MODULE step !!====================================================================== !! *** MODULE step *** !! Time-stepping : manager of the ocean, tracer and ice time stepping !!====================================================================== !!---------------------------------------------------------------------- !! stp : OPA system time-stepping !!---------------------------------------------------------------------- !! * Modules used USE oce ! ocean dynamics and tracers variables USE dom_oce ! ocean space and time domain variables USE zdf_oce ! ocean vertical physics variables USE ldftra_oce USE ldfdyn_oce USE cpl_oce ! coupled ocean-atmosphere variables USE in_out_manager ! I/O manager USE lbclnk USE daymod ! calendar (day routine) USE dtatem ! ocean temperature data (dta_tem routine) USE dtasal ! ocean salinity data (dta_sal routine) USE dtasst ! ocean sea surface temperature (dta_sst routine) USE taumod ! surface stress (tau routine) USE flxmod ! thermohaline fluxes (flx routine) USE ocesbc ! thermohaline fluxes (oce_sbc routine) USE flxrnf ! runoffs (flx_rnf routine) USE flxfwb ! freshwater budget correction (flx_fwb routine) USE closea ! closed sea freshwater budget (flx_clo routine) USE ocfzpt ! surface ocean freezing point (oc_fz_pt routine) USE trcstp ! passive tracer time-stepping (trc_stp routine) USE dynhpg ! hydrostatic pressure grad. (dyn_hpg routine) USE dynhpg_atsk ! hydrostatic pressure grad. (dyn_hpg_atsk routine) USE dynspg_oce ! surface pressure gradient (dyn_spg routine) USE dynspg ! surface pressure gradient (dyn_spg routine) USE dynkeg ! kinetic energy gradient (dyn_keg routine) USE dynvor ! vorticity term (dyn_vor_... routines) USE dynzad ! vertical advection (dyn_adv routine) USE dynldf_bilapg ! lateral mixing (dyn_ldf_bilapg routine) USE dynldf_bilap ! lateral mixing (dyn_ldf_bilap routine) USE dynldf_iso ! lateral mixing (dyn_ldf_iso routine) USE dynldf_lap ! lateral mixing (dyn_ldf_lap routine) USE dynzdf_imp ! vertical diffusion: implicit (dyn_zdf routine) USE dynzdf_imp_atsk ! vertical diffusion: implicit (dyn_zdf routine) USE dynzdf_iso ! vertical diffusion: isopycnal (dyn_zdf routine) USE dynzdf_exp ! vertical diffusion: explicit (dyn_zdf_exp routine) USE dynnxt ! time-stepping (dyn_nxt routine) USE trabbc ! bottom boundary condition (tra_bbc routine) USE trabbl ! bottom boundary layer (tra_bbl routine) USE tradmp ! internal damping (tra_dmp routine) USE traldf_bilapg ! lateral mixing (tra_ldf_bilapg routine) USE traldf_bilap ! lateral mixing (tra_ldf_bilap routine) USE traldf_iso ! lateral mixing (tra_ldf_iso routine) USE traldf_iso_zps ! lateral mixing (tra_ldf_iso_zps routine) USE traldf_lap ! lateral mixing (tra_ldf_lap routine) USE traqsr ! solar radiation penetration (tra_qsr routine) USE tranpc ! non-penetrative convection (tra_npc routine) USE tranxt ! time-stepping (tra_nxt routine) USE traadv_ctl ! advection scheme control (tra_adv_ctl routine) USE traadv_cen2 ! 