MODULE dynzdf_exp !!============================================================================== !! *** MODULE dynzdf_exp *** !! Ocean dynamics: vertical component(s) of the momentum mixing trend !!============================================================================== !! History : OPA ! 1990-10 (B. Blanke) Original code !! 8.0 ! 1997-05 (G. Madec) vertical component of isopycnal !! NEMO 0.5 ! 2002-08 (G. Madec) F90: Free form and module !! 3.3 ! 2010-04 (M. Leclair, G. Madec) Forcing averaged over 2 time steps !!---------------------------------------------------------------------- !!---------------------------------------------------------------------- !! dyn_zdf_exp : update the momentum trend with the vertical diffu- !! sion using an explicit time-stepping scheme. !!---------------------------------------------------------------------- USE oce ! ocean dynamics and tracers USE dom_oce ! ocean space and time domain USE phycst ! physical constants USE zdf_oce ! ocean vertical physics USE sbc_oce ! surface boundary condition: ocean USE lib_mpp ! MPP library USE in_out_manager ! I/O manager USE lib_mpp ! MPP library USE wrk_nemo ! Memory Allocation USE timing ! Timing USE yomhook, ONLY: lhook, dr_hook USE parkind1, ONLY: jprb, jpim IMPLICIT NONE PRIVATE PUBLIC dyn_zdf_exp ! called by step.F90 !! * Substitutions # include "domzgr_substitute.h90" # include "vectopt_loop_substitute.h90" !!---------------------------------------------------------------------- !! NEMO/OPA 3.3 , NEMO Consortium (2010) !! $Id$ !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) !!---------------------------------------------------------------------- CONTAINS SUBROUTINE dyn_zdf_exp( kt, p2dt ) !!---------------------------------------------------------------------- !! *** ROUTINE dyn_zdf_exp *** !! !! ** Purpose : Compute the trend due to the vert. momentum diffusion !! !! ** Method : Explicit forward time stepping with a time splitting !! technique. The vertical diffusion of momentum is given by: !! diffu = dz( avmu dz(u) ) = 1/e3u dk+1( avmu/e3uw dk(ub) ) !! Surface boundary conditions: wind stress input (averaged over kt-1/2 & kt+1/2) !! Bottom boundary conditions : bottom stress (cf zdfbfr.F90) !! Add this trend to the general trend ua : !! ua = ua + dz( avmu dz(u) ) !! !! ** Action : - Update (ua,va) with the vertical diffusive trend !!--------------------------------------------------------------------- INTEGER , INTENT(in) :: kt ! ocean time-step index REAL(wp), INTENT(in) :: p2dt ! time-step ! INTEGER :: ji, jj, jk, jl ! dummy loop indices REAL(wp) :: zlavmr, zua, zva ! local scalars REAL(wp), POINTER, DIMENSION(:,:,:) :: zwx, zwy, zwz, zww INTEGER(KIND=jpim), PARAMETER :: zhook_in = 0 INTEGER(KIND=jpim), PARAMETER :: zhook_out = 1 REAL(KIND=jprb) :: zhook_handle CHARACTER(LEN=*), PARAMETER :: RoutineName='DYN_ZDF_EXP' IF (lhook) CALL dr_hook(RoutineName,zhook_in,zhook_handle) !!---------------------------------------------------------------------- ! IF( nn_timing == 1 ) CALL timing_start('dyn_zdf_exp') ! CALL wrk_alloc( jpi,jpj,jpk, zwx, zwy, zwz, zww ) ! IF( kt == nit000 .AND. lwp ) THEN WRITE(numout,*) WRITE(numout,*) 'dyn_zdf_exp : vertical momentum diffusion - explicit operator' WRITE(numout,*) '~~~~~~~~~~~ ' ENDIF zlavmr = 1. / REAL( nn_zdfexp ) DO jj = 2, jpjm1 ! Surface boundary condition DO ji = 2, jpim1 zwy(ji,jj,1) = ( utau_b(ji,jj) + utau(ji,jj) ) * r1_rau0 zww(ji,jj,1) = ( vtau_b(ji,jj) + vtau(ji,jj) ) * r1_rau0 END DO END DO DO jk = 1, jpk ! Initialization of x, z and contingently trends array DO jj = 2, jpjm1 DO ji = 2, jpim1 zwx(ji,jj,jk) = ub(ji,jj,jk) zwz(ji,jj,jk) = vb(ji,jj,jk) END DO END DO END DO ! DO jl = 1, nn_zdfexp ! Time splitting loop ! DO jk = 2, jpk ! First vertical derivative DO jj = 2, jpjm1 DO ji = 2, jpim1 zwy(ji,jj,jk) = avmu(ji,jj,jk) * ( zwx(ji,jj,jk-1) - zwx(ji,jj,jk) ) / fse3uw(ji,jj,jk) zww(ji,jj,jk) = avmv(ji,jj,jk) * ( zwz(ji,jj,jk-1) - zwz(ji,jj,jk) ) / fse3vw(ji,jj,jk) END DO END DO END DO DO jk = 1, jpkm1 ! Second vertical derivative and trend estimation at kt+l*rdt/nn_zdfexp DO jj = 2, jpjm1 DO ji = 2, jpim1 zua = zlavmr * ( zwy(ji,jj,jk) - zwy(ji,jj,jk+1) ) / fse3u(ji,jj,jk) zva = zlavmr * ( zww(ji,jj,jk) - zww(ji,jj,jk+1) ) / fse3v(ji,jj,jk) ua(ji,jj,jk) = ua(ji,jj,jk) + zua va(ji,jj,jk) = va(ji,jj,jk) + zva ! zwx(ji,jj,jk) = zwx(ji,jj,jk) + p2dt * zua * umask(ji,jj,jk) zwz(ji,jj,jk) = zwz(ji,jj,jk) + p2dt * zva * vmask(ji,jj,jk) END DO END DO END DO ! END DO ! End of time splitting ! CALL wrk_dealloc( jpi,jpj,jpk, zwx, zwy, zwz, zww ) ! IF( nn_timing == 1 ) CALL timing_stop('dyn_zdf_exp') ! IF (lhook) CALL dr_hook(RoutineName,zhook_out,zhook_handle) END SUBROUTINE dyn_zdf_exp !!============================================================================== END MODULE dynzdf_exp