MODULE sbcfwb !!====================================================================== !! *** MODULE sbcfwb *** !! Ocean fluxes : domain averaged freshwater budget !!====================================================================== !! History : OPA ! 2001-02 (E. Durand) Original code !! NEMO 1.0 ! 2002-06 (G. Madec) F90: Free form and module !! 3.0 ! 2006-08 (G. Madec) Surface module !! 3.2 ! 2009-07 (C. Talandier) emp mean s spread over erp area !! 3.6 ! 2014-11 (P. Mathiot ) add ice shelf melting !!---------------------------------------------------------------------- !!---------------------------------------------------------------------- !! sbc_fwb : freshwater budget for global ocean configurations !! in free surface and forced mode !!---------------------------------------------------------------------- USE oce ! ocean dynamics and tracers USE dom_oce ! ocean space and time domain USE sbc_oce ! surface ocean boundary condition USE phycst ! physical constants USE sbcrnf ! ocean runoffs USE sbcisf ! ice shelf melting contribution USE sbcssr ! SS damping terms USE in_out_manager ! I/O manager USE lib_mpp ! distribued memory computing library USE wrk_nemo ! work arrays USE timing ! Timing USE lbclnk ! ocean lateral boundary conditions USE lib_fortran IMPLICIT NONE PRIVATE PUBLIC sbc_fwb ! routine called by step REAL(wp) :: a_fwb_b ! annual domain averaged freshwater budget REAL(wp) :: a_fwb ! for 2 year before (_b) and before year. REAL(wp) :: fwfold ! fwfold to be suppressed REAL(wp) :: area ! global mean ocean surface (interior domain) !! * Substitutions # include "domzgr_substitute.h90" # include "vectopt_loop_substitute.h90" !!---------------------------------------------------------------------- !! NEMO/OPA 3.3 , NEMO Consortium (2010) !! $Id: sbcfwb.F90 5628 2015-07-22 20:26:35Z mathiot $ !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) !!---------------------------------------------------------------------- CONTAINS SUBROUTINE sbc_fwb( kt, kn_fwb, kn_fsbc ) !!--------------------------------------------------------------------- !! *** ROUTINE sbc_fwb *** !! !! ** Purpose : Control the mean sea surface drift !! !! ** Method : several ways depending on kn_fwb !! =0 no control !! =1 global mean of emp set to zero at each nn_fsbc time step !! =2 annual global mean corrected from previous year !! =3 global mean of emp set to zero at each nn_fsbc time step !! & spread out over erp area depending its sign !! Note: if sea ice is embedded it is taken into account when computing the budget !!---------------------------------------------------------------------- INTEGER, INTENT( in ) :: kt ! ocean time-step index INTEGER, INTENT( in ) :: kn_fsbc ! INTEGER, INTENT( in ) :: kn_fwb ! ocean time-step index ! INTEGER :: inum, ikty, iyear ! local integers REAL(wp) :: z_fwf, z_fwf_nsrf, zsum_fwf, zsum_erp ! local scalars REAL(wp) :: zsurf_neg, zsurf_pos, zsurf_tospread, zcoef ! - - REAL(wp), POINTER, DIMENSION(:,:) :: ztmsk_neg, ztmsk_pos, z_wgt ! 