2nd order centered scheme (tra_adv_cen2 routine) USE traadv_tvd ! TVD scheme (tra_adv_tvd routine) USE traadv_muscl ! MUSCL scheme (tra_adv_muscl routine) USE traadv_muscl2 ! MUSCL2 scheme (tra_adv_muscl2 routine) USE cla ! cross land advection (tra_cla routine) USE trazdf_exp ! vertical diffusion: explicit (tra_zdf_exp routine) USE trazdf_imp ! vertical diffusion: implicit (tra_zdf_imp routine) USE trazdf_iso ! vertical diffusion (tra_zdf_exp routine) USE trazdf_iso_vopt ! vertical diffusion (tra_zdf_exp routine) USE trasbc ! surface boundary condition (tra_sbc routine) USE eosbn2 ! equation of state (eos_bn2 routine) USE obc_par ! open boundary condition variables USE obcdta ! open boundary condition data (obc_dta routine) USE obcrst ! open boundary cond. restart (obc_rst routine) USE obcrad ! open boundary cond. radiation (obc_rad routine) USE obcspg ! open boundary cond spg (obc_spg routine) USE divcur ! hor. divergence and curl (div & cur routines) USE cla_div ! cross land: hor. divergence (div_cla routine) USE wzvmod ! vertical velocity (wzv routine) USE ldfslp ! iso-neutral slopes (ldf_slp routine) USE ldfeiv ! eddy induced velocity coef. (ldf_eiv routine) USE zdfbfr ! bottom friction (zdf_bfr routine) USE zdftke ! TKE vertical mixing (zdf_tke routine) USE zdfkpp ! KPP vertical mixing (zdf_kpp routine) USE zdfddm ! double diffusion mixing (zdf_ddm routine) USE zdfevd ! enhanced vertical diffusion (zdf_evd routine) USE zdfric ! Richardson vertical mixing (zdf_ric routine) USE zdfmxl ! Mixed-layer depth (zdf_mxl routine) USE zpshde ! partial step: hor. derivative (zps_hde routine) USE ice_oce ! sea-ice variable USE icestp ! sea-ice time-stepping (ice_stp routine) USE diawri ! Standard run outputs (dia_wri routine) USE trdicp ! Ocean momentum/tracers trends (trd_wri routine) USE trdmld ! mixed-layer trends (trd_mld routine) USE trdvor ! vorticity budget (trd_vor routine) USE diagap ! hor. mean model-data gap (dia_gap routine) USE diahdy ! dynamic height (dia_hdy routine) USE diaptr ! poleward transports (dia_ptr routine) USE diahth ! thermocline depth (dia_hth routine) USE diafwb ! freshwater budget (dia_fwb routine) USE diaspr ! suface pressure (rigid-lid) (dia_spr routine) USE flo_oce ! floats variables USE floats ! floats computation (flo_stp routine) USE stpctl ! time stepping control (stp_ctl routine) USE restart ! ocean restart (rst_wri routine) USE cpl ! exchanges in coupled mode (cpl_stp routine) USE prtctl ! Print control (prt_ctl routine) #if defined key_agrif USE agrif_opa_sponge ! Momemtum and tracers sponges #endif IMPLICIT NONE PRIVATE !! * Routine accessibility PUBLIC stp ! called by opa.F90 !! * Substitutions # include "domzgr_substitute.h90" # include "zdfddm_substitute.h90" !!---------------------------------------------------------------------- !! OPA 9.0 , LOCEAN-IPSL (2005) !! $Header$ !! This software is governed by the CeCILL licence see modipsl/doc/NEMO_CeCILL.txt !!---------------------------------------------------------------------- CONTAINS SUBROUTINE stp( & #if !defined key_agrif kstp & #endif ) !!