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 par_ice ! ice parameters USE dom_oce ! ocean domain USE dom_ice, ONLY : tms, area 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 cpl_oasis3, ONLY : lk_cpl USE oce , ONLY : iatte, oatte, sshn, sshb, snwice_mass, snwice_mass_b, snwice_fmass, sshu_b, sshv_b, sshu_n, sshv_n, sshf_n 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 ! clem: add penetration of solar flux into the calculation of heat budget IMPLICIT NONE PRIVATE PUBLIC lim_sbc_init ! called by ice_init PUBLIC lim_sbc_flx ! called by sbc_ice_lim PUBLIC lim_sbc_tau ! called by sbc_ice_lim REAL(wp) :: epsi10 = 1.e-10 ! REAL(wp) :: epsi20 = 1.e-20 ! 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" !!---------------------------------------------------------------------- !! NEMO/LIM3 4.0 , UCL - NEMO Consortium (2011) !! $Id$ !! 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 alberdo (lk_cpl=T) !! !! References : Goosse, H. et al. 1996, Bul. Soc. Roy. Sc. Liege, 65, 87-90. !! Tartinville et al. 2001 Ocean Modelling, 3, 95-108. !!--------------------------------------------------------------------- INTEGER, INTENT(in) :: kt ! number of iteration ! INTEGER :: ji, jj, jl, jk ! dummy loop indices REAL(wp) :: zinda, zemp ! local scalars REAL(wp), POINTER, DIMENSION(:,:,:) :: zalb, zalbp ! 2D/3D workspace REAL(wp) :: ztmelts ! clem 2014: for HC diags REAL(wp) :: zf_mass ! Heat flux associated with mass exchange ice->ocean (W.m-2) REAL(wp) :: zfcm1 ! New solar flux received by the ocean !!--------------------------------------------------------------------- IF( lk_cpl ) CALL wrk_alloc( jpi, jpj, jpl, zalb, zalbp ) ! pfrld is the lead fraction at the previous time step (actually between TRP and THD) DO jj = 1, jpj DO ji = 1, jpi !------------------------------------------! ! heat flux at the ocean surface ! !------------------------------------------! zinda = 1._wp - MAX( 0._wp , SIGN( 1._wp , - ( 1._wp - pfrld(ji,jj) ) ) ) ! 1 if ice ! Solar heat flux reaching the ocean = zfcm1 (W.m-2) !--------------------------------------------------- IF( lk_cpl ) THEN ! be carfeful: not been tested yet ! original line zfcm1 = qsr_tot(ji,jj) !!!zfcm1 = qsr_tot(ji,jj) + ftr_ice(ji,jj) * ( 1._wp - pfrld(ji,jj) ) / ( 1._wp - zinda + zinda * iatte(ji,jj) ) DO jl = 1, jpl zfcm1 = zfcm1 - ( qsr_ice(ji,jj,jl) - ftr_ice(ji,jj,jl) ) * old_a_i(ji,jj,jl) END DO ELSE !!!zfcm1 = pfrld(ji,jj) * qsr(ji,jj) + & !!! & ( 1._wp - pfrld(ji,jj) ) * ftr_ice(ji,jj) / ( 1._wp - zinda + zinda * iatte(ji,jj) ) zfcm1 = pfrld(ji,jj) * qsr(ji,jj) DO jl = 1, jpl zfcm1 = zfcm1 + old_a_i(ji,jj,jl) * ftr_ice(ji,jj,jl) END DO ENDIF ! Total heat flux reaching the ocean = hfx_out (W.m-2) !--------------------------------------------------- zf_mass = 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) + zf_mass + zfcm1 ! New qsr and qns used to compute the oceanic heat flux at the next time step !--------------------------------------------------- qsr(ji,jj) = zfcm1 qns(ji,jj) = hfx_out(ji,jj) - zfcm1 !------------------------------------------! ! 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 ! ! computing freshwater exchanges at the ice/ocean interface ! clem 2014/04: why not 1-pfrld instead of at_i here??? IF( lk_cpl ) THEN zemp = - emp_tot(ji,jj) + emp_ice(ji,jj) * ( 1. - pfrld(ji,jj) ) & ! & - wfx_snw(ji,jj) ELSE zemp = emp(ji,jj) * pfrld(ji,jj) & ! evaporation over oceanic fraction & - tprecip(ji,jj) * ( 1._wp - pfrld(ji,jj) ) & ! all precipitation reach the ocean & + sprecip(ji,jj) * ( 1._wp - pfrld(ji,jj)**betas ) ! except solid precip intercepted by sea-ice ENDIF ! 