C $Header: /u/gcmpack/MITgcm/pkg/bling/bling_remineralization.F,v 1.11 2017/05/24 17:21:15 mmazloff Exp $
C $Name: $
#include "BLING_OPTIONS.h"
CBOP
subroutine BLING_REMIN(
I PTR_NO3, PTR_FE, PTR_O2, irr_inst,
I N_spm, P_spm, Fe_spm, CaCO3_uptake,
O N_reminp, P_reminp, Fe_reminsum,
O N_den_benthic, CaCO3_diss,
I bi, bj, imin, imax, jmin, jmax,
I myIter, myTime, myThid )
C =================================================================
C | subroutine bling_remin
C | o Organic matter export and remineralization.
C | - Sinking particulate flux and diel migration contribute to
C | export.
C | - Benthic denitrification
C | - Iron source from sediments
C | - Iron scavenging
C =================================================================
implicit none
C === Global variables ===
#include "SIZE.h"
#include "DYNVARS.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "GRID.h"
#include "BLING_VARS.h"
#include "PTRACERS_SIZE.h"
#include "PTRACERS_PARAMS.h"
#ifdef ALLOW_AUTODIFF
# include "tamc.h"
#endif
C === Routine arguments ===
C bi,bj :: tile indices
C iMin,iMax :: computation domain: 1rst index range
C jMin,jMax :: computation domain: 2nd index range
C myTime :: current time
C myIter :: current timestep
C myThid :: thread Id. number
INTEGER bi, bj, imin, imax, jmin, jmax
_RL myTime
INTEGER myIter
INTEGER myThid
C === Input ===
C PTR_NO3 :: nitrate concentration
C PTR_FE :: iron concentration
C PTR_O2 :: oxygen concentration
_RL PTR_NO3(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL PTR_FE(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL PTR_O2(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL irr_inst(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL N_spm(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL P_spm(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL Fe_spm(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL CaCO3_uptake(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
C === Output ===
C N_reminp :: remineralization of particulate organic nitrogen
C N_den_benthic :: Benthic denitrification
C P_reminp :: remineralization of particulate organic nitrogen
C Fe_reminsum :: iron remineralization and adsorption
C CaCO3_diss :: Calcium carbonate dissolution
_RL N_reminp(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL N_den_benthic(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL P_reminp(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL Fe_reminsum(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL CaCO3_diss(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
#ifdef ALLOW_BLING
C === Local variables ===
C i,j,k :: loop indices
INTEGER i,j,k
INTEGER bttmlyr
_RL PONflux_u
_RL PONflux_l
_RL POPflux_u
_RL POPflux_l
_RL PFEflux_u
_RL PFEflux_l
_RL CaCO3flux_u
_RL CaCO3flux_l
_RL depth_l
_RL zremin
_RL zremin_caco3
_RL wsink
_RL POC_sed
_RL Fe_sed(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL NO3_sed(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RL PO4_sed(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RL O2_sed(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RL lig_stability
_RL FreeFe
_RL Fe_ads_inorg(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL Fe_ads_org(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL log_btm_flx
_RL Fe_reminp(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL Fe_burial(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
CEOP
C ---------------------------------------------------------------------
C Initialize output and diagnostics
DO k=1,Nr
DO j=jmin,jmax
DO i=imin,imax
Fe_ads_org(i,j,k) = 0. _d 0
Fe_ads_inorg(i,j,k) = 0. _d 0
N_reminp(i,j,k) = 0. _d 0
P_reminp(i,j,k) = 0. _d 0
Fe_reminp(i,j,k) = 0. _d 0
Fe_reminsum(i,j,k) = 0. _d 0
N_den_benthic(i,j,k)= 0. _d 0
CaCO3_diss(i,j,k) = 0. _d 0
ENDDO
ENDDO
ENDDO
DO j=jmin,jmax
DO i=imin,imax
Fe_burial(i,j) = 0. _d 0
NO3_sed(i,j) = 0. _d 0
PO4_sed(i,j) = 0. _d 0
O2_sed(i,j) = 0. _d 0
ENDDO
ENDDO
C ---------------------------------------------------------------------
C Remineralization
C$TAF LOOP = parallel
DO j=jmin,jmax
C$TAF LOOP = parallel
DO i=imin,imax
C Initialize upper flux
PONflux_u = 0. _d 0
POPflux_u = 0. _d 0
PFEflux_u = 0. _d 0
CaCO3flux_u = 0. _d 0
DO k=1,Nr
C Initialization here helps taf
Fe_ads_org(i,j,k) = 0. _d 0
C ARE WE ON THE BOTTOM
bttmlyr = 1
IF (k.LT.Nr) THEN
IF (hFacC(i,j,k+1,bi,bj).GT.0) bttmlyr = 0
C we are not yet at the bottom
ENDIF
IF ( hFacC(i,j,k,bi,bj).gt.0. _d 0 ) THEN
C Sinking speed is evaluated at the bottom of the cell
depth_l=-rF(k+1)
IF (depth_l .LE. wsink0z) THEN
wsink = wsink0_2d(i,j,bi,bj)
ELSE
wsink = wsinkacc * (depth_l - wsink0z) + wsink0_2d(i,j,bi,bj)
ENDIF
C Nutrient remineralization lengthscale
C Not an e-folding scale: this term increases with remineralization.
