MODULE limsbc !!====================================================================== !! *** MODULE limsbc *** !! computation of the flux at the sea ice/ocean interface !!====================================================================== !! History : - ! 2006-07 (M. Vancoppelle) LIM3 original code !! 3.0 ! 2008-03 (C. Tallandier) surface module !! - ! 2008-04 (C. Tallandier) split in 2 + new ice-ocean coupling !! 3.3 ! 2010-05 (G. Madec) decrease ocean & ice reference salinities in the Baltic sea !! ! + simplification of the ice-ocean stress calculation !! 3.4 ! 2011-02 (G. Madec) dynamical allocation !! - ! 2012 (D. Iovino) salt flux change !! - ! 2012-05 (C. Rousset) add penetration solar flux !! 3.5 ! 2012-10 (A. Coward, G. Madec) salt fluxes ; ice+snow mass !!---------------------------------------------------------------------- #if defined key_lim3 !!---------------------------------------------------------------------- !! 'key_lim3' LIM 3.0 sea-ice model !!---------------------------------------------------------------------- !! lim_sbc_alloc : allocate the limsbc arrays !! lim_sbc_init : initialisation !! lim_sbc_flx : updates mass, heat and salt fluxes at the ocean surface !! lim_sbc_tau : update i- and j-stresses, and its modulus at the ocean surface !!---------------------------------------------------------------------- USE par_oce ! ocean parameters USE phycst ! physical constants USE dom_oce ! ocean domain USE ice ! LIM sea-ice variables USE sbc_ice ! Surface boundary condition: sea-ice fields USE sbc_oce ! Surface boundary condition: ocean fields USE sbccpl USE oce , ONLY : sshn, sshb, snwice_mass, snwice_mass_b, snwice_fmass USE albedo ! albedo parameters USE lbclnk ! ocean lateral boundary condition - MPP exchanges USE lib_mpp ! MPP library USE wrk_nemo ! work arrays USE in_out_manager ! I/O manager USE prtctl ! Print control USE lib_fortran ! Fortran utilities (allows no signed zero when 'key_nosignedzero' defined) USE traqsr ! add penetration of solar flux in the calculation of heat budget USE iom USE domvvl ! Variable volume USE limctl USE limcons IMPLICIT NONE PRIVATE PUBLIC lim_sbc_init ! called by sbc_lim_init PUBLIC lim_sbc_flx ! called by sbc_ice_lim PUBLIC lim_sbc_tau ! called by sbc_ice_lim REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:) :: utau_oce, vtau_oce ! air-ocean surface i- & j-stress [N/m2] REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:) :: tmod_io ! modulus of the ice-ocean velocity [m/s] REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:) :: soce_0 , sice_0 ! cst SSS and ice salinity (levitating sea-ice) !! * Substitutions # include "vectopt_loop_substitute.h90" # include "domzgr_substitute.h90" !!---------------------------------------------------------------------- !! NEMO/LIM3 4.0 , UCL - NEMO Consortium (2011) !! $Id: limsbc.F90 4990 2014-12-15 16:42:49Z timgraham $ !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) !!---------------------------------------------------------------------- CONTAINS INTEGER FUNCTION lim_sbc_alloc() !!------------------------------------------------------------------- !! *** ROUTINE lim_sbc_alloc *** !!------------------------------------------------------------------- ALLOCATE( soce_0(jpi,jpj) , utau_oce(jpi,jpj) , & & sice_0(jpi,jpj) , vtau_oce(jpi,jpj) , tmod_io(jpi,jpj), STAT=lim_sbc_alloc) ! IF( lk_mpp ) CALL mpp_sum( lim_sbc_alloc ) IF( lim_sbc_alloc /= 0 ) CALL ctl_warn('lim_sbc_alloc: failed to allocate arrays') END FUNCTION lim_sbc_alloc SUBROUTINE lim_sbc_flx( kt ) !!