2D workspaces REAL(wp), POINTER, DIMENSION(:,:) :: ztmsk_tospread, zerp_cor ! - - !!---------------------------------------------------------------------- ! IF( nn_timing == 1 ) CALL timing_start('sbc_fwb') ! CALL wrk_alloc( jpi,jpj, ztmsk_neg, ztmsk_pos, ztmsk_tospread, z_wgt, zerp_cor ) ! IF( kt == nit000 ) THEN IF(lwp) THEN WRITE(numout,*) WRITE(numout,*) 'sbc_fwb : FreshWater Budget correction' WRITE(numout,*) '~~~~~~~' IF( kn_fwb == 1 ) WRITE(numout,*) ' instantaneously set to zero' IF( kn_fwb == 2 ) WRITE(numout,*) ' adjusted from previous year budget' IF( kn_fwb == 3 ) WRITE(numout,*) ' fwf set to zero and spread out over erp area' ENDIF ! IF( kn_fwb == 3 .AND. nn_sssr /= 2 ) CALL ctl_stop( 'sbc_fwb: nn_fwb = 3 requires nn_sssr = 2, we stop ' ) IF( kn_fwb == 3 .AND. ln_isfcav ) CALL ctl_stop( 'sbc_fwb: nn_fwb = 3 with ln_isfcav = .TRUE. not working, we stop ' ) ! area = glob_sum( e1e2t(:,:) * tmask(:,:,1)) ! interior global domain surface ! isf cavities are excluded because it can feedback to the melting with generation of inhibition of plumes ! and in case of no melt, it can generate HSSW. ! #if ! defined key_lim2 && ! defined key_lim3 && ! defined key_cice snwice_mass_b(:,:) = 0.e0 ! no sea-ice model is being used : no snow+ice mass snwice_mass (:,:) = 0.e0 #endif ! ENDIF SELECT CASE ( kn_fwb ) ! CASE ( 1 ) !== global mean fwf set to zero ==! ! IF( MOD( kt-1, kn_fsbc ) == 0 ) THEN z_fwf = glob_sum( e1e2t(:,:) * ( emp(:,:) - rnf(:,:) + fwfisf(:,:) - snwice_fmass(:,:) ) ) / area ! sum over the global domain zcoef = z_fwf * rcp emp(:,:) = emp(:,:) - z_fwf * tmask(:,:,1) qns(:,:) = qns(:,:) + zcoef * sst_m(:,:) * tmask(:,:,1) ! account for change to the heat budget due to fw correction ENDIF ! CASE ( 2 ) !== fwf budget adjusted from the previous year ==! ! IF( kt == nit000 ) THEN ! initialisation ! ! Read the corrective factor on precipitations (fwfold) CALL ctl_opn( inum, 'EMPave_old.dat', 'OLD', 'FORMATTED', 'SEQUENTIAL', -1, numout, .FALSE. ) READ ( inum, "(24X,I8,2ES24.16)" ) iyear, a_fwb_b, a_fwb CLOSE( inum ) fwfold = a_fwb ! current year freshwater budget correction ! ! estimate from the previous year budget IF(lwp)WRITE(numout,*) IF(lwp)WRITE(numout,*)'sbc_fwb : year = ',iyear , ' freshwater budget correction = ', fwfold IF(lwp)WRITE(numout,*)' year = ',iyear-1, ' freshwater budget read = ', a_fwb IF(lwp)WRITE(numout,*)' year = ',iyear-2, ' freshwater budget read = ', a_fwb_b ENDIF ! ! Update fwfold if new year start ikty = 365 * 86400 / rdttra(1) !!bug use of 365 days leap year or 360d year !!!!!!! IF( MOD( kt, ikty ) == 0 ) THEN a_fwb_b = a_fwb ! mean sea level taking into account the ice+snow ! sum over the global domain a_fwb = glob_sum( e1e2t(:,:) * ( sshn(:,:) + snwice_mass(:,:) * r1_rau0 ) ) a_fwb = a_fwb * 1.e+3 / ( area * rday * 365. ) ! convert in Kg/m3/s = mm/s !!gm ! !!bug 365d year fwfold = a_fwb ! current year freshwater budget correction ! ! estimate from the previous year budget ENDIF ! IF( MOD( kt-1, kn_fsbc ) == 0 ) THEN ! correct the freshwater fluxes zcoef = fwfold * rcp emp(:,:) = emp(:,:) + fwfold * tmask(:,:,1) qns(:,:) = qns(:,:) - zcoef * sst_m(:,:) * tmask(:,:,1) ! account for change to the heat budget due to fw correction ENDIF ! IF( kt == nitend .AND. lwp ) THEN ! save fwfold value in a file CALL ctl_opn( inum, 'EMPave.dat', 'REPLACE', 'FORMATTED', 'SEQUENTIAL', -1, numout, .FALSE., narea ) WRITE( inum, "(24X,I8,2ES24.16)" ) nyear, a_fwb_b, a_fwb CLOSE( inum ) ENDIF ! CASE ( 3 ) !