zremin = gamma_POM2d(i,j,bi,bj) * ( PTR_O2(i,j,k)**2 /
& (k_O2**2 + PTR_O2(i,j,k)**2) * (1-remin_min)
& + remin_min )/(wsink + epsln)
C Calcium remineralization relaxed toward the inverse of the
C ca_remin_depth constant value as the calcite saturation approaches 0.
zremin_caco3 = 1. _d 0/ca_remin_depth*(1. _d 0 - min(1. _d 0,
& omegaC(i,j,k,bi,bj) + epsln ))
C POM flux leaving the cell
PONflux_l = (PONflux_u+N_spm(i,j,k)*drF(k)
& *hFacC(i,j,k,bi,bj))/(1+zremin*drF(k)
& *hFacC(i,j,k,bi,bj))
POPflux_l = (POPflux_u+P_spm(i,j,k)*drF(k)
& *hFacC(i,j,k,bi,bj))/(1+zremin*drF(k)
& *hFacC(i,j,k,bi,bj))
C CaCO3 flux leaving the cell
CaCO3flux_l = (caco3flux_u+CaCO3_uptake(i,j,k)*drF(k)
& *hFacC(i,j,k,bi,bj))/(1+zremin_caco3*drF(k)
& *hFacC(i,j,k,bi,bj))
C Start with cells that are not the deepest cells
IF (bttmlyr.EQ.0) THEN
C Nutrient accumulation in a cell is given by the biological production
C (and instant remineralization) of particulate organic matter
C plus flux thought upper interface minus flux through lower interface.
C (Since not deepest cell: hFacC=1)
N_reminp(i,j,k) = (PONflux_u + N_spm(i,j,k)*drF(k)
& - PONflux_l)*recip_drF(k)
P_reminp(i,j,k) = (POPflux_u + P_spm(i,j,k)*drF(k)
& - POPflux_l)*recip_drF(k)
CaCO3_diss(i,j,k) = (CaCO3flux_u + CaCO3_uptake(i,j,k)
& *drF(k) - CaCO3flux_l)*recip_drF(k)
Fe_sed(i,j,k) = 0. _d 0
C NOW DO BOTTOM LAYER
ELSE
C If this layer is adjacent to bottom topography or it is the deepest
C cell of the domain, then remineralize/dissolve in this grid cell
C i.e. do not subtract off lower boundary fluxes when calculating remin
N_reminp(i,j,k) = PONflux_u*recip_drF(k)
& *recip_hFacC(i,j,k,bi,bj) + N_spm(i,j,k)
P_reminp(i,j,k) = POPflux_u*recip_drF(k)
& *recip_hFacC(i,j,k,bi,bj) + P_spm(i,j,k)
CaCO3_diss(i,j,k) = CaCO3flux_u*recip_drF(k)
& *recip_hFacC(i,j,k,bi,bj) + CaCO3_uptake(i,j,k)
C Efflux Fed out of sediments
C The phosphate flux hitting the bottom boundary
C is used to scale the return of iron to the water column.
