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 phycst USE ocfzpt USE ice_oce USE flx_oce USE ice USE flxblk USE lbclnk USE in_out_manager IMPLICIT NONE PRIVATE !! * Routine accessibility PUBLIC lim_flx ! called by lim_step !! * Module variables REAL(wp) :: & ! constant values epsi16 = 1e-16 , & rzero = 0.0 , & rone = 1.0 !! * Substitutions # include "vectopt_loop_substitute.h90" !!---------------------------------------------------------------------- !! LIM 2.0 , UCL-LODYC-IPSL (2003) !!---------------------------------------------------------------------- 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) !!--------------------------------------------------------------------- !! * Modules used !! * 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 zfons, & ! salt exchanges at the ice/ocean interface zpme ! freshwater exchanges at the ice/ocean interface #else 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 zinda = 1.0 - MAX( rzero , SIGN( rone , - ( 1.0 - pfrld(ji,jj) ) ) ) ifvt = zinda * MAX( rzero , SIGN( rone, -phicif(ji,jj) ) ) i1mfr = 1.0 - MAX( rzero , SIGN( rone , - ( 1.0 - frld(ji,jj) ) ) ) idfr = 1.0 - MAX( rzero , SIGN( rone , frld(ji,jj) - pfrld(ji,jj) ) ) iflt = zinda * (1 - i1mfr) * (1 - ifvt ) ial = ifvt * i1mfr + ( 1 - ifvt ) * idfr iadv = ( 1 - i1mfr ) * zinda ifral = ( 1 - i1mfr * ( 1 - ial ) ) ifrdv = ( 1 - ifral * ( 1 - ial ) ) * iadv 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 ! !-----------------------------------------------! DO jj = 1, jpj DO ji = 1, jpi ftaux (ji,jj) = - tio_u(ji,jj) * rau0 ! taux ( ice: N/m2/rau0, ocean: N/m2 ) ftauy (ji,jj) = - tio_v(ji,jj) * rau0 ! tauy ( ice: N/m2/rau0, ocean: N/m2 ) freeze(ji,jj) = 1.0 - frld(ji,jj) ! Sea ice cover tn_ice(ji,jj) = sist(ji,jj) ! Ice surface temperature END DO END DO #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 ) DO jj = 1, jpj DO ji = 1, jpi alb_ice(ji,jj) = 0.5 * zalbp(ji,jj) + 0.5 * zalb (ji,jj) ! Ice albedo END DO END DO #endif IF( l_ctl .AND. lwp ) THEN WRITE(numout,*) ' lim_flx ' WRITE(numout,*) ' fsolar ', SUM(fsolar), ' fnsolar', SUM( fnsolar ) WRITE(numout,*) ' fmass ', SUM(fmass ), ' fsalt ', SUM(fsalt) WRITE(numout,*) ' ftaux ', SUM(ftaux ), ' ftauy ', SUM(ftauy) WRITE(numout,*) ' freeze ', SUM(freeze), ' tn_ice ', SUM(tn_ice) ENDIF END SUBROUTINE lim_flx #else !!---------------------------------------------------------------------- !! Default option : Empty module NO LIM sea-ice model !!---------------------------------------------------------------------- CONTAINS SUBROUTINE lim_flx ! Empty routine END SUBROUTINE lim_flx #endif END MODULE limflx