------------------------------------------------------------------- !! *** ROUTINE lim_sbc_flx *** !! !! ** Purpose : Update the surface ocean boundary condition for heat !! salt and mass over areas where sea-ice is non-zero !! !! ** Action : - computes the heat and freshwater/salt fluxes !! at the ice-ocean interface. !! - Update the ocean sbc !! !! ** Outputs : - qsr : sea heat flux: solar !! - qns : sea heat flux: non solar !! - emp : freshwater budget: volume flux !! - sfx : salt flux !! - fr_i : ice fraction !! - tn_ice : sea-ice surface temperature !! - alb_ice : sea-ice albedo (recomputed only for coupled mode) !! !! References : Goosse, H. et al. 1996, Bul. Soc. Roy. Sc. Liege, 65, 87-90. !! Tartinville et al. 2001 Ocean Modelling, 3, 95-108. !! These refs are now obsolete since everything has been revised !! The ref should be Rousset et al., 2015 !!--------------------------------------------------------------------- INTEGER, INTENT(in) :: kt ! number of iteration INTEGER :: ji, jj, jl, jk ! dummy loop indices REAL(wp) :: zqmass ! Heat flux associated with mass exchange ice->ocean (W.m-2) REAL(wp) :: zqsr ! New solar flux received by the ocean ! REAL(wp), POINTER, DIMENSION(:,:,:) :: zalb_cs, zalb_os ! 3D workspace REAL(wp), POINTER, DIMENSION(:,:) :: zalb ! 2D workspace !!--------------------------------------------------------------------- ! make call for albedo output before it is modified CALL wrk_alloc( jpi,jpj, zalb ) zalb(:,:) = 0._wp WHERE ( SUM( a_i_b, dim=3 ) <= epsi06 ) ; zalb(:,:) = 0.066_wp ELSEWHERE ; zalb(:,:) = SUM( alb_ice * a_i_b, dim=3 ) / SUM( a_i_b, dim=3 ) END WHERE IF( iom_use('alb_ice' ) ) CALL iom_put( "alb_ice" , zalb(:,:) ) ! ice albedo output zalb(:,:) = SUM( alb_ice * a_i_b, dim=3 ) + 0.066_wp * ( 1._wp - SUM( a_i_b, dim=3 ) ) IF( iom_use('albedo' ) ) CALL iom_put( "albedo" , zalb(:,:) ) ! ice albedo output CALL wrk_dealloc( jpi,jpj, zalb ) ! DO jj = 1, jpj DO ji = 1, jpi !------------------------------------------! ! heat flux at the ocean surface ! !------------------------------------------! ! Solar heat flux reaching the ocean = zqsr (W.m-2) !--------------------------------------------------- zqsr = qsr_tot(ji,jj) DO jl = 1, jpl zqsr = zqsr - a_i_b(ji,jj,jl) * ( qsr_ice(ji,jj,jl) - ftr_ice(ji,jj,jl) ) END DO ! Total heat flux reaching the ocean = hfx_out (W.m-2) !--------------------------------------------------- zqmass = hfx_thd(ji,jj) + hfx_dyn(ji,jj) + hfx_res(ji,jj) ! heat flux from snow is 0 (T=0 degC) hfx_out(ji,jj) = hfx_out(ji,jj) + zqmass + zqsr ! Add the residual from heat diffusion equation and sublimation (W.m-2) !---------------------------------------------------------------------- hfx_out(ji,jj) = hfx_out(ji,jj) + hfx_err_dif(ji,jj) + & & ( hfx_sub(ji,jj) - SUM( qevap_ice(ji,jj,:) * a_i_b(ji,jj,:) ) ) ! New qsr and qns used to compute the oceanic heat flux at the next time step !---------------------------------------------------------------------------- qsr(ji,jj) = zqsr qns(ji,jj) = hfx_out(ji,jj) - zqsr !------------------------------------------! ! mass flux at the ocean surface ! !