MODULE p4zflx !!====================================================================== !! *** MODULE p4zflx *** !! TOP : PISCES CALCULATES GAS EXCHANGE AND CHEMISTRY AT SEA SURFACE !!====================================================================== !! History : - ! 1988-07 (E. MAIER-REIMER) Original code !! - ! 1998 (O. Aumont) additions !! - ! 1999 (C. Le Quere) modifications !! 1.0 ! 2004 (O. Aumont) modifications !! 2.0 ! 2007-12 (C. Ethe, G. Madec) F90 !!---------------------------------------------------------------------- #if defined key_pisces !!---------------------------------------------------------------------- !! 'key_pisces' PISCES bio-model !!---------------------------------------------------------------------- !! p4z_flx : CALCULATES GAS EXCHANGE AND CHEMISTRY AT SEA SURFACE !! p4z_flx_init : Read the namelist !!---------------------------------------------------------------------- USE trc USE oce_trc ! USE trp_trc USE sms USE prtctl_trc USE p4zche IMPLICIT NONE PRIVATE PUBLIC p4z_flx ! called in p4zprg.F90 REAL(wp) :: & ! pre-industrial atmospheric [co2] (ppm) atcox = 0.20946 , & !: atcco2 = 278. !: REAL(wp) :: & xrhoa = 1.22 , & !: Air density kg/m3 xcd = 1.5e-3 !: drag coefficient REAL(wp) :: & tco2flx = 0. !: Total flux of carbon per year !!* Substitution # include "domzgr_substitute.h90" !!---------------------------------------------------------------------- !! NEMO/TOP 2.0 , LOCEAN-IPSL (2007) !! $Header:$ !! Software governed by the CeCILL licence (modipsl/doc/NEMO_CeCILL.txt) !!---------------------------------------------------------------------- CONTAINS SUBROUTINE p4z_flx ( kt ) !!--------------------------------------------------------------------- !! *** ROUTINE p4z_flx *** !! !! ** Purpose : CALCULATES GAS EXCHANGE AND CHEMISTRY AT SEA SURFACE !! !! ** Method : - ??? !!--------------------------------------------------------------------- INTEGER, INTENT(in) :: kt INTEGER :: ji, jj, jrorr, nspyr REAL(wp) :: zttc, ztx, zty, ztau, zws, zkgwan REAL(wp) :: zfld, zflu, zfld16, zflu16, zfact REAL(wp) :: zph, zah2, zbot, zdic, zalk, zschmitto2, zalka, zschmittco2 REAL(wp), DIMENSION(jpi,jpj) :: zkgco2, zkgo2, zh2co3, ztco2flx CHARACTER (len=25) :: charout !!--------------------------------------------------------------------- IF( kt == nittrc000 ) CALL p4z_flx_init ! Initialization (first time-step only) ! ----------------------------------------------------- ! ASSIGNATION TO EXPONENTS IN THE LISS AND MERLIVAT ! FORMULATION OF THE GAS EXCHANGE RATE ! ----------------------------------------------------- nspyr = INT( raass / rdt ) ! SURFACE CHEMISTRY (PCO2 AND [H+] IN ! SURFACE LAYER); THE RESULT OF THIS CALCULATION ! IS USED TO COMPUTE AIR-SEA FLUX OF CO2 DO jrorr = 1, 10 !CDIR NOVERRCHK DO jj = 1, jpj !CDIR NOVERRCHK DO ji = 1, jpi ! DUMMY VARIABLES FOR DIC, H+, AND BORATE zbot = borat(ji,jj,1) zfact = rhop(ji,jj,1) / 1000. + rtrn zdic = trn(ji,jj,1,jpdic) / zfact zph = MAX( hi(ji,jj,1), 1.e-10 ) / zfact zalka = trn(ji,jj,1,jptal) / zfact ! CALCULATE [ALK]([CO3--], [HCO3-]) zalk = zalka - ( akw3(ji,jj,1) / zph - zph + zbot / ( 1.+ zph / akb3(ji,jj,1) ) ) ! CALCULATE [H+] AND [H2CO3] zah2 = SQRT( (zdic-zalk)**2 + 4.* ( zalk * ak23(ji,jj,1) & & / ak13(ji,jj,1) ) * ( 2.* zdic - zalk ) ) zah2 = 0.5 * ak13(ji,jj,1) / zalk * ( ( zdic - zalk ) + zah2 ) zh2co3(ji,jj) = ( 2.* zdic - zalk ) / ( 2.