C $Header: /u/gcmpack/MITgcm/pkg/bling/bling_dvm.F,v 1.6 2016/11/16 16:41:50 mmazloff Exp $ C $Name: $ #include "BLING_OPTIONS.h" CBOP subroutine BLING_DVM( I N_dvm,P_dvm,Fe_dvm, I PTR_O2, mld, O N_remindvm, P_remindvm, Fe_remindvm, I bi, bj, imin, imax, jmin, jmax, I myIter, myTime, myThid ) C ================================================================= C | subroutine bling_dvm C | o Diel Vertical Migration 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 N_dvm :: vertical transport of nitrogen by DVM C P_dvm :: vertical transport of phosphorus by DVM C Fe_dvm :: vertical transport of iron by DVM C PTR_O2 :: nitrate concentration C mld :: mixed layer depth _RL N_dvm (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) _RL P_dvm (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) _RL Fe_dvm(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) _RL PTR_O2(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) _RL mld (1-OLx:sNx+OLx,1-OLy:sNy+OLy) C === Output === C N_remindvm :: nitrogen remineralization due to diel vertical migration C P_remindvm :: phosphorus remineralization due to diel vertical migration C Fe_remindvm :: iron remineralization due to diel vertical migration _RL N_remindvm (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) _RL P_remindvm (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) _RL Fe_remindvm (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 tmp _RL depth_l _RL o2_upper _RL o2_lower _RL dz_upper _RL dz_lower _RL temp_upper _RL temp_lower _RL z_dvm_regr _RL frac_migr _RL fdvm_migr _RL fdvm_stat _RL fdvmn_vint _RL fdvmp_vint _RL fdvmfe_vint _RL z_dvm _RL dvm(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) _RL Fe_burial(1-OLx:sNx+OLx,1-OLy:sNy+OLy) _RL x_erfcc,z_erfcc,t_erfcc,erfcc CEOP c --------------------------------------------------------------------- c Initialize output and diagnostics DO k=1,Nr DO j=jmin,jmax DO i=imin,imax N_remindvm(i,j,k) = 0. _d 0 P_remindvm(i,j,k) = 0. _d 0 Fe_remindvm(i,j,k) = 0. _d 0 dvm(i,j,k) = 0. _d 0 ENDDO Fe_burial(i,j) = 0. _d 0 ENDDO ENDDO C --------------------------------------------------------------------- c DIEL VERTICAL MIGRATOR EXPORT c The effect of vertically-migrating animals on the export flux of organic c matter from the ocean surface is treated similarly to the scheme of c Bianchi et al., Nature Geoscience 2013. c This involves calculating the stationary depth of vertical migrators, using c an empirical multivariate regression, and ensuring that this remains c above the bottom as well as any suboxic waters. c The total DVM export flux is partitioned between a swimming migratory c component and the stationary component, and these are summed. C$TAF LOOP = parallel DO j=jmin,jmax C$TAF LOOP = parallel DO i=imin,imax c Initialize o2_upper = 0. o2_lower = 0. dz_upper = 0. dz_lower = 0. temp_upper = 0. temp_lower = 0. z_dvm_regr = 0. z_dvm = 0. frac_migr = 0. fdvm_migr = 0. fdvm_stat = 0. fdvmn_vint = 0. fdvmp_vint = 0. fdvmfe_vint = 0. DO k=1,Nr IF ( hFacC(i,j,k,bi,bj).gt.0. _d 0 ) THEN c Calculate the depth of migration based on linear regression. depth_l=-rF(k+1) c Average temperature and oxygen over upper 35 m, and 140-515m. c Also convert O2 to mmol m-3. if ( abs(depth_l) .lt. 35.) then dz_upper = dz_upper + drf(k) temp_upper = temp_upper + theta(i,j,k,bi,bj)*drf(k) o2_upper = o2_upper + PTR_O2(i,j,k) * drf(k)*1.0 _d 3 endif if ( (abs(depth_l) .gt. 140.0 _d 0) .and. & (abs(depth_l) .lt. 515. _d 0)) then dz_lower = dz_lower + drf(k) temp_lower = temp_lower + theta(i,j,k,bi,bj)*drf(k) o2_lower = o2_lower + PTR_O2(i,j,k) * drf(k)*1.0 _d 3 endif ENDIF ENDDO o2_upper = o2_upper / (epsln + dz_upper) temp_upper = temp_upper / (epsln + dz_upper) o2_lower = o2_lower / (epsln + dz_lower) temp_lower = temp_lower / (epsln + dz_lower) c Calculate the regression, using the constants given in Bianchi et al. (2013). c The variable values are bounded to lie within reasonable ranges: c O2 gradient : [-10,300] mmol/m3 c Log10 Chl : [-1.8,0.85] log10(mg/m3) c mld : [0,500] m c T gradient : [-3,20] C c!! replacing hblt_depth(i,j) with mld... #ifdef BLING_ADJOINT_SAFE z_dvm = 300. _d 0 #else z_dvm_regr = 398. _d 0 & - 0.56 _d 0*min(300. _d 0,max(-10. _d 