---------------------------------------------------------------------- !! *** ROUTINE stp *** !! !! ** Purpose : - Time stepping of OPA (momentum and active tracer eqs.) !! - Time stepping of LIM (dynamic and thermodynamic eqs.) !! - Tme stepping of TRC (passive tracer eqs.) !! !! ** Method : -1- Update forcings and data !! -2- Update ocean physics !! -3- Compute the t and s trends !! -4- Update t and s !! -5- Compute the momentum trends !! -6- Update the horizontal velocity !! -7- Compute the diagnostics variables (rd,N2, div,cur,w) !! -8- Outputs and diagnostics !! !! History : !! ! 91-03 () Original code !! ! 91-11 (G. Madec) !! ! 92-06 (M. Imbard) add a first output record !! ! 96-04 (G. Madec) introduction of dynspg !! ! 96-04 (M.A. Foujols) introduction of passive tracer !! 8.0 ! 97-06 (G. Madec) new architecture of call !! 8.2 ! 97-06 (G. Madec, M. Imbard, G. Roullet) free surface !! 8.2 ! 99-02 (G. Madec, N. Grima) hpg implicit !! 8.2 ! 00-07 (J-M Molines, M. Imbard) Open Bondary Conditions !! 9.0 ! 02-06 (G. Madec) free form, suppress macro-tasking !! " ! 04-08 (C. Talandier) New trends organization !! " ! 05-01 (C. Ethe) Add the KPP closure scheme !!---------------------------------------------------------------------- !! * Arguments INTEGER & #if !defined key_agrif , INTENT( in ) & #endif :: kstp ! ocean time-step index !! * local declarations INTEGER :: indic ! error indicator if < 0 !! --------------------------------------------------------------------- #if defined key_agrif kstp = nit000 + Agrif_Nb_Step() IF ( Agrif_Root() .and. lwp) Write(*,*) '---' IF (lwp) Write(*,*) 'Grid N°',Agrif_Fixed(),' time step ',kstp #endif indic = 1 ! reset to no error condition adatrj = adatrj + rdt/86400._wp CALL day( kstp ) ! Calendar !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ! Update data, open boundaries and Forcings !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< IF( lk_dtatem ) CALL dta_tem( kstp ) ! update 3D temperature data IF( lk_dtasal ) CALL dta_sal( kstp ) ! Salinity data IF( lk_dtasst ) CALL dta_sst( kstp ) ! Sea Surface Temperature data IF( lk_obc ) CALL obc_dta( kstp ) ! update dynamic and tracer data at open boundaries IF( lk_obc ) CALL obc_rad( kstp ) ! compute phase velocities at open boundaries CALL tau( kstp ) ! wind stress CALL flx_rnf( kstp ) ! runoff data CALL flx( kstp ) ! heat and freshwater fluxes IF( lk_ice_lim ) CALL ice_stp( kstp ) ! sea-ice model (Update stress & fluxes) CALL oce_sbc( kstp ) ! ocean surface boudaries IF( ln_fwb ) CALL flx_fwb( kstp ) ! freshwater budget IF( nclosea == 1 ) CALL flx_clo( kstp ) ! closed sea in the domain (update freshwater fluxes) IF( kstp == nit000 ) THEN IF( ninist == 1 ) THEN ! Output the initial state and forcings CALL dia_wri_state( 'output.init' ) ENDIF ENDIF IF(ln_ctl) THEN ! print mean trends (used for debugging) CALL prt_ctl(tab2d_1=emp , clinfo1=' emp - : ', mask1=tmask, ovlap=1) CALL prt_ctl(tab2d_1=emps , clinfo1=' emps - : ', mask1=tmask, ovlap=1) CALL prt_ctl(tab2d_1=qt , clinfo1=' qt - : ', mask1=tmask, ovlap=1) CALL prt_ctl(tab2d_1=qsr , clinfo1=' qsr - : ', mask1=tmask, ovlap=1) CALL prt_ctl(tab2d_1=runoff , clinfo1=' runoff : ', mask1=tmask, ovlap=1) CALL prt_ctl(tab3d_1=tmask , clinfo1=' tmask : ', mask1=tmask, ovlap=1, kdim=jpk) CALL prt_ctl(tab3d_1=tn , clinfo1=' sst - : ', mask1=tmask, ovlap=1, kdim=1) CALL prt_ctl(tab3d_1=sn , clinfo1=' sss - : ', mask1=tmask, ovlap=1, kdim=1) CALL prt_ctl(tab2d_1=taux , clinfo1=' tau - x : ', tab2d_2=tauy, clinfo2=' - y : ', ovlap=1) ENDIF !