MODULE limflx !!====================================================================== !! *** MODULE limflx *** !! computation of the flux at the sea ice/ocean interface !!====================================================================== #if defined key_ice_lim !!---------------------------------------------------------------------- !! 'key_ice_lim' LIM sea-ice model !!---------------------------------------------------------------------- !! lim_flx : flux at the ice / ocean interface !!---------------------------------------------------------------------- !! * Modules used USE par_oce ! ocean parameters USE phycst ! physical constants USE ocfzpt ! surface ocean freezing point USE ice_oce ! sea-ice variable USE flx_oce ! sea-ice/ocean forcings variables USE ice ! LIM sea-ice variables USE flxblk ! bulk formulea USE lbclnk ! ocean lateral boundary condition USE in_out_manager ! I/O manager USE albedo ! albedo parameters USE prtctl ! Print control IMPLICIT NONE PRIVATE !! * Routine accessibility PUBLIC lim_flx ! called by lim_step !! * Module variables REAL(wp) :: & ! constant values epsi16 = 1.e-16 , & rzero = 0.e0 , & rone = 1.e0 !! * Substitutions # include "vectopt_loop_substitute.h90" !!---------------------------------------------------------------------- !! LIM 2.0, UCL-LOCEAN-IPSL (2005) !! $Id$ !! This software is governed by the CeCILL licence see modipsl/doc/NEMO_CeCILL.txt !!---------------------------------------------------------------------- CONTAINS SUBROUTINE lim_flx !!------------------------------------------------------------------- !! *** ROUTINE lim_flx *** !! !! ** Purpose : Computes the mass and heat fluxes to the ocean !! !! ** Action : - Initialisation of some variables !! - comput. of the fluxes at the sea ice/ocean interface !! !! ** Outputs : - fsolar : solar heat flux at sea ice/ocean interface !! - fnsolar : non solar heat flux !! - fsalt : salt flux at sea ice/ocean interface !! - fmass : freshwater flux at sea ice/ocean interface !! !! ** References : !! H. Goosse et al. 1996, Bul. Soc. Roy. Sc. Liege, 65, 87-90 !! original : 00-01 (LIM) !! addition : 02-07 (C. Ethe, G. Madec) !!--------------------------------------------------------------------- !! * Local variables INTEGER :: ji, jj ! dummy loop indices INTEGER :: & ifvt, i1mfr, idfr , & ! some switches iflt, ial, iadv, ifral, ifrdv REAL(wp) :: & zinda , & ! switch for testing the values of ice concentration z1mthcm ! 1 - thcm !! zfcm1 , & ! solar heat fluxes !! zfcm2 , & ! non solar heat fluxes #if defined key_lim_fdd REAL(wp) :: & zfons, & ! salt exchanges at the ice/ocean interface zpme ! freshwater exchanges at the ice/ocean interface #else REAL(wp) :: & zprs , zfons, & ! salt exchanges at the ice/ocean interface zpmess ! freshwater exchanges at the ice/ocean interface #endif REAL(wp), DIMENSION(jpi,jpj) :: & zfcm1 , & ! solar heat fluxes zfcm2 ! non solar heat fluxes #if defined key_coupled REAL(wp), DIMENSION(jpi,jpj) :: & zalb , & ! albedo of ice under overcast sky zalcn , & ! albedo of ocean under overcast sky zalbp , & ! albedo of ice under clear sky zaldum ! albedo of ocean under clear sky #endif !!--------------------------------------------------------------------- !---------------------------------! ! Sea ice/ocean interface ! !---------------------------------! ! heat flux at the ocean surface !------------------------------------------------------- DO jj = 1, jpj DO ji = 1, jpi !!sm zinda = 1.0 - MAX( rzero , SIGN( rone , - ( 1.0 - pfrld(ji,jj) ) ) ) !!sm ifvt = zinda * MAX( rzero , SIGN( rone, -phicif(ji,jj) ) ) !!sm i1mfr = 1.0 - MAX( rzero , SIGN( rone , - ( 1.0 - frld(ji,jj) ) ) ) !!sm idfr = 1.0 - MAX( rzero , SIGN( rone , frld(ji,jj) - pfrld(ji,jj) ) ) zinda = 1.0 - AINT( pfrld(ji,jj) ) ! = 0. if pure ocean else 1. (at previous time) i1mfr = 1.0 - AINT( frld(ji,jj) ) ! = 0. if pure ocean else 1. (at current time) IF( phicif(ji,jj) <= 0. ) THEN ; ifvt = zinda ! = 1. if (snow and no ice at previous time) else 0. ??? ELSE ; ifvt = 0. ENDIF IF( frld(ji,jj) >= pfrld(ji,jj) ) THEN ; idfr = 0. ! = 0. if lead fraction increases from