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 !! ! 2011-02 (J. Simeon, J. Orr) Include total atm P correction !!---------------------------------------------------------------------- !! p4z_flx : CALCULATES GAS EXCHANGE AND CHEMISTRY AT SEA SURFACE !! p4z_flx_init : Read the namelist !! p4z_patm : Read sfc atm pressure [atm] for each grid cell !!---------------------------------------------------------------------- USE oce_trc ! shared variables between ocean and passive tracers USE trc ! passive tracers common variables USE sms_pisces ! PISCES Source Minus Sink variables USE p4zche ! Chemical model USE prtctl_trc ! print control for debugging USE iom ! I/O manager USE fldread ! read input fields IMPLICIT NONE PRIVATE PUBLIC p4z_flx PUBLIC p4z_flx_init PUBLIC p4z_flx_alloc ! !!** Namelist nampisext ** REAL(wp) :: atcco2 !: pre-industrial atmospheric [co2] (ppm) LOGICAL :: ln_co2int !: flag to read in a file and interpolate atmospheric pco2 or not CHARACTER(len=34) :: clname !: filename of pco2 values INTEGER :: nn_offset !: Offset model-data start year (default = 0) !! Variables related to reading atmospheric CO2 time history INTEGER :: nmaxrec, numco2 ! REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:) :: atcco2h, years ! ! !!* nampisatm namelist (Atmospheric PRessure) * LOGICAL, PUBLIC :: ln_presatm !: ref. pressure: global mean Patm (F) or a constant (F) LOGICAL, PUBLIC :: ln_presatmco2 !: accounting for spatial atm CO2 in the compuation of carbon flux (T) or not (F) REAL(wp) , ALLOCATABLE, SAVE, DIMENSION(:,:) :: patm ! atmospheric pressure at kt [N/m2] TYPE(FLD), ALLOCATABLE, DIMENSION(:) :: sf_patm ! structure of input fields (file informations, fields read) TYPE(FLD), ALLOCATABLE, DIMENSION(:) :: sf_atmco2 ! structure of input fields (file informations, fields read) REAL(wp), PUBLIC, ALLOCATABLE, SAVE, DIMENSION(:,:) :: satmco2 !: atmospheric pco2 REAL(wp) :: xconv = 0.01_wp / 3600._wp !: coefficients for conversion !!---------------------------------------------------------------------- !! NEMO/TOP 4.0 , NEMO Consortium (2018) !! $Id$ !! Software governed by the CeCILL license (see ./LICENSE) !!---------------------------------------------------------------------- CONTAINS SUBROUTINE p4z_flx ( kt, knt ) !!--------------------------------------------------------------------- !! *** ROUTINE p4z_flx *** !! !! ** Purpose : CALCULATES GAS EXCHANGE AND CHEMISTRY AT SEA SURFACE !! !! ** Method : !! - Include total atm P correction via Esbensen & Kushnir (1981) !! - Remove Wanninkhof chemical enhancement; !! - Add option for time-interpolation of atcco2.txt !!