------------------------------------------! ! case of realistic freshwater flux (Tartinville et al., 2001) (presently ACTIVATED) ! ------------------------------------------------------------------------------------- ! The idea of this approach is that the system that we consider is the ICE-OCEAN system ! Thus FW flux = External ( E-P+snow melt) ! Salt flux = Exchanges in the ice-ocean system then converted into FW ! Associated to Ice formation AND Ice melting ! Even if i see Ice melting as a FW and SALT flux ! ! mass flux from ice/ocean wfx_ice(ji,jj) = wfx_bog(ji,jj) + wfx_bom(ji,jj) + wfx_sum(ji,jj) + wfx_sni(ji,jj) & + wfx_opw(ji,jj) + wfx_dyn(ji,jj) + wfx_res(ji,jj) ! mass flux at the ocean/ice interface fmmflx(ji,jj) = - ( wfx_ice(ji,jj) + wfx_snw(ji,jj) + wfx_err_sub(ji,jj) ) ! F/M mass flux save at least for biogeochemical model emp(ji,jj) = emp_oce(ji,jj) - wfx_ice(ji,jj) - wfx_snw(ji,jj) - wfx_err_sub(ji,jj) ! mass flux + F/M mass flux (always ice/ocean mass exchange) END DO END DO !------------------------------------------! ! salt flux at the ocean surface ! !------------------------------------------! sfx(:,:) = sfx_bog(:,:) + sfx_bom(:,:) + sfx_sum(:,:) + sfx_sni(:,:) + sfx_opw(:,:) & & + sfx_res(:,:) + sfx_dyn(:,:) + sfx_bri(:,:) + sfx_sub(:,:) !-------------------------------------------------------------! ! mass of snow and ice per unit area for embedded sea-ice ! !-------------------------------------------------------------! IF( nn_ice_embd /= 0 ) THEN ! save mass from the previous ice time step snwice_mass_b(:,:) = snwice_mass(:,:) ! new mass per unit area snwice_mass (:,:) = tmask(:,:,1) * ( rhosn * vt_s(:,:) + rhoic * vt_i(:,:) ) ! time evolution of snow+ice mass snwice_fmass (:,:) = ( snwice_mass(:,:) - snwice_mass_b(:,:) ) * r1_rdtice ENDIF !-----------------------------------------------! ! Storing the transmitted variables ! !-----------------------------------------------! fr_i (:,:) = at_i(:,:) ! Sea-ice fraction tn_ice(:,:,:) = t_su(:,:,:) ! Ice surface temperature !------------------------------------------------------------------------! ! Snow/ice albedo (only if sent to coupler, useless in forced mode) ! !------------------------------------------------------------------------! CALL wrk_alloc( jpi, jpj, jpl, zalb_cs, zalb_os ) CALL albedo_ice( t_su, ht_i, ht_s, zalb_cs, zalb_os ) ! cloud-sky and overcast-sky ice albedos alb_ice(:,:,:) = ( 1. - cldf_ice ) * zalb_cs(:,:,:) + cldf_ice * zalb_os(:,:,:) CALL wrk_dealloc( jpi, jpj, jpl, zalb_cs, zalb_os ) ! conservation test IF( ln_limdiahsb ) CALL lim_cons_final( 'limsbc' ) ! control prints IF( ln_icectl ) CALL lim_prt( kt, iiceprt, jiceprt, 3, ' - Final state lim_sbc - ' ) IF(ln_ctl) THEN CALL prt_ctl( tab2d_1=qsr , clinfo1=' lim_sbc: qsr : ', tab2d_2=qns , clinfo2=' qns : ' ) CALL prt_ctl( tab2d_1=emp , clinfo1=' lim_sbc: emp : ', tab2d_2=sfx , clinfo2=' sfx : ' ) CALL prt_ctl( tab2d_1=fr_i , clinfo1=' lim_sbc: fr_i : ' ) CALL prt_ctl( tab3d_1=tn_ice, clinfo1=' lim_sbc: tn_ice : ', kdim=jpl ) ENDIF END SUBROUTINE lim_sbc_flx SUBROUTINE lim_sbc_tau( kt , pu_oce, pv_oce ) !!