module photolysis_online_mod implicit none contains !============================================================================== subroutine photolysis_online(nlayer, deutchem, nb_phot_max, $ alt, press, temp, mmean, $ i_co2, i_co, i_o, i_o1d, i_o2, i_o3, i_h, $ i_h2, i_oh, i_ho2, i_h2o2, i_h2o, $ i_n, i_n2d, i_no, i_no2, i_n2, nesp, rm, $ tau, sza, dist_sol, v_phot) use photolysis_mod implicit none ! input logical, intent(in) :: deutchem integer, intent(in) :: nesp ! total number of chemical species integer, intent(in) :: nlayer integer, intent(in) :: nb_phot_max integer, intent(in) :: i_co2, i_co, i_o, i_o1d, i_o2, i_o3, i_h, $ i_h2, i_oh, i_ho2, i_h2o2, i_h2o, $ i_n, i_n2d, i_no, i_no2, i_n2 real, dimension(nlayer), intent(in) :: press, temp, mmean ! pressure (hpa)/temperature (k)/mean molecular mass (g.mol-1) real, dimension(nlayer), intent(in) :: alt ! altitude (km) real, dimension(nlayer,nesp), intent(in) :: rm ! mixing ratios real, intent(in) :: tau ! integrated aerosol optical depth at the surface real, intent(in) :: sza ! solar zenith angle (degrees) real, intent(in) :: dist_sol ! solar distance (au) ! output real (kind = 8), dimension(nlayer,nb_phot_max) :: v_phot ! photolysis rates (s-1) ! solar flux at mars real, dimension(nw) :: fmars ! solar flux (w.m-2.nm-1) real :: factor ! cross-sections real, dimension(nlayer,nw,nphot) :: sj ! general cross-section array (cm2) ! atmosphere real, dimension(nlayer+1) :: zpress, zalt, ztemp, zmmean ! pressure (hpa)/altitude (km)/temperature (k)/mean molecular mass (g.mol-1) real, dimension(nlayer+1) :: colinc ! air column increment (molecule.cm-2) real, dimension(nlayer+1,nw) :: dtrl ! rayleigh optical depth real, dimension(nlayer+1,nw) :: dtaer ! aerosol optical depth real, dimension(nlayer+1,nw) :: omaer ! aerosol single scattering albedo real, dimension(nlayer+1,nw) :: gaer ! aerosol asymmetry parameter real, dimension(nlayer+1,nw) :: dtcld ! cloud optical depth real, dimension(nlayer+1,nw) :: omcld ! cloud single scattering albedo real, dimension(nlayer+1,nw) :: gcld ! cloud asymmetry parameter real, dimension(nlayer+1,nw,nabs) :: dtgas ! optical depth for each gas real, dimension(nlayer+1,nw) :: dagas ! total gas optical depth real, dimension(nlayer+1) :: edir, edn, eup ! normalised irradiances real, dimension(nlayer+1) :: fdir, fdn, fup ! normalised actinic fluxes real, dimension(nlayer+1) :: saflux ! total actinic flux integer, dimension(0:nlayer+1) :: nid real, dimension(0:nlayer+1,nlayer+1) :: dsdh integer :: j_o2_o, j_o2_o1d, j_co2_o, j_co2_o1d, j_o3_o1d, j_o3_o, $ j_h2o, j_h2o2, j_ho2, j_h2, j_no, j_no2, j_n2, $ j_hdo_od, j_hdo_d integer :: a_o2, a_co2, a_o3, a_h2o, a_h2o2, a_ho2, a_h2, a_no, $ a_no2, a_n2 integer :: nlev, i, ilay, ilev, iw, ialt real :: deltaj ! absorbing gas numbering a_o2 = 1 ! o2 a_co2 = 2 ! co2 a_o3 = 3 ! o3 a_h2o = 4 ! h2o a_h2o2 = 5 ! h2o2 a_ho2 = 6 ! ho2 a_h2 = 7 ! h2 a_no = 8 ! no a_no2 = 9 ! no2 a_n2 = 10 ! n2 ! photodissociation rates numbering. ! photodissociations must be ordered the same way in subroutine "indice" j_o2_o = 1 ! o2 + hv -> o + o j_o2_o1d = 2 ! o2 + hv -> o + o(1d) j_co2_o = 3 ! co2 + hv -> co + o j_co2_o1d = 4 ! co2 + hv -> co + o(1d) j_o3_o1d = 5 ! o3 + hv -> o2 + o(1d) j_o3_o = 6 ! o3 + hv -> o2 + o j_h2o = 7 ! h2o + hv -> h + oh j_h2o2 = 8 ! h2o2 + hv -> oh + oh j_ho2 = 9 ! ho2 + hv -> oh + o j_h2 = 10 ! h2 + hv -> h + h j_no = 11 ! no + hv -> n + o j_no2 = 12 ! no2 + hv -> no + o j_n2 = 13 ! n2 + hv -> n + n j_hdo_od = 14 ! hdo + hv -> od + h j_hdo_d = 15 ! hdo + hv -> d + oh !==== define working vertical grid for the uv radiative code nlev = nlayer + 1 do ilev = 1,nlev-1 zpress(ilev) = press(ilev) zalt(ilev) = alt(ilev) ztemp(ilev) = temp(ilev) zmmean(ilev) = mmean(ilev) end do zpress(nlev) = 0. ! top of the atmosphere zalt(nlev) = zalt(nlev-1) + (zalt(nlev-1) - zalt(nlev-2)) ztemp(nlev) = ztemp(nlev-1) zmmean(nlev) = zmmean(nlev-1) !==== air column increments and rayleigh optical depth call setair(nlev, nw, wl, wc, zpress, ztemp, zmmean, colinc, dtrl) !==== set temperature-dependent cross-sections and optical depths dtgas(:,:,:) = 0. ! o2: call seto2(nphot, nlayer, nw, wc, mopt, temp, xso2_150, xso2_200, $ xso2_250, xso2_300, yieldo2, j_o2_o, j_o2_o1d, $ colinc(1:nlayer), rm(:,i_o2), $ dtgas(1:nlayer,:,a_o2), sj) ! co2: call setco2(nphot, nlayer, nw, wc, temp, xsco2_195, xsco2_295, $ xsco2_370, yieldco2, j_co2_o, j_co2_o1d, $ colinc(1:nlayer), rm(:,i_co2), $ dtgas(1:nlayer,:,a_co2), sj) ! o3: call seto3(nphot, nlayer, nw, wc, temp, xso3_218, xso3_298, $ j_o3_o, j_o3_o1d, $ colinc(1:nlayer), rm(:,i_o3), $ dtgas(1:nlayer,:,a_o3), sj) ! h2o2: call seth2o2(nphot, nlayer, nw, wc, temp, xsh2o2, j_h2o2, $ colinc(1:nlayer), rm(:,i_h2o2), $ dtgas(1:nlayer,:,a_h2o2), sj) ! no2: call setno2(nphot, nlayer, nw, wc, temp, xsno2, xsno2_220, $ xsno2_294, yldno2_248, yldno2_298, j_no2, $ colinc(1:nlayer), rm(:,i_no2), $ dtgas(1:nlayer,:,a_no2), sj) !==== temperature-independent optical depths and cross-sections ! optical depths do ilay = 1,nlayer do iw = 1,nw-1 dtgas(ilay,iw,a_h2o) = colinc(ilay)*rm(ilay,i_h2o)*xsh2o(iw) dtgas(ilay,iw,a_ho2) = colinc(ilay)*rm(ilay,i_ho2)*xsho2(iw) dtgas(ilay,iw,a_h2) = colinc(ilay)*rm(ilay,i_h2)*xsh2(iw) dtgas(