--------------------------------------------------------------------- INTEGER, INTENT(in) :: kt, knt ! ! INTEGER :: ji, jj, jm, iind, iindm1 REAL(wp) :: ztc, ztc2, ztc3, ztc4, zws, zkgwan REAL(wp) :: zfld, zflu, zfld16, zflu16, zfact REAL(wp) :: zvapsw, zsal, zfco2, zxc2, xCO2approx, ztkel, zfugcoeff REAL(wp) :: zph, zdic, zsch_o2, zsch_co2 REAL(wp) :: zyr_dec, zdco2dt CHARACTER (len=25) :: charout REAL(wp), DIMENSION(jpi,jpj) :: zkgco2, zkgo2, zh2co3, zoflx, zpco2atm REAL(wp), ALLOCATABLE, DIMENSION(:,:) :: zw2d !!--------------------------------------------------------------------- ! IF( ln_timing ) CALL timing_start('p4z_flx') ! ! SURFACE CHEMISTRY (PCO2 AND [H+] IN ! SURFACE LAYER); THE RESULT OF THIS CALCULATION ! IS USED TO COMPUTE AIR-SEA FLUX OF CO2 IF( kt /= nit000 .AND. .NOT.l_co2cpl .AND. knt == 1 ) CALL p4z_patm( kt ) ! Get sea-level pressure (E&K [1981] climatology) for use in flux calcs IF( ln_co2int .AND. .NOT.ln_presatmco2 .AND. .NOT.l_co2cpl ) THEN ! Linear temporal interpolation of atmospheric pco2. atcco2.txt has annual values. ! Caveats: First column of .txt must be in years, decimal years preferably. ! For nn_offset, if your model year is iyy, nn_offset=(years(1)-iyy) ! then the first atmospheric CO2 record read is at years(1) zyr_dec = REAL( nyear + nn_offset, wp ) + REAL( nday_year, wp ) / REAL( nyear_len(1), wp ) jm = 1 DO WHILE( jm <= nmaxrec .AND. years(jm) < zyr_dec ) ; jm = jm + 1 ; END DO iind = jm ; iindm1 = jm - 1 zdco2dt = ( atcco2h(iind) - atcco2h(iindm1) ) / ( years(iind) - years(iindm1) + rtrn ) atcco2 = zdco2dt * ( zyr_dec - years(iindm1) ) + atcco2h(iindm1) satmco2(:,:) = atcco2 ENDIF IF( l_co2cpl ) satmco2(:,:) = atm_co2(:,:) DO jj = 1, jpj DO ji = 1, jpi ! DUMMY VARIABLES FOR DIC, H+, AND BORATE zfact = rhop(ji,jj,1) / 1000. + rtrn zdic = trb(ji,jj,1,jpdic) zph = MAX( hi(ji,jj,1), 1.e-10 ) / zfact ! CALCULATE [H2CO3] zh2co3(ji,jj) = zdic/(1. + ak13(ji,jj,1)/zph + ak13(ji,jj,1)*ak23(ji,jj,1)/zph**2) END DO END DO ! -------------- ! COMPUTE FLUXES ! -------------- ! FIRST COMPUTE GAS EXCHANGE COEFFICIENTS ! ------------------------------------------- DO jj = 1, jpj DO ji = 1, jpi ztc = MIN( 35., tsn(ji,jj,1,jp_tem) ) ztc2 = ztc * ztc ztc3 = ztc * ztc2 ztc4 = ztc2 * ztc2 ! Compute the schmidt Number both O2 and CO2 zsch_co2 = 2116.8 - 136.25 * ztc + 4.7353 * ztc2 - 0.092307 * ztc3 + 0.0007555 * ztc4 zsch_o2 = 1920.4 - 135.6 * ztc + 5.2122 * ztc2 - 0.109390 * ztc3 + 0.0009377 * ztc4 ! wind speed zws = wndm(ji,jj) * wndm(ji,jj) ! Compute the piston velocity for O2 and CO2 zkgwan = 0.251 * zws zkgwan = zkgwan * xconv * ( 1.- fr_i(ji,jj) ) * tmask(ji,jj,1) ! compute gas exchange for CO2 and O2 zkgco2(ji,jj) = zkgwan * SQRT( 660./ zsch_co2 ) zkgo2 (ji,jj) = zkgwan * SQRT( 660./ zsch_o2 ) END DO END DO DO jj = 1, jpj DO ji = 1, jpi ztkel = tempis(ji,jj,1) + 273.15 zsal = salinprac(ji,jj,1) + ( 1.