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ! Ocean physics update !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< !----------------------------------------------------------------------- ! VERTICAL PHYSICS !----------------------------------------------------------------------- ! N.B. ua, va, ta, sa arrays are used as workspace in this section !----------------------------------------------------------------------- CALL bn2( tb, sb, rn2 ) ! before Brunt-Vaisala frequency ! ! Vertical eddy viscosity and diffusivity coefficients IF( lk_zdfric ) CALL zdf_ric( kstp ) ! Richardson number dependent Kz IF( lk_zdftke ) CALL zdf_tke( kstp ) ! TKE closure scheme for Kz IF( lk_zdfkpp ) CALL zdf_kpp( kstp ) ! KPP closure scheme for Kz IF( lk_zdfcst ) avt (:,:,:) = avt0 * tmask(:,:,:) ! Constant Kz (reset avt to the background value) IF( cp_cfg == "orca" ) THEN ! ORCA: Reduce vertical mixing in some specific areas SELECT CASE ( jp_cfg ) CASE ( 05 ) ! ORCA R2 configuration avt (:,:,2) = avt (:,:,2) + 1.e-3 * upsrnfh(:,:) ! increase diffusivity of rivers mouths END SELECT ENDIF IF( ln_zdfevd ) CALL zdf_evd( kstp ) ! enhanced vertical eddy diffusivity IF( lk_zdfddm .AND. .NOT. lk_zdfkpp) & & CALL zdf_ddm( kstp ) ! double diffusive mixing CALL zdf_bfr( kstp ) ! bottom friction CALL zdf_mxl( kstp ) ! mixed layer depth !----------------------------------------------------------------------- ! LATERAL PHYSICS !----------------------------------------------------------------------- ! N.B. ua, va, ta, sa arrays are used as workspace in this section !----------------------------------------------------------------------- IF( lk_ldfslp ) CALL ldf_slp( kstp, rhd, rn2 ) ! before slope of the lateral mixing #if defined key_traldf_c2d IF( lk_traldf_eiv ) CALL ldf_eiv( kstp ) ! eddy induced velocity coefficient #endif #if defined key_passivetrc !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ! Passive Tracer Model !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< ! N.B. ua, va, ta, sa arrays are used as workspace in this section !----------------------------------------------------------------------- CALL trc_stp( kstp, indic ) ! time-stepping #endif !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ! Active tracers !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< ! N.B. ua, va arrays are used as workspace in this section !----------------------------------------------------------------------- ta(:,:,:) = 0.e0 ! set tracer trends to zero sa(:,:,:) = 0.e0 CALL tra_sbc( kstp ) ! surface boundary condition IF( ln_traqsr ) CALL tra_qsr( kstp ) ! penetrative solar radiation qsr IF( lk_trabbc ) CALL tra_bbc( kstp ) ! bottom heat flux IF( lk_trabbl_dif ) CALL tra_bbl_dif( kstp ) ! diffusive bottom boundary layer scheme IF( lk_trabbl_adv ) CALL tra_bbl_adv( kstp ) ! advective (and/or diffusive) bottom boundary layer scheme IF( lk_tradmp ) CALL tra_dmp( kstp ) ! internal damping trends ! ! horizontal & vertical advection IF( kstp == nit000 ) CALL tra_adv_ctl ! chose/control the scheme used IF( ln_traadv_cen2 ) CALL tra_adv_cen2 ( kstp ) ! 