------------------------------------------------------------------- !! *** ROUTINE lim_sbc_tau *** !! !! ** Purpose : Update the ocean surface stresses due to the ice !! !! ** Action : * at each ice time step (every nn_fsbc time step): !! - compute the modulus of ice-ocean relative velocity !! (*rho*Cd) at T-point (C-grid) or I-point (B-grid) !! tmod_io = rhoco * | U_ice-U_oce | !! - update the modulus of stress at ocean surface !! taum = frld * taum + (1-frld) * tmod_io * | U_ice-U_oce | !! * at each ocean time step (every kt): !! compute linearized ice-ocean stresses as !! Utau = tmod_io * | U_ice - pU_oce | !! using instantaneous current ocean velocity (usually before) !! !! NB: - ice-ocean rotation angle no more allowed !! - here we make an approximation: taum is only computed every ice time step !! This avoids mutiple average to pass from T -> U,V grids and next from U,V grids !! to T grid. taum is used in TKE and GLS, which should not be too sensitive to this approximaton... !! !! ** Outputs : - utau, vtau : surface ocean i- and j-stress (u- & v-pts) updated with ice-ocean fluxes !! - taum : modulus of the surface ocean stress (T-point) updated with ice-ocean fluxes !!--------------------------------------------------------------------- INTEGER , INTENT(in) :: kt ! ocean time-step index REAL(wp), DIMENSION(jpi,jpj), INTENT(in) :: pu_oce, pv_oce ! surface ocean currents !! INTEGER :: ji, jj ! dummy loop indices REAL(wp) :: zat_u, zutau_ice, zu_t, zmodt ! local scalar REAL(wp) :: zat_v, zvtau_ice, zv_t ! - - !!--------------------------------------------------------------------- ! IF( MOD( kt-1, nn_fsbc ) == 0 ) THEN !== Ice time-step only ==! (i.e. surface module time-step) DO jj = 2, jpjm1 !* update the modulus of stress at ocean surface (T-point) DO ji = fs_2, fs_jpim1 ! ! 2*(U_ice-U_oce) at T-point zu_t = u_ice(ji,jj) + u_ice(ji-1,jj) - u_oce(ji,jj) - u_oce(ji-1,jj) zv_t = v_ice(ji,jj) + v_ice(ji,jj-1) - v_oce(ji,jj) - v_oce(ji,jj-1) ! ! |U_ice-U_oce|^2 zmodt = 0.25_wp * ( zu_t * zu_t + zv_t * zv_t ) ! ! update the ocean stress modulus taum(ji,jj) = ( 1._wp - at_i(ji,jj) ) * taum(ji,jj) + at_i(ji,jj) * rhoco * zmodt tmod_io(ji,jj) = rhoco * SQRT( zmodt ) ! rhoco * |U_ice-U_oce| at T-point END DO END DO CALL lbc_lnk( taum, 'T', 1. ) ; CALL lbc_lnk( tmod_io, 'T', 1. ) ! utau_oce(:,:) = utau(:,:) !* save the air-ocean stresses at ice time-step vtau_oce(:,:) = vtau(:,:) ! ENDIF ! ! !== every ocean time-step ==! ! DO jj = 2, jpjm1 !* update the stress WITHOUT a ice-ocean rotation angle DO ji = fs_2, fs_jpim1 ! Vect. Opt. zat_u = ( at_i(ji,jj) + at_i(ji+1,jj) ) * 0.5_wp ! ice area at u and V-points zat_v = ( at_i(ji,jj) + at_i(ji,jj+1) ) * 0.5_wp ! ! linearized quadratic drag formulation zutau_ice = 0.5_wp * ( tmod_io(ji,jj) + tmod_io(ji+1,jj) ) * ( u_ice(ji,jj) - pu_oce(ji,jj) ) zvtau_ice = 0.5_wp * ( tmod_io(ji,jj) + tmod_io(ji,jj+1) ) * ( v_ice(ji,jj) - pv_oce(ji,jj) ) ! ! stresses at the ocean surface utau(ji,jj) = ( 1._wp - zat_u ) * utau_oce(ji,jj) + zat_u * zutau_ice vtau(ji,jj) = ( 1._wp - zat_v ) * vtau_oce(ji,jj) + zat_v * zvtau_ice END DO END DO CALL lbc_lnk( utau, 'U', -1. ) ; CALL lbc_lnk( vtau, 'V', -1. ) ! lateral boundary condition ! IF(ln_ctl) CALL prt_ctl( tab2d_1=utau, clinfo1=' lim_sbc: utau : ', mask1=umask, & & tab2d_2=vtau, clinfo2=' vtau : ' , mask2=vmask ) ! END SUBROUTINE lim_sbc_tau SUBROUTINE lim_sbc_init !!------------------------------------------------------------------- !! *** ROUTINE lim_sbc_init *** !! !! ** Purpose : Preparation of the file ice_evolu for the output of !! the temporal evolution of key variables !! !! ** input : Namelist namicedia !!