- tmask(ji,jj,1) ) * 35. zvapsw = EXP(24.4543 - 67.4509*(100.0/ztkel) - 4.8489*LOG(ztkel/100) - 0.000544*zsal) zpco2atm(ji,jj) = satmco2(ji,jj) * ( patm(ji,jj) - zvapsw ) zxc2 = ( 1.0 - zpco2atm(ji,jj) * 1E-6 )**2 zfugcoeff = EXP( patm(ji,jj) * (chemc(ji,jj,2) + 2.0 * zxc2 * chemc(ji,jj,3) ) & & / ( 82.05736 * ztkel )) zfco2 = zpco2atm(ji,jj) * zfugcoeff ! Compute CO2 flux for the sea and air zfld = zfco2 * chemc(ji,jj,1) * zkgco2(ji,jj) ! (mol/L) * (m/s) zflu = zh2co3(ji,jj) * zkgco2(ji,jj) ! (mol/L) (m/s) ? oce_co2(ji,jj) = ( zfld - zflu ) * rfact2 * e1e2t(ji,jj) * tmask(ji,jj,1) * 1000. ! compute the trend tra(ji,jj,1,jpdic) = tra(ji,jj,1,jpdic) + ( zfld - zflu ) * rfact2 / e3t_n(ji,jj,1) * tmask(ji,jj,1) ! Compute O2 flux zfld16 = patm(ji,jj) * chemo2(ji,jj,1) * zkgo2(ji,jj) ! (mol/L) * (m/s) zflu16 = trb(ji,jj,1,jpoxy) * zkgo2(ji,jj) zoflx(ji,jj) = ( zfld16 - zflu16 ) * tmask(ji,jj,1) tra(ji,jj,1,jpoxy) = tra(ji,jj,1,jpoxy) + zoflx(ji,jj) * rfact2 / e3t_n(ji,jj,1) END DO END DO t_oce_co2_flx = glob_sum( 'p4zflx', oce_co2(:,:) ) ! Total Flux of Carbon t_oce_co2_flx_cum = t_oce_co2_flx_cum + t_oce_co2_flx ! Cumulative Total Flux of Carbon ! t_atm_co2_flx = glob_sum( 'p4zflx', satmco2(:,:) * e1e2t(:,:) ) ! Total atmospheric pCO2 t_atm_co2_flx = atcco2 ! Total atmospheric pCO2 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 IF( lk_iomput .AND. knt == nrdttrc ) THEN ALLOCATE( zw2d(jpi,jpj) ) IF( iom_use( "Cflx" ) ) THEN zw2d(:,:) = oce_co2(:,:) / e1e2t(:,:) * rfact2r CALL iom_put( "Cflx" , zw2d ) ENDIF IF( iom_use( "Oflx" ) ) THEN zw2d(:,:) = zoflx(:,:) * 1000 * tmask(:,:,1) CALL iom_put( "Oflx" , zw2d ) ENDIF IF( iom_use( "Kg" ) ) THEN zw2d(:,:) = zkgco2(:,:) * tmask(:,:,1) CALL iom_put( "Kg" , zw2d ) ENDIF IF( iom_use( "Dpco2" ) ) THEN zw2d(:,:) = ( zpco2atm(:,:) - zh2co3(:,:) / ( chemc(:,:,1) + rtrn ) ) * tmask(:,:,1) CALL iom_put( "Dpco2" , zw2d ) ENDIF IF( iom_use( "Dpo2" ) ) THEN zw2d(:,:) = ( atcox * patm(:,:) - atcox * trb(:,:,1,jpoxy) / ( chemo2(:,:,1) + rtrn ) ) * tmask(:,:,1) CALL iom_put( "Dpo2" , zw2d ) ENDIF IF( iom_use( "tcflx" ) ) CALL iom_put( "tcflx" , t_oce_co2_flx * rfact2r ) ! molC/s CALL iom_put( "tcflxcum" , t_oce_co2_flx_cum ) ! molC ! DEALLOCATE( zw2d ) ENDIF ! IF( ln_timing ) CALL timing_stop('p4z_flx') ! END SUBROUTINE p4z_flx SUBROUTINE p4z_flx_init !!---------------------------------------------------------------------- !! *** ROUTINE p4z_flx_init *** !! !! ** Purpose : Initialization of atmospheric conditions !! !! ** Method : Read the nampisext namelist and check the parameters !! called at the first timestep (nittrc000) !! !! ** input : Namelist nampisext !!---------------------------------------------------------------------- INTEGER :: jm, ios ! Local integer !! NAMELIST/nampisext/ln_co2int, atcco2, clname, nn_offset !!