+ ak13(ji,jj,1) / zah2 ) * zfact hi(ji,jj,1) = zah2 * zfact END DO END DO END DO ! -------------- ! COMPUTE FLUXES ! -------------- ! FIRST COMPUTE GAS EXCHANGE COEFFICIENTS ! ------------------------------------------- !CDIR NOVERRCHK DO jj = 1, jpj !CDIR NOVERRCHK DO ji = 1, jpi zttc = MIN( 35., tn(ji,jj,1) ) ! Compute the schmidt Number both O2 and CO2 ! ------------------------------------------ zschmittco2 = 2073.1 - 125.62 * zttc + 3.6276 * zttc**2 - 0.043126 * zttc**3 zschmitto2 = 1953.4 - 128.0 * zttc + 3.9918 * zttc**2 - 0.050091 * zttc**3 ! Estimation of wind speed as a function of wind stress ztx = utau(ji,jj) * umask(ji,jj,1) zty = vtau(ji,jj) * vmask(ji,jj,1) ztau = SQRT( ztx * ztx + zty * zty ) zws = SQRT ( ztau / ( xrhoa * xcd ) ) ! Compute the piston velocity for O2 and CO2 ! ------------------------------------------ zkgwan = ( 0.3 * zws * zws & & + 2.5 * ( 0.5246 + zttc * ( 0.016256+zttc*0.00049946 ) ) ) & # if defined key_off_degrad & * facvol(ji,jj,1) & # endif & / (100. * 3600.)* ( 1.- freeze(ji,jj) ) * tmask(ji,jj,1) ! COMPUTE GAS EXCHANGE FOR CO2 zkgco2(ji,jj) = zkgwan * SQRT( 660./ zschmittco2 ) zkgo2(ji,jj) = zkgwan * SQRT( 660./ zschmitto2 ) END DO END DO ztco2flx(:,:) = 0. DO jj = 1, jpj DO ji = 1, jpi ! Compute CO2 flux for the sea and air zfld = atcco2 * tmask(ji,jj,1) * chemc(ji,jj,1) * zkgco2(ji,jj) zflu = zh2co3(ji,jj) * tmask(ji,jj,1) * zkgco2(ji,jj) tra(ji,jj,1,jpdic) = tra(ji,jj,1,jpdic) + ( zfld - zflu ) / fse3t(ji,jj,1) ! compute flux of carbon ztco2flx(ji,jj) = ( zfld - zflu ) * rfact & & * e1t(ji,jj) * e2t(ji,jj) * tmask(ji,jj,1) * 1000. ! Compute O2 flux zfld16 = atcox * chemc(ji,jj,2) *tmask(ji,jj,1) * zkgo2(ji,jj) zflu16 = trn(ji,jj,1,jpoxy) * tmask(ji,jj,1) * zkgo2(ji,jj) tra(ji,jj,1,jpoxy) = tra(ji,jj,1,jpoxy) + ( zfld16 - zflu16 ) / fse3t(ji,jj,1) # if defined key_trc_diaadd ! Save diagnostics trc2d(ji,jj,1) = ( zfld - zflu ) * 1000. trc2d(ji,jj,2) = ( zfld16 - zflu16 ) * 1000. trc2d(ji,jj,3) = zkgco2(ji,jj) trc2d(ji,jj,4) = atcco2 - zh2co3(ji,jj) / ( chemc(ji,jj,1) + rtrn ) # endif END DO END DO ! ! Total Flux of Carbon DO jj = 1, jpj DO ji = 1, jpi tco2flx = tco2flx + ztco2flx(ji,jj) * tmask_i(ji,jj) END DO END DO IF( MOD( kt, nspyr ) == 0 ) THEN WRITE(numout,*) ' Atmospheric pCO2 :' WRITE(numout,*) '-------------------- : ',kt,' ',atcco2 WRITE(numout,*) '(ppm)' WRITE(numout,*) 'Total Flux of Carbon :' WRITE(numout,*) '-------------------- : ',tco2flx * 12./1E15 WRITE(numout,*) '(GtC/an)' tco2flx = 0. ENDIF IF(ln_ctl) THEN ! print mean trends (used for debugging) WRITE(charout, FMT="('flx ')") CALL prt_ctl_trc_info(charout) CALL prt_ctl_trc(tab4d=tra, mask=tmask, clinfo=ctrcnm) ENDIF END SUBROUTINE p4z_flx SUBROUTINE p4z_flx_init !!---------------------------------------------------------------------- !! *** ROUTINE p4z_flx_init *** !! !! ** Purpose : Initialization of atmospheric conditions !! !! ** Method : Read the natext namelist and check the parameters !! called at the first timestep (nittrc000) !! ** input : Namelist natext !! !!---------------------------------------------------------------------- NAMELIST/natext/ atcco2 REWIND( numnat ) ! read numnat READ ( numnat, natext ) IF(lwp) THEN ! control print WRITE(numout,*) ' ' WRITE(numout,*) ' Namelist parameters for air-sea exchange, natext' WRITE(numout,*) ' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~' WRITE(numout,*) ' Atmospheric pCO2 atcco2 =', atcco2 ENDIF END SUBROUTINE p4z_flx_init #else !!====================================================================== !! Dummy module : No PISCES bio-model !!====================================================================== CONTAINS SUBROUTINE p4z_flx( kt ) ! Empty routine INTEGER, INTENT( in ) :: kt WRITE(*,*) 'p4z_flx: You should not have seen this print! error?', kt END SUBROUTINE p4z_flx #endif !!====================================================================== END MODULE p4zflx