT = ios, ERR = 902 )
902      IF( ios /= 0 ) CALL ctl_nam ( ios , 'namsbc_surge in configuration namelist' )

         IF(lwm) WRITE( numond, namsbc_usr )

         IF(lwp) WRITE(numout,*)' usr_sbc : AMM7_SURGE tide only case: NO surface forcing'
         IF(lwp) WRITE(numout,*)' ~~~~~~~~~~~   utau = vtau = taum = wndm = qns = qsr = emp = sfx = 0'

         utau(:,:) = 0._wp
         vtau(:,:) = 0._wp
         taum(:,:) = 0._wp
         wndm(:,:) = 0._wp
         !
         emp (:,:) = 0._wp
         sfx (:,:) = 0._wp
         qns (:,:) = 0._wp
         qsr (:,:) = 0._wp
         !         
      ENDIF
      !
   END SUBROUTINE usrdef_sbc_oce


   SUBROUTINE usrdef_sbc_ice_tau( kt )
      INTEGER, INTENT(in) ::   kt   ! ocean time step
   END SUBROUTINE usrdef_sbc_ice_tau

   SUBROUTINE usrdef_sbc_ice_flx( kt )
      INTEGER, INTENT(in) ::   kt   ! ocean time step
   END SUBROUTINE usrdef_sbc_ice_flx

   !!======================================================================
END MODULE usrdef_sbc