previous to current ELSE ; idfr = 1. ENDIF iflt = zinda * (1 - i1mfr) * (1 - ifvt ) ! = 1. if ice (not only snow) at previous and pure ocean at current ial = ifvt * i1mfr + ( 1 - ifvt ) * idfr ! snow no ice ice ice or nothing lead fraction increases ! at previous now at previous ! -> ice aera increases ??? -> ice aera decreases ??? iadv = ( 1 - i1mfr ) * zinda ! pure ocean ice at ! at current previous ! -> = 1. if ice disapear between previous and current ifral = ( 1 - i1mfr * ( 1 - ial ) ) ! ice at ??? ! current ! -> ??? ifrdv = ( 1 - ifral * ( 1 - ial ) ) * iadv ! ice disapear ! ! z1mthcm = 1. - thcm(ji,jj) ! computation the solar flux at ocean surface zfcm1(ji,jj) = pfrld(ji,jj) * qsr_oce(ji,jj) + ( 1. - pfrld(ji,jj) ) * fstric(ji,jj) ! computation the non solar heat flux at ocean surface zfcm2(ji,jj) = - z1mthcm * zfcm1(ji,jj) & & + iflt * ( fscmbq(ji,jj) + ffltbif(ji,jj) ) & & + ifral * ( ial * qcmif(ji,jj) + (1 - ial) * qldif(ji,jj) ) / rdt_ice & & + ifrdv * ( qfvbq(ji,jj) + qdtcn(ji,jj) ) / rdt_ice fsbbq(ji,jj) = ( 1.0 - ( ifvt + iflt ) ) * fscmbq(ji,jj) ! ??? fsolar (ji,jj) = zfcm1(ji,jj) ! solar heat flux fnsolar(ji,jj) = zfcm2(ji,jj) - fdtcn(ji,jj) ! non solar heat flux END DO END DO ! mass flux at the ocean surface !------------------------------------------------------- DO jj = 1, jpj DO ji = 1, jpi #if defined key_lim_fdd ! case of realistic freshwater flux (Tartinville et al., 2001) ! computing freshwater exchanges at the ice/ocean interface zpme = - evap(ji,jj) * frld(ji,jj) & ! evaporation over oceanic fraction & + tprecip(ji,jj) & ! total precipitation & - sprecip(ji,jj) * ( 1. - pfrld(ji,jj) ) & ! remov. snow precip over ice & - rdmsnif(ji,jj) / rdt_ice ! freshwaterflux due to snow melting ! computing salt exchanges at the ice/ocean interface zfons = ( soce - sice ) * ( rdmicif(ji,jj) / rdt_ice ) ! converting the salt flux from ice to a freshwater flux from ocean fsalt(ji,jj) = zfons / ( sss_io(ji,jj) + epsi16 ) ! freshwater masses fmass(ji,jj) = - zpme #else ! case of freshwater flux equivalent as salt flux ! dilution effect due to evaporation and precipitation zprs = ( tprecip(ji,jj) - sprecip(ji,jj) * ( 1. - pfrld(ji,jj) ) ) * soce ! freshwater flux zfons = rdmicif(ji,jj) * ( soce - sice ) & ! fwf : ice formation and melting & - dmgwi(ji,jj) * sice & ! fwf : salt flx needed to bring the fresh snow to sea/ice salinity & + rdmsnif(ji,jj) * soce ! fwf to ocean due to snow melting ! salt exchanges at the ice/ocean interface zpmess = zprs - zfons / rdt_ice - evap(ji,jj) * soce * frld(ji,jj) fsalt(ji,jj) = - zpmess #endif END DO END DO !-------------------------------------------------------------------! ! computation of others transmitting variables from ice to ocean ! !------------------------------------------ ------------------------! !-----------------------------------------------! ! Storing the transmitted variables ! !-----------------------------------------------! freeze(:,:) = 1.0 - frld(:,:) ! Sea ice cover tn_ice(:,:) = sist(:,:) ! Ice surface temperature #if defined key_coupled zalb (:,:) = 0.e0 zalcn (:,:) = 0.e0 zalbp (:,:) = 0.e0 zaldum(:,:) = 0.e0 !------------------------------------------------! ! 2) Computation of snow/ice and ocean albedo ! !------------------------------------------------! CALL flx_blk_albedo( zalb, zalcn, zalbp, zaldum ) alb_ice(:,:) = 0.5 * zalbp(:,:) + 0.5 * zalb (:,:) ! Ice albedo #endif IF(ln_ctl) THEN CALL prt_ctl(tab2d_1=fsolar, clinfo1=' lim_flx: fsolar : ', tab2d_2=fnsolar, clinfo2=' fnsolar : ') CALL prt_ctl(tab2d_1=fmass , clinfo1=' lim_flx: fmass : ', tab2d_2=fsalt , clinfo2=' fsalt : ') CALL prt_ctl(tab2d_1=freeze, clinfo1=' lim_flx: freeze : ', tab2d_2=tn_ice , clinfo2=' tn_ice : ') ENDIF END SUBROUTINE lim_flx #else !!---------------------------------------------------------------------- !! Default option : Dummy module NO LIM sea-ice model !!---------------------------------------------------------------------- CONTAINS SUBROUTINE lim_flx ! Dummy routine END SUBROUTINE lim_flx #endif !!====================================================================== END MODULE limflx