== global fwf set to zero and spread out over erp area ==! ! IF( MOD( kt-1, kn_fsbc ) == 0 ) THEN ztmsk_pos(:,:) = tmask_i(:,:) ! Select <0 and >0 area of erp WHERE( erp < 0._wp ) ztmsk_pos = 0._wp ztmsk_neg(:,:) = tmask_i(:,:) - ztmsk_pos(:,:) ! zsurf_neg = glob_sum( e1e2t(:,:)*ztmsk_neg(:,:) ) ! Area filled by <0 and >0 erp zsurf_pos = glob_sum( e1e2t(:,:)*ztmsk_pos(:,:) ) ! ! fwf global mean (excluding ocean to ice/snow exchanges) z_fwf = glob_sum( e1e2t(:,:) * ( emp(:,:) - rnf(:,:) + fwfisf(:,:) - snwice_fmass(:,:) ) ) / area ! IF( z_fwf < 0._wp ) THEN ! spread out over >0 erp area to increase evaporation zsurf_tospread = zsurf_pos ztmsk_tospread(:,:) = ztmsk_pos(:,:) ELSE ! spread out over <0 erp area to increase precipitation zsurf_tospread = zsurf_neg ztmsk_tospread(:,:) = ztmsk_neg(:,:) ENDIF ! zsum_fwf = glob_sum( e1e2t(:,:) * z_fwf ) ! fwf global mean over <0 or >0 erp area !!gm : zsum_fwf = z_fwf * area ??? it is right? I think so.... z_fwf_nsrf = zsum_fwf / ( zsurf_tospread + rsmall ) ! ! weight to respect erp field 2D structure zsum_erp = glob_sum( ztmsk_tospread(:,:) * erp(:,:) * e1e2t(:,:) ) z_wgt(:,:) = ztmsk_tospread(:,:) * erp(:,:) / ( zsum_erp + rsmall ) ! ! final correction term to apply zerp_cor(:,:) = -1. * z_fwf_nsrf * zsurf_tospread * z_wgt(:,:) ! !!gm ===>>>> lbc_lnk should be useless as all the computation is done over the whole domain ! CALL lbc_lnk( zerp_cor, 'T', 1. ) ! emp(:,:) = emp(:,:) + zerp_cor(:,:) qns(:,:) = qns(:,:) - zerp_cor(:,:) * rcp * sst_m(:,:) ! account for change to the heat budget due to fw correction erp(:,:) = erp(:,:) + zerp_cor(:,:) ! IF( nprint == 1 .AND. lwp ) THEN ! control print IF( z_fwf < 0._wp ) THEN WRITE(numout,*)' z_fwf < 0' WRITE(numout,*)' SUM(erp+) = ', SUM( ztmsk_tospread(:,:)*erp(:,:)*e1e2t(:,:) )*1.e-9,' Sv' ELSE WRITE(numout,*)' z_fwf >= 0' WRITE(numout,*)' SUM(erp-) = ', SUM( ztmsk_tospread(:,:)*erp(:,:)*e1e2t(:,:) )*1.e-9,' Sv' ENDIF WRITE(numout,*)' SUM(empG) = ', SUM( z_fwf*e1e2t(:,:) )*1.e-9,' Sv' WRITE(numout,*)' z_fwf = ', z_fwf ,' Kg/m2/s' WRITE(numout,*)' z_fwf_nsrf = ', z_fwf_nsrf ,' Kg/m2/s' WRITE(numout,*)' MIN(zerp_cor) = ', MINVAL(zerp_cor) WRITE(numout,*)' MAX(zerp_cor) = ', MAXVAL(zerp_cor) ENDIF ENDIF ! CASE DEFAULT !== you should never be there ==! CALL ctl_stop( 'sbc_fwb : wrong nn_fwb value for the FreshWater Budget correction, choose either 1, 2 or 3' ) ! END SELECT ! CALL wrk_dealloc( jpi,jpj, ztmsk_neg, ztmsk_pos, ztmsk_tospread, z_wgt, zerp_cor ) ! IF( nn_timing == 1 ) CALL timing_stop('sbc_fwb') ! END SUBROUTINE sbc_fwb !!====================================================================== END MODULE sbcfwb