0,(o2_upper - o2_lower))) & - 115. _d 0*min(0.85 _d 0,max(-1.80 _d 0, & log10(max(chl(i,j,1,bi,bj),chl_min)))) & + 0.36 _d 0*min(500. _d 0,max(epsln,mld(i,j))) & - 2.40 _d 0*min(20. _d 0,max(-3. _d 0,(temp_upper-temp_lower))) c Limit the depth of migration in polar winter. c Use irr_mem since this is averaged over multiple days, dampening the c diurnal cycle. c Tapers Z_DVM to the minimum when surface irradince is below a given c threshold (here 10 W/m2). if ( irr_mem(i,j,1,bi,bj) .lt. 10. ) then z_dvm_regr = 150. _d 0 + (z_dvm_regr - 150. _d 0) * & irr_mem(i,j,1,bi,bj) / 10. _d 0 endif c Check for suboxic water within the column. If found, set dvm c stationary depth to 2 layers above it. This is not meant to c represent a cessation of downward migration, but rather the c requirement for aerobic DVM respiration to occur above the suboxic c water, where O2 is available. tmp = 0 DO k=1,Nr-2 IF ( (hFacC(i,j,k,bi,bj).gt.0. _d 0) .and. (tmp.eq.0)) THEN z_dvm = -rf(k+1) if (PTR_O2(i,j,k+2) .lt. (5. _d 0*oxic_min)) tmp = 1 ENDIF enddo c The stationary depth is constrained between 150 and 700, above any c anoxic waters found, and above the bottom. z_dvm = min(700. _d 0,max(150. _d 0,z_dvm_regr),z_dvm,-rf(k+1)) c!! bling%zbot(i,j,grid_kmt(i,j))) * grid_tmask(i,j,1) c!! what is grid_kmt? #endif c Calculate the fraction of migratory respiration that occurs c during upwards and downwards swimming. The remainder is c respired near the stationary depth. c Constants for swimming speed and resting time are hard-coded c after Bianchi et al, Nature Geoscience 2013. frac_migr = max( 0.0 _d 0, min( 1.0 _d 0, (2.0 _d 0 * z_dvm) / & (epsln + 0.05 _d 0 * 0.5 _d 0 * 86400. _d 0))) c Calculate the vertical profile shapes of DVM fluxes. c These are given as the downward organic flux due to migratory c DVM remineralization, defined at the bottom of each layer k. tmp = 0 DO k=1,Nr IF ( (hFacC(i,j,k,bi,bj).gt.0. _d 0) .and. (tmp.eq.0)) THEN ! First, calculate the part due to active migration above ! the stationary depth. if (-rf(k+1) .lt. z_dvm) then fdvm_migr = frac_migr / (epsln + z_dvm - (-rf(2))) * & (z_dvm - (-rf(k+1)) ) else fdvm_migr = 0.0 endif c Then, calculate the part at the stationary depth. c Approximation of the complementary error function c From Numerical Recipes (F90, Ch. 6, p. 216) c Returns the complementary error function erfc(x) c with fractional error everywhere less than 1.2e-7 x_erfcc = (-rf(k) - z_dvm) / & ( (epsln + 2. _d 0 * sigma_dvm**2. _d 0)**0.5) z_erfcc = abs(x_erfcc) t_erfcc = 1. _d 0/(1. _d 0+0.5 _d 0*z_erfcc) erfcc = t_erfcc*exp(-z_erfcc*z_erfcc-1.26551223+t_erfcc* & (1.00002368+t_erfcc*(0.37409196+t_erfcc* & (.09678418+t_erfcc*(-.18628806+t_erfcc*(.27886807+ & t_erfcc*(-1.13520398+t_erfcc*(1.48851587+ & t_erfcc*(-0.82215223+t_erfcc*0.17087277))))))))) if (x_erfcc .lt. 0.0) then erfcc = 2.0 - erfcc endif fdvm_stat = (1. _d 0 - frac_migr) / 2. _d 0 * erfcc c Add the shapes, resulting in the 3-d DVM flux operator. If the c current layer is the bottom layer, or the layer beneath the c underlying layer is suboxic, all fluxes at and below the current c layer remain at the initialized value of zero. This will cause all c remaining DVM remineralization to occur in this layer. IF (k.LT.NR-1) THEN if (PTR_O2(i,j,k+2) .lt. (5. _d 0*oxic_min)) tmp = 1 ENDIF c!! if (k .eq. grid_kmt(i,j)) exit dvm(i,j,k) = fdvm_migr + fdvm_stat ENDIF enddo c Sum up the total organic flux to be transported by DVM do k = 1, nr fdvmn_vint = fdvmn_vint + N_dvm(i,j,k) * drf(k) fdvmp_vint = fdvmp_vint + P_dvm(i,j,k) * drf(k) fdvmfe_vint = fdvmfe_vint + Fe_dvm(i,j,k) * drf(k) enddo c Calculate the remineralization terms as the divergence of the flux N_remindvm(i,j,1) = fdvmn_vint * (1 - dvm(i,j,1)) / & (epsln + drf(1)) P_remindvm(i,j,1) = fdvmp_vint * (1 - dvm(i,j,1)) / & (epsln + drf(1)) Fe_remindvm(i,j,1) = fdvmfe_vint * (1 - dvm(i,j,1)) / & (epsln + drf(1)) do k = 2, nr N_remindvm(i,j,k) = fdvmn_vint * & (dvm(i,j,k-1) - dvm(i,j,k)) / (epsln + drf(k)) P_remindvm(i,j,k) = fdvmp_vint * & (dvm(i,j,k-1) - dvm(i,j,k)) / (epsln + drf(k)) Fe_remindvm(i,j,k) = fdvmfe_vint * & (dvm(i,j,k-1) - dvm(i,j,k)) / (epsln + drf(k)) enddo enddo enddo #endif /* ALLOW_BLING */ RETURN END