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) * rdt_ice ! F/M mass flux save at least for biogeochemical model emp(ji,jj) = zemp + wfx_ice(ji,jj) + wfx_snw(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(:,:) !-------------------------------------------------------------! ! 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 (:,:) = tms(:,:) * ( 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 !------------------------------------------------! ! Computation of snow/ice and ocean albedo ! !------------------------------------------------! IF( lk_cpl ) THEN ! coupled case CALL albedo_ice( t_su, ht_i, ht_s, zalbp, zalb ) ! snow/ice albedo alb_ice(:,:,:) = 0.5_wp * zalbp(:,:,:) + 0.5_wp * zalb (:,:,:) ! Ice albedo (mean clear and overcast skys) ENDIF ! ------------------------------------------------- ! C. Rousset Begin Diagnostics for heat in W/m2 ! ------------------------------------------------- DO jj = 1, jpj DO ji = 1, jpi diag_heat_dhc1(ji,jj) = ( SUM( d_e_i_trp(ji,jj,1:nlay_i,:) + d_e_i_thd(ji,jj,1:nlay_i,:) ) + & & SUM( d_e_s_trp(ji,jj,1:nlay_s,:) + d_e_s_thd(ji,jj,1:nlay_s,:) ) ) * unit_fac * r1_rdtice / area(ji,jj) END DO END DO ! ------------------------------------------------- ! C. Rousset End Diagnostics ! ------------------------------------------------- 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 ! IF( lk_cpl ) CALL wrk_dealloc( jpi, jpj, jpl, zalb, zalbp ) ! 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) !CDIR NOVERRCHK DO jj = 2, jpjm1 !* update the modulus of stress at ocean surface (T-point) !CDIR NOVERRCHK 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 !!------------------------------------------------------------------- REAL(wp) :: zsum, zarea ! INTEGER :: ji, jj ! 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 ! clem modif IF( .NOT. ln_rstart ) THEN iatte(:,:) = 1._wp oatte(:,:) = 1._wp ENDIF ! ! clem: snwice_mass in the restart file now 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 (:,:) = tms(:,:) * ( 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 ! ! Note: Changed the initial values of sshb and sshn=> need to recompute ssh[u,v,f]_[b,n] ! which were previously set in domvvl IF ( lk_vvl ) THEN ! Is this necessary? embd 2 should be restricted to vvl only??? DO jj = 1, jpjm1 DO ji = 1, jpim1 ! caution: use of Vector Opt. not possible zcoefu = 0.5 * umask(ji,jj,1) / ( e1u(ji,jj) * e2u(ji,jj) ) zcoefv = 0.5 * vmask(ji,jj,1) / ( e1v(ji,jj) * e2v(ji,jj) ) zcoeff = 0.25 * umask(ji,jj,1) * umask(ji,jj+1,1) sshu_b(ji,jj) = zcoefu * ( e1t(ji ,jj) * e2t(ji ,jj) * sshb(ji ,jj) & & + e1t(ji+1,jj) * e2t(ji+1,jj) * sshb(ji+1,jj) ) sshv_b(ji,jj) = zcoefv * ( e1t(ji,jj ) * e2t(ji,jj ) * sshb(ji,jj ) & & + e1t(ji,jj+1) * e2t(ji,jj+1) * sshb(ji,jj+1) ) sshu_n(ji,jj) = zcoefu * ( e1t(ji ,jj) * e2t(ji ,jj) * sshn(ji ,jj) & & + e1t(ji+1,jj) * e2t(ji+1,jj) * sshn(ji+1,jj) ) sshv_n(ji,jj) = zcoefv * ( e1t(ji,jj ) * e2t(ji,jj ) * sshn(ji,jj ) & & + e1t(ji,jj+1) * e2t(ji,jj+1) * sshn(ji,jj+1) ) END DO END DO CALL lbc_lnk( sshu_b, 'U', 1. ) ; CALL lbc_lnk( sshu_n, 'U', 1. ) CALL lbc_lnk( sshv_b, 'V', 1. ) ; CALL lbc_lnk( sshv_n, 'V', 1. ) DO jj = 1, jpjm1 DO ji = 1, jpim1 ! NO Vector Opt. sshf_n(ji,jj) = 0.5 * umask(ji,jj,1) * umask(ji,jj+1,1) & & / ( e1f(ji,jj ) * e2f(ji,jj ) ) & & * ( e1u(ji,jj ) * e2u(ji,jj ) * sshu_n(ji,jj ) & & + e1u(ji,jj+1) * e2u(ji,jj+1) * sshu_n(ji,jj+1) ) END DO END DO CALL lbc_lnk( sshf_n, 'F', 1. ) 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