MODULE iceupdate !!====================================================================== !! *** MODULE iceupdate *** !! 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 !!---------------------------------------------------------------------- !! ice_update_alloc : allocate the iceupdate arrays !! ice_update_init : initialisation !! ice_update_flx : updates mass, heat and salt fluxes at the ocean surface !! ice_update_tau : update i- and j-stresses, and its modulus at the ocean surface !!---------------------------------------------------------------------- USE par_oce ! ocean parameters USE oce , ONLY : sshn, sshb USE phycst ! physical constants USE dom_oce ! ocean domain USE ice ! LIM sea-ice variables USE sbc_ice , ONLY : emp_oce, qns_oce, qsr_oce, qemp_oce, emp_ice, qsr_ice, qemp_ice, qevap_ice, alb_ice, tn_ice, cldf_ice, & & snwice_mass, snwice_mass_b, snwice_fmass USE sbc_oce , ONLY : nn_fsbc, ln_ice_embd, sfx, fr_i, qsr_tot, qns, qsr, fmmflx, emp, taum, utau, vtau USE sbccpl ! Surface boundary condition: coupled interface USE icealbedo ! albedo parameters USE traqsr ! add penetration of solar flux in the calculation of heat budget USE domvvl ! Variable volume USE icectl ! USE icecons ! USE bdy_oce , ONLY: ln_bdy ! USE in_out_manager ! I/O manager USE iom ! xIO server USE lbclnk ! ocean lateral boundary condition - MPP exchanges USE lib_mpp ! MPP library USE lib_fortran ! Fortran utilities (allows no signed zero when 'key_nosignedzero' defined) IMPLICIT NONE PRIVATE PUBLIC ice_update_init ! called by ice_init PUBLIC ice_update_flx ! called by ice_stp PUBLIC ice_update_tau ! called by ice_stp 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: iceupdate.F90 8411 2017-08-07 16:09:12Z clem $ !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) !!---------------------------------------------------------------------- CONTAINS INTEGER FUNCTION ice_update_alloc() !!------------------------------------------------------------------- !! *** ROUTINE ice_update_alloc *** !!------------------------------------------------------------------- ALLOCATE( soce_0(jpi,jpj) , utau_oce(jpi,jpj) , & & sice_0(jpi,jpj) , vtau_oce(jpi,jpj) , tmod_io(jpi,jpj), STAT=ice_update_alloc) ! IF( lk_mpp ) CALL mpp_sum( ice_update_alloc ) IF( ice_update_alloc /= 0 ) CALL ctl_warn('ice_update_alloc: failed to allocate arrays') END FUNCTION ice_update_alloc SUBROUTINE ice_update_flx( kt ) !!------------------------------------------------------------------- !! *** ROUTINE ice_update_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), DIMENSION(jpi,jpj,jpl) :: zalb_cs, zalb_os ! 3D workspace !!--------------------------------------------------------------------- ! --- case we bypass ice thermodynamics --- ! IF( .NOT. ln_limthd ) THEN ! we suppose ice is impermeable => ocean is isolated from atmosphere hfx_in (:,:) = ( 1._wp - at_i_b(:,:) ) * ( qns_oce(:,:) + qsr_oce(:,:) ) + qemp_oce(:,:) hfx_out (:,:) = ( 1._wp - at_i_b(:,:) ) * qns_oce(:,:) + qemp_oce(:,:) ftr_ice (:,:,:) = 0._wp emp_ice (:,:) = 0._wp qemp_ice (:,:) = 0._wp qevap_ice(:,:,:) = 0._wp ENDIF 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 atm. surface !----------------------------------- wfx_sub(ji,jj) = wfx_snw_sub(ji,jj) + wfx_ice_sub(ji,jj) ! 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) + wfx_lam(ji,jj) IF ( ln_pnd_fw ) wfx_ice(ji,jj) = wfx_ice(ji,jj) + wfx_pnd(ji,jj) ! add the snow melt water to snow mass flux to the ocean wfx_snw(ji,jj) = wfx_snw_sni(ji,jj) + wfx_snw_dyn(ji,jj) + wfx_snw_sum(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) ! Salt flux at the ocean surface !------------------------------------------ sfx(ji,jj) = sfx_bog(ji,jj) + sfx_bom(ji,jj) + sfx_sum(ji,jj) + sfx_sni(ji,jj) + sfx_opw(ji,jj) & & + sfx_res(ji,jj) + sfx_dyn(ji,jj) + sfx_bri(ji,jj) + sfx_sub(ji,jj) + sfx_lam(ji,jj) ! Mass of snow and ice per unit area !---------------------------------------- ! save mass from the previous ice time step snwice_mass_b(ji,jj) = snwice_mass(ji,jj) ! new mass per unit area snwice_mass (ji,jj) = tmask(ji,jj,1) * ( rhosn * vt_s(ji,jj) + rhoic * vt_i(ji,jj) ) ! time evolution of snow+ice mass snwice_fmass (ji,jj) = ( snwice_mass(ji,jj) - snwice_mass_b(ji,jj) ) * r1_rdtice END DO END DO !-----------------------------------------------! ! 