C Maximum value added for numerical stability.
POC_sed = PONflux_l * CtoN
Fe_sed(i,j,k) = max(epsln, FetoC_sed * POC_sed * recip_drF(k)
& *recip_hFacC(i,j,k,bi,bj))
cav log_btm_flx = 0. _d 0
log_btm_flx = 1. _d -20
CMM: this is causing instability in the adjoint. Needs debugging
#ifndef BLING_ADJOINT_SAFE
IF (POC_sed .gt. 0. _d 0) THEN
C Convert from mol N m-2 s-1 to umol C cm-2 d-1 and take the log
log_btm_flx = log10(min(43.0 _d 0, POC_sed *
& 86400. _d 0 * 100.0 _d 0))
C Metamodel gives units of umol C cm-2 d-1, convert to mol N m-2 s-1 and
C multiply by no3_2_n to give NO3 consumption rate
N_den_benthic(i,j,k) = min (POC_sed * NO3toN / CtoN,
& (10 _d 0)**(-0.9543 _d 0 + 0.7662 _d 0 *
& log_btm_flx - 0.235 _d 0 * log_btm_flx * log_btm_flx)
& / (CtoN * 86400. _d 0 * 100.0 _d 0) * NO3toN *
& PTR_NO3(i,j,k) / (k_no3 + PTR_NO3(i,j,k)) ) *
& recip_drF(k)
ENDIF
#endif
C ---------------------------------------------------------------------
C Calculate external bottom fluxes for tracer_vertdiff. Positive fluxes
C are into the water column from the seafloor. For P, the bottom flux puts
C the sinking flux reaching the bottom cell into the water column through
C diffusion. For iron, the sinking flux disappears into the sediments if
C bottom waters are oxic (assumed adsorbed as oxides). If bottom waters are
C anoxic, the sinking flux of Fe is returned to the water column.
C
C For oxygen, the consumption of oxidant required to respire the settling flux
C of organic matter (in support of the no3 bottom flux) diffuses from the
C bottom water into the sediment.
C Assume all NO3 for benthic denitrification is supplied from the bottom water,
C and that all organic N is also consumed under denitrification (Complete
C Denitrification, sensu Paulmier, Biogeosciences 2009). Therefore, no NO3 is
C regenerated from organic matter respired by benthic denitrification
C (necessitating the second term in b_no3).
NO3_sed(i,j) = PONflux_l*drF(k)*hFacC(i,j,k,bi,bj)
& - N_den_benthic(i,j,k) / NO3toN
PO4_sed(i,j) = POPflux_l*drF(k)*hFacC(i,j,k,bi,bj)
C Oxygen flux into sediments is that required to support non-denitrification
C respiration, assuming a 4/5 oxidant ratio of O2 to NO3. Oxygen consumption
C is allowed to continue at negative oxygen concentrations, representing
C sulphate reduction.
O2_sed(i,j) = -(O2toN * PONflux_l*drF(k)*hFacC(i,j,k,bi,bj)
& - N_den_benthic(i,j,k)* 1.25)
ENDIF
C Begin iron uptake calculations by determining ligand bound and free iron.
C Both forms are available for biology, but only free iron is scavenged
C onto particles and forms colloids.
lig_stability = kFe_eq_lig_max-(KFe_eq_lig_max-kFe_eq_lig_min)
& *(irr_inst(i,j,k)**2
& /(kFe_eq_lig_irr**2+irr_inst(i,j,k)**2))
& *max(epsln,min(1. _d 0,(PTR_FE(i,j,k)
& -kFe_eq_lig_Femin)/
& (PTR_FE(i,j,k)+epsln)*1.2 _d 0))
C Use the quadratic equation to solve for binding between iron and ligands
FreeFe = (-(1+lig_stability*(ligand-PTR_FE(i,j,k)))
& +((1+lig_stability*(ligand-PTR_FE(i,j,k)))**2+4*
& lig_stability*PTR_FE(i,j,k))**(0.5))/(2*
& lig_stability)
C Iron scavenging does not occur in anoxic water (Fe2+ is soluble), so set
C FreeFe = 0 when anoxic. FreeFe should be interpreted the free iron that
C participates in scavenging.