2nd order centered scheme IF( ln_traadv_tvd ) CALL tra_adv_tvd ( kstp ) ! TVD scheme IF( ln_traadv_muscl ) CALL tra_adv_muscl ( kstp ) ! MUSCL scheme IF( ln_traadv_muscl2 ) CALL tra_adv_muscl2( kstp ) ! MUSCL2 scheme IF( n_cla == 1 ) CALL tra_cla( kstp ) ! Cross Land Advection (Update Hor. advection) ! ! lateral mixing IF( l_traldf_lap ) CALL tra_ldf_lap ( kstp ) ! iso-level laplacian IF( l_traldf_bilap ) CALL tra_ldf_bilap ( kstp ) ! iso-level bilaplacian IF( l_traldf_bilapg ) CALL tra_ldf_bilapg ( kstp ) ! s-coord. horizontal bilaplacian IF( l_traldf_iso ) CALL tra_ldf_iso ( kstp ) ! iso-neutral/geopot. laplacian IF( l_traldf_iso_zps ) CALL tra_ldf_iso_zps( kstp ) ! partial step iso-neutral/geopot. laplacian #if defined key_agrif IF (.NOT. Agrif_Root()) CALL Agrif_Sponge_tra( kstp ) ! tracers sponge #endif ! ! vertical diffusion IF( l_trazdf_exp ) CALL tra_zdf_exp ( kstp ) ! explicit time stepping (time splitting scheme) IF( l_trazdf_imp ) CALL tra_zdf_imp ( kstp ) ! implicit time stepping (euler backward) IF( l_trazdf_iso ) CALL tra_zdf_iso ( kstp ) ! isopycnal IF( l_trazdf_iso_vo ) CALL tra_zdf_iso_vopt( kstp ) ! vector opt. isopycnal CALL tra_nxt( kstp ) ! tracer fields at next time step IF( ln_zdfnpc ) CALL tra_npc( kstp ) ! update the new (t,s) fields by non ! ! penetrative convective adjustment IF( ln_dynhpg_imp ) THEN ! semi-implicit hpg CALL eos( ta, sa, rhd, rhop ) ! Time-filtered in situ density used in dynhpg module IF( lk_zps ) CALL zps_hde( kstp, ta, sa, rhd, & ! Partial steps: time filtered hor. gradient & gtu, gsu, gru, & ! of t, s, rd at the bottom ocean level & gtv, gsv, grv ) ELSE ! centered hpg (default case) CALL eos( tb, sb, rhd, rhop ) ! now (swap=before) in situ density for dynhpg module IF( lk_zps ) CALL zps_hde( kstp, tb, sb, rhd, & ! Partial steps: now horizontal gradient & gtu, gsu, gru, & ! of t, s, rd at the bottom ocean level & gtv, gsv, grv ) ENDIF !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ! Dynamics !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< ! N.B. ta, sa arrays are used as workspace in this section !----------------------------------------------------------------------- ua(:,:,:) = 0.e0 ! set dynamics trends to zero va(:,:,:) = 0.e0 CALL dyn_keg( kstp ) ! horizontal gradient of kinetic energy ! ! vorticity term including Coriolis IF( kstp == nit000 ) CALL dyn_vor_ctl ! chose/control the scheme used IF( ln_dynvor_ens ) CALL dyn_vor_enstrophy( kstp ) ! enstrophy conserving scheme IF( ln_dynvor_ene ) CALL dyn_vor_energy ( kstp ) ! energy conserving scheme IF( ln_dynvor_mix ) CALL dyn_vor_mixed ( kstp ) ! mixed energy/enstrophy conserving scheme IF( ln_dynvor_een ) CALL dyn_vor_ene_ens ( kstp ) ! combined energy/enstrophy conserving scheme ! ! lateral mixing IF( l_dynldf_lap ) CALL dyn_ldf_lap ( kstp ) ! iso-level laplacian IF( l_dynldf_bilap ) CALL dyn_ldf_bilap ( kstp ) ! iso-level bilaplacian IF( l_dynldf_bilapg ) CALL dyn_ldf_bilapg ( kstp ) ! s-coord. horizontal bilaplacian IF( l_dynldf_iso ) CALL dyn_ldf_iso ( kstp ) ! iso-neutral laplacian #if defined key_agrif IF (.NOT. Agrif_Root()) CALL Agrif_Sponge_dyn( kstp ) ! momemtum sponge #endif ! ! horizontal gradient of Hydrostatic pressure IF ( lk_jki ) THEN CALL dyn_hpg_atsk( kstp ) ! autotask case (j-k-i loop) ELSE CALL dyn_hpg ( kstp ) ! default case (k-j-i loop) ENDIF CALL dyn_zad ( kstp ) ! vertical advection ! ! vertical diffusion IF( l_dynzdf_exp ) CALL dyn_zdf_exp ( kstp ) ! explicit time stepping (time splitting scheme) IF( l_dynzdf_imp ) CALL dyn_zdf_imp ( kstp ) ! implicit time stepping (euler backward) IF( l_dynzdf_imp_tsk ) CALL dyn_zdf_imp_tsk( kstp ) ! autotask implicit time stepping (euler backward) IF( l_dynzdf_iso ) CALL dyn_zdf_iso ( kstp ) ! iso-neutral case IF( lk_dynspg_rl ) THEN IF( lk_obc ) CALL obc_spg( kstp ) ! surface pressure gradient at open boundaries ENDIF indic=0 !i bug lbc sur emp CALL lbc_lnk( emp, 'T', 1. ) !i CALL dyn_spg( kstp, indic ) ! surface pressure gradient CALL dyn_nxt( kstp ) ! velocity at next time step !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ! Computation of diagnostic variables !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< ! N.B. ua, va, ta, sa arrays are used as workspace in this section !----------------------------------------------------------------------- CALL oc_fz_pt ! ocean surface freezing temperature CALL div_cur( kstp ) ! Horizontal divergence & Relative vorticity IF( n_cla == 1 ) CALL div_cla( kstp ) ! Cross Land Advection (Update Hor. divergence) CALL wzv( kstp ) ! Vertical velocity !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ! Control, diagnostics and outputs !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< ! N.B. ua, va, ta, sa arrays are used as workspace in this section !----------------------------------------------------------------------- ! ! Time loop: control and print CALL stp_ctl( kstp, indic ) IF ( indic < 0 ) nstop = nstop + 1 IF ( nstop == 0 ) THEN ! ! Diagnostics: IF( lk_floats ) CALL flo_stp( kstp ) ! drifting Floats IF( lk_trddyn ) CALL trd_dwr( kstp ) ! trends: dynamics IF( lk_trdtra ) CALL trd_twr( kstp ) ! trends: active tracers IF( lk_trdmld ) CALL trd_mld( kstp ) ! trends: Mixed-layer IF( lk_trdvor ) CALL trd_vor( kstp ) ! trends: vorticity budget IF( lk_diaspr ) CALL dia_spr( kstp ) ! Surface pressure diagnostics IF( lk_diahth ) CALL dia_hth( kstp ) ! Thermocline depth (20 degres isotherm depth) IF( lk_diagap ) CALL dia_gap( kstp ) ! basin averaged diagnostics IF( lk_diahdy ) CALL dia_hdy( kstp ) ! dynamical heigh diagnostics IF( lk_diafwb ) CALL dia_fwb( kstp ) ! Fresh water budget diagnostics IF( ln_diaptr .AND. ( kstp == nit000 .OR. MOD( kstp, nf_ptr ) == 0 ) ) & CALL dia_ptr( kstp ) ! Poleward TRansports diagnostics ! ! save and outputs CALL rst_write ( kstp ) ! ocean model: restart file output IF( lk_obc ) CALL obc_rst_wri( kstp ) ! ocean model: open boundary restart file output CALL dia_wri ( kstp, indic ) ! ocean model: outputs ENDIF !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ! Coupled mode !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< IF( lk_cpl ) CALL cpl_stp( kstp ) ! coupled mode : field exchanges END SUBROUTINE stp !!====================================================================== END MODULE step