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 ice_albedo( t_su, ht_i, ht_s, a_ip_frac, h_ip, ln_pnd_rad, zalb_cs, zalb_os ) ! cloud-sky and overcast-sky ice albedos alb_ice(:,:,:) = ( 1. - cldf_ice ) * zalb_cs(:,:,:) + cldf_ice * zalb_os(:,:,:) ! conservation test IF( ln_limdiachk .AND. .NOT. ln_bdy) CALL ice_cons_final( 'iceupdate' ) ! control prints IF( ln_limctl ) CALL ice_prt( kt, iiceprt, jiceprt, 3, ' - Final state ice_update - ' ) IF( ln_ctl ) CALL ice_prt3D( 'iceupdate' ) END SUBROUTINE ice_update_flx SUBROUTINE ice_update_tau( kt , pu_oce, pv_oce ) !!------------------------------------------------------------------- !! *** ROUTINE ice_update_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 = (1-a) * taum + a * 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, zrhoco ! - - !!--------------------------------------------------------------------- zrhoco = rau0 * rn_cio ! 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) * zrhoco * zmodt tmod_io(ji,jj) = zrhoco * SQRT( zmodt ) ! rhoco * |U_ice-U_oce| at T-point END DO END DO CALL lbc_lnk_multi( taum, 'T', 1., 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_multi( utau, 'U', -1., vtau, 'V', -1. ) ! lateral boundary condition ! ! END SUBROUTINE ice_update_tau SUBROUTINE ice_update_init !!------------------------------------------------------------------- !! *** ROUTINE ice_update_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,*) 'ice_update_init : LIM-3 sea-ice - surface boundary condition' IF(lwp) WRITE(numout,*) '~~~~~~~~~~~~~ ' ! ! allocate ice_update array IF( ice_update_alloc() /= 0 ) CALL ctl_stop( 'STOP', 'ice_update_init : unable to allocate standard arrays' ) ! soce_0(:,:) = soce ! constant SSS and ice salinity used in levitating sea-ice case sice_0(:,:) = sice ! ! decrease ocean & ice reference salinities in the Baltic Sea area 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 ! IF( .NOT. ln_rstart ) THEN ! snwice_mass (:,:) = tmask(:,:,1) * ( rhosn * vt_s(:,:) + rhoic * vt_i(:,:) ) ! snow+ice mass snwice_mass_b(:,:) = snwice_mass(:,:) ! IF( ln_ice_embd ) THEN ! embedded sea-ice: deplete the initial ssh below sea-ice area sshn(:,:) = sshn(:,:) - snwice_mass(:,:) * r1_rau0 sshb(:,:) = sshb(:,:) - snwice_mass(:,:) * r1_rau0 !!gm I really don't like this stuff here... Find a way to put that elsewhere or differently !!gm IF( .NOT.ln_linssh ) THEN DO jk = 1,jpkm1 ! adjust initial vertical scale factors e3t_n(:,:,jk) = e3t_0(:,:,jk)*( 1._wp + sshn(:,:)*tmask(:,:,1)/(ht_0(:,:) + 1.0 - tmask(:,:,1)) ) e3t_b(:,:,jk) = e3t_0(:,:,jk)*( 1._wp + sshb(:,:)*tmask(:,:,1)/(ht_0(:,:) + 1.0 - tmask(:,:,1)) ) END DO e3t_a(:,:,:) = e3t_b(:,:,:) ! Reconstruction of all vertical scale factors at now and before time-steps ! ========================================================================= ! Horizontal scale factor interpolations ! -------------------------------------- CALL dom_vvl_interpol( e3t_b(:,:,:), e3u_b(:,:,:), 'U' ) CALL dom_vvl_interpol( e3t_b(:,:,:), e3v_b(:,:,:), 'V' ) CALL dom_vvl_interpol( e3t_n(:,:,:), e3u_n(:,:,:), 'U' ) CALL dom_vvl_interpol( e3t_n(:,:,:), e3v_n(:,:,:), 'V' ) CALL dom_vvl_interpol( e3u_n(:,:,:), e3f_n(:,:,:), 'F' ) ! Vertical scale factor interpolations ! ------------------------------------ CALL dom_vvl_interpol( e3t_n(:,:,:), e3w_n (:,:,:), 'W' ) CALL dom_vvl_interpol( e3u_n(:,:,:), e3uw_n(:,:,:), 'UW' ) CALL dom_vvl_interpol( e3v_n(:,:,:), e3vw_n(:,:,:), 'VW' ) CALL dom_vvl_interpol( e3u_b(:,:,:), e3uw_b(:,:,:), 'UW' ) CALL dom_vvl_interpol( e3v_b(:,:,:), e3vw_b(:,:,:), 'VW' ) ! t- and w- points depth ! ---------------------- !!gm not sure of that.... gdept_n(:,:,1) = 0.5_wp * e3w_n(:,:,1) gdepw_n(:,:,1) = 0.0_wp gde3w_n(:,:,1) = gdept_n(:,:,1) - sshn(:,:) DO jk = 2, jpk gdept_n(:,:,jk) = gdept_n(:,:,jk-1) + e3w_n(:,:,jk) gdepw_n(:,:,jk) = gdepw_n(:,:,jk-1) + e3t_n(:,:,jk-1) gde3w_n(:,:,jk) = gdept_n(:,:,jk ) - sshn (:,:) END DO ENDIF ENDIF ENDIF ! .NOT. ln_rstart ! END SUBROUTINE ice_update_init #else !!---------------------------------------------------------------------- !! Default option : Dummy module NO LIM 3.0 sea-ice model !!---------------------------------------------------------------------- CONTAINS SUBROUTINE ice_update ! Dummy routine END SUBROUTINE ice_update #endif !!====================================================================== END MODULE iceupdate