------------------------------------------------------------------- INTEGER :: ji, jj, jk ! dummy loop indices REAL(wp) :: zcoefu, zcoefv, zcoeff ! local scalar IF(lwp) WRITE(numout,*) IF(lwp) WRITE(numout,*) 'lim_sbc_init : LIM-3 sea-ice - surface boundary condition' IF(lwp) WRITE(numout,*) '~~~~~~~~~~~~~ ' ! ! allocate lim_sbc array IF( lim_sbc_alloc() /= 0 ) CALL ctl_stop( 'STOP', 'lim_sbc_init : unable to allocate standard arrays' ) ! soce_0(:,:) = soce ! constant SSS and ice salinity used in levitating sea-ice case sice_0(:,:) = sice ! IF( cp_cfg == "orca" ) THEN ! decrease ocean & ice reference salinities in the Baltic sea WHERE( 14._wp <= glamt(:,:) .AND. glamt(:,:) <= 32._wp .AND. & & 54._wp <= gphit(:,:) .AND. gphit(:,:) <= 66._wp ) soce_0(:,:) = 4._wp sice_0(:,:) = 2._wp END WHERE ENDIF ! IF( .NOT. ln_rstart ) THEN ! ! embedded sea ice IF( nn_ice_embd /= 0 ) THEN ! mass exchanges between ice and ocean (case 1 or 2) set the snow+ice mass snwice_mass (:,:) = tmask(:,:,1) * ( rhosn * vt_s(:,:) + rhoic * vt_i(:,:) ) snwice_mass_b(:,:) = snwice_mass(:,:) ELSE snwice_mass (:,:) = 0.0_wp ! no mass exchanges snwice_mass_b(:,:) = 0.0_wp ! no mass exchanges ENDIF IF( nn_ice_embd == 2 ) THEN ! full embedment (case 2) deplete the initial ssh below sea-ice area sshn(:,:) = sshn(:,:) - snwice_mass(:,:) * r1_rau0 sshb(:,:) = sshb(:,:) - snwice_mass(:,:) * r1_rau0 #if defined key_vvl ! key_vvl necessary? clem: yes for compilation purpose DO jk = 1,jpkm1 ! adjust initial vertical scale factors fse3t_n(:,:,jk) = e3t_0(:,:,jk)*( 1._wp + sshn(:,:)*tmask(:,:,1)/(ht_0(:,:) + 1.0 - tmask(:,:,1)) ) fse3t_b(:,:,jk) = e3t_0(:,:,jk)*( 1._wp + sshb(:,:)*tmask(:,:,1)/(ht_0(:,:) + 1.0 - tmask(:,:,1)) ) ENDDO fse3t_a(:,:,:) = fse3t_b(:,:,:) ! Reconstruction of all vertical scale factors at now and before time ! steps ! ============================================================================= ! Horizontal scale factor interpolations ! -------------------------------------- CALL dom_vvl_interpol( fse3t_b(:,:,:), fse3u_b(:,:,:), 'U' ) CALL dom_vvl_interpol( fse3t_b(:,:,:), fse3v_b(:,:,:), 'V' ) CALL dom_vvl_interpol( fse3t_n(:,:,:), fse3u_n(:,:,:), 'U' ) CALL dom_vvl_interpol( fse3t_n(:,:,:), fse3v_n(:,:,:), 'V' ) CALL dom_vvl_interpol( fse3u_n(:,:,:), fse3f_n(:,:,:), 'F' ) ! Vertical scale factor interpolations ! ------------------------------------ CALL dom_vvl_interpol( fse3t_n(:,:,:), fse3w_n (:,:,:), 'W' ) CALL dom_vvl_interpol( fse3u_n(:,:,:), fse3uw_n(:,:,:), 'UW' ) CALL dom_vvl_interpol( fse3v_n(:,:,:), fse3vw_n(:,:,:), 'VW' ) CALL dom_vvl_interpol( fse3u_b(:,:,:), fse3uw_b(:,:,:), 'UW' ) CALL dom_vvl_interpol( fse3v_b(:,:,:), fse3vw_b(:,:,:), 'VW' ) ! t- and w- points depth ! ---------------------- fsdept_n(:,:,1) = 0.5_wp * fse3w_n(:,:,1) fsdepw_n(:,:,1) = 0.0_wp fsde3w_n(:,:,1) = fsdept_n(:,:,1) - sshn(:,:) DO jk = 2, jpk fsdept_n(:,:,jk) = fsdept_n(:,:,jk-1) + fse3w_n(:,:,jk) fsdepw_n(:,:,jk) = fsdepw_n(:,:,jk-1) + fse3t_n(:,:,jk-1) fsde3w_n(:,:,jk) = fsdept_n(:,:,jk ) - sshn (:,:) END DO #endif ENDIF ENDIF ! .NOT. ln_rstart ! END SUBROUTINE lim_sbc_init #else !!---------------------------------------------------------------------- !! Default option : Dummy module NO LIM 3.0 sea-ice model !!---------------------------------------------------------------------- CONTAINS SUBROUTINE lim_sbc ! Dummy routine END SUBROUTINE lim_sbc #endif !!====================================================================== END MODULE limsbc