---------------------------------------------------------------------- IF(lwp) THEN WRITE(numout,*) WRITE(numout,*) ' p4z_flx_init : atmospheric conditions for air-sea flux calculation' WRITE(numout,*) ' ~~~~~~~~~~~~' ENDIF ! REWIND( numnatp_ref ) ! Namelist nampisext in reference namelist : Pisces atm. conditions READ ( numnatp_ref, nampisext, IOSTAT = ios, ERR = 901) 901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nampisext in reference namelist', lwp ) REWIND( numnatp_cfg ) ! Namelist nampisext in configuration namelist : Pisces atm. conditions READ ( numnatp_cfg, nampisext, IOSTAT = ios, ERR = 902 ) 902 IF( ios > 0 ) CALL ctl_nam ( ios , 'nampisext in configuration namelist', lwp ) IF(lwm) WRITE ( numonp, nampisext ) ! IF(lwp) THEN ! control print WRITE(numout,*) ' Namelist : nampisext --- parameters for air-sea exchange' WRITE(numout,*) ' reading in the atm pCO2 file or constant value ln_co2int =', ln_co2int ENDIF ! CALL p4z_patm( nit000 ) ! IF( .NOT.ln_co2int .AND. .NOT.ln_presatmco2 ) THEN IF(lwp) THEN ! control print WRITE(numout,*) ' Constant Atmospheric pCO2 value atcco2 =', atcco2 ENDIF satmco2(:,:) = atcco2 ! Initialisation of atmospheric pco2 ELSEIF( ln_co2int .AND. .NOT.ln_presatmco2 ) THEN IF(lwp) THEN WRITE(numout,*) ' Constant Atmospheric pCO2 value atcco2 =', atcco2 WRITE(numout,*) ' Atmospheric pCO2 value from file clname =', TRIM( clname ) WRITE(numout,*) ' Offset model-data start year nn_offset =', nn_offset ENDIF CALL ctl_opn( numco2, TRIM( clname) , 'OLD', 'FORMATTED', 'SEQUENTIAL', -1 , numout, lwp ) jm = 0 ! Count the number of record in co2 file DO READ(numco2,*,END=100) jm = jm + 1 END DO 100 nmaxrec = jm - 1 ALLOCATE( years (nmaxrec) ) ; years (:) = 0._wp ALLOCATE( atcco2h(nmaxrec) ) ; atcco2h(:) = 0._wp ! REWIND(numco2) DO jm = 1, nmaxrec ! get xCO2 data READ(numco2, *) years(jm), atcco2h(jm) IF(lwp) WRITE(numout, '(f6.0,f7.2)') years(jm), atcco2h(jm) END DO CLOSE(numco2) ELSEIF( .NOT.ln_co2int .AND. ln_presatmco2 ) THEN IF(lwp) WRITE(numout,*) ' Spatialized Atmospheric pCO2 from an external file' ELSE IF(lwp) WRITE(numout,*) ' Spatialized Atmospheric pCO2 from an external file' ENDIF ! oce_co2(:,:) = 0._wp ! Initialization of Flux of Carbon t_oce_co2_flx = 0._wp t_atm_co2_flx = 0._wp ! END SUBROUTINE p4z_flx_init SUBROUTINE p4z_patm( kt ) !!---------------------------------------------------------------------- !! *** ROUTINE p4z_atm *** !! !! ** Purpose : Read and interpolate the external atmospheric sea-level pressure !! ** Method : Read the files and interpolate the appropriate variables !! !!---------------------------------------------------------------------- INTEGER, INTENT(in) :: kt ! ocean time step ! INTEGER :: ierr, ios ! Local integer CHARACTER(len=100) :: cn_dir ! Root directory for location of ssr files TYPE(FLD_N) :: sn_patm ! informations about the fields to be read TYPE(FLD_N) :: sn_atmco2 ! informations about the fields to be read !! NAMELIST/nampisatm/ ln_presatm, ln_presatmco2, sn_patm, sn_atmco2, cn_dir !!---------------------------------------------------------------------- ! IF( kt == nit000 ) THEN !