IF (PTR_O2(i,j,k) .LT. oxic_min) THEN
FreeFe = 0. _d 0
ENDIF
C Two mechanisms for iron uptake, in addition to biological production:
C colloidal scavenging and scavenging by organic matter.
Fe_ads_inorg(i,j,k) =
& kFe_inorg*(max(1. _d -8,FreeFe))**(1.5)
C Scavenging of iron by organic matter:
C The POM value used is the bottom boundary flux. This does not occur in
C oxic waters, but FreeFe is set to 0 in such waters earlier.
IF ( PONflux_l .GT. 0. _d 0 ) THEN
Fe_ads_org(i,j,k) =
& kFE_org*(PONflux_l/(epsln + wsink)
& * MasstoN)**(0.58)*FreeFe
ENDIF
C If water is oxic then the iron is remineralized normally. Otherwise
C it is completely remineralized (fe 2+ is soluble, but unstable
C in oxidizing environments).
PFEflux_l = (PFEflux_u+(Fe_spm(i,j,k)+Fe_ads_inorg(i,j,k)
& +Fe_ads_org(i,j,k))*drF(k)
& *hFacC(i,j,k,bi,bj))/(1+zremin*drF(k)
& *hFacC(i,j,k,bi,bj))
C Added the burial flux of sinking particulate iron here as a
C diagnostic, needed to calculate mass balance of iron.
C this is calculated last for the deepest cell
Fe_burial(i,j) = PFEflux_l
IF ( PTR_O2(i,j,k) .LT. oxic_min ) THEN
PFEflux_l = 0. _d 0
ENDIF
Fe_reminp(i,j,k) = (PFEflux_u+(Fe_spm(i,j,k)
& +Fe_ads_inorg(i,j,k)
& +Fe_ads_org(i,j,k))*drF(k)
& *hFacC(i,j,k,bi,bj)-PFEflux_l)*recip_drF(k)
& *recip_hFacC(i,j,k,bi,bj)
C Prepare the tracers for the next layer down
PONflux_u = PONflux_l
POPflux_u = POPflux_l
PFEflux_u = PFEflux_l
CaCO3flux_u = CaCO3flux_l
Fe_reminsum(i,j,k) = Fe_reminp(i,j,k) + Fe_sed(i,j,k)
& - Fe_ads_org(i,j,k) - Fe_ads_inorg(i,j,k)
ENDIF
ENDDO
ENDDO
ENDDO
c ---------------------------------------------------------------------
#ifdef ALLOW_DIAGNOSTICS
IF ( useDiagnostics ) THEN
c 3d local variables
CALL DIAGNOSTICS_FILL(Fe_ads_org, 'BLGFEADO',0,Nr,2,bi,bj,
& myThid)
CALL DIAGNOSTICS_FILL(Fe_ads_inorg, 'BLGFEADI',0,Nr,2,bi,bj,
& myThid)
CALL DIAGNOSTICS_FILL(Fe_sed, 'BLGFESED',0,Nr,2,bi,bj,myThid)
CALL DIAGNOSTICS_FILL(Fe_reminp,'BLGFEREM',0,Nr,2,bi,bj,myThid)
CALL DIAGNOSTICS_FILL(N_reminp, 'BLGNREM ',0,Nr,2,bi,bj,myThid)
CALL DIAGNOSTICS_FILL(P_reminp, 'BLGPREM ',0,Nr,2,bi,bj,myThid)
c 2d local variables
CALL DIAGNOSTICS_FILL(Fe_burial,'BLGFEBUR',0,1,2,bi,bj,myThid)
CALL DIAGNOSTICS_FILL(NO3_sed, 'BLGNSED ',0,1,2,bi,bj,myThid)
CALL DIAGNOSTICS_FILL(PO4_sed, 'BLGPSED ',0,1,2,bi,bj,myThid)
CALL DIAGNOSTICS_FILL(O2_sed, 'BLGO2SED',0,1,2,bi,bj,myThid)
ENDIF
#endif /* ALLOW_DIAGNOSTICS */
#endif /* ALLOW_BLING */
RETURN
END