== First call kt=nittrc000 ==! ! IF(lwp) THEN WRITE(numout,*) WRITE(numout,*) ' p4z_patm : sea-level atmospheric pressure' WRITE(numout,*) ' ~~~~~~~~' ENDIF ! REWIND( numnatp_ref ) ! Namelist nampisatm in reference namelist : Pisces atm. sea level pressure file READ ( numnatp_ref, nampisatm, IOSTAT = ios, ERR = 901) 901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nampisatm in reference namelist', lwp ) REWIND( numnatp_cfg ) ! Namelist nampisatm in configuration namelist : Pisces atm. sea level pressure file READ ( numnatp_cfg, nampisatm, IOSTAT = ios, ERR = 902 ) 902 IF( ios > 0 ) CALL ctl_nam ( ios , 'nampisatm in configuration namelist', lwp ) IF(lwm) WRITE ( numonp, nampisatm ) ! ! IF(lwp) THEN !* control print WRITE(numout,*) ' Namelist : nampisatm --- Atmospheric Pressure as external forcing' WRITE(numout,*) ' constant atmopsheric pressure (F) or from a file (T) ln_presatm = ', ln_presatm WRITE(numout,*) ' spatial atmopsheric CO2 for flux calcs ln_presatmco2 = ', ln_presatmco2 ENDIF ! IF( ln_presatm ) THEN ALLOCATE( sf_patm(1), STAT=ierr ) !* allocate and fill sf_patm (forcing structure) with sn_patm IF( ierr > 0 ) CALL ctl_stop( 'STOP', 'p4z_flx: unable to allocate sf_patm structure' ) ! CALL fld_fill( sf_patm, (/ sn_patm /), cn_dir, 'p4z_flx', 'Atmospheric pressure ', 'nampisatm' ) ALLOCATE( sf_patm(1)%fnow(jpi,jpj,1) ) IF( sn_patm%ln_tint ) ALLOCATE( sf_patm(1)%fdta(jpi,jpj,1,2) ) ENDIF ! IF( ln_presatmco2 ) THEN ALLOCATE( sf_atmco2(1), STAT=ierr ) !* allocate and fill sf_atmco2 (forcing structure) with sn_atmco2 IF( ierr > 0 ) CALL ctl_stop( 'STOP', 'p4z_flx: unable to allocate sf_atmco2 structure' ) ! CALL fld_fill( sf_atmco2, (/ sn_atmco2 /), cn_dir, 'p4z_flx', 'Atmospheric co2 partial pressure ', 'nampisatm' ) ALLOCATE( sf_atmco2(1)%fnow(jpi,jpj,1) ) IF( sn_atmco2%ln_tint ) ALLOCATE( sf_atmco2(1)%fdta(jpi,jpj,1,2) ) ENDIF ! IF( .NOT.ln_presatm ) patm(:,:) = 1._wp ! Initialize patm if no reading from a file ! ENDIF ! IF( ln_presatm ) THEN CALL fld_read( kt, 1, sf_patm ) !* input Patm provided at kt + 1/2 patm(:,:) = sf_patm(1)%fnow(:,:,1) ! atmospheric pressure ENDIF ! IF( ln_presatmco2 ) THEN CALL fld_read( kt, 1, sf_atmco2 ) !* input atmco2 provided at kt + 1/2 satmco2(:,:) = sf_atmco2(1)%fnow(:,:,1) ! atmospheric pressure ELSE satmco2(:,:) = atcco2 ! Initialize atmco2 if no reading from a file ENDIF ! END SUBROUTINE p4z_patm INTEGER FUNCTION p4z_flx_alloc() !!---------------------------------------------------------------------- !! *** ROUTINE p4z_flx_alloc *** !!---------------------------------------------------------------------- ALLOCATE( satmco2(jpi,jpj), patm(jpi,jpj), STAT=p4z_flx_alloc ) ! IF( p4z_flx_alloc /= 0 ) CALL ctl_warn('p4z_flx_alloc : failed to allocate arrays') ! END FUNCTION p4z_flx_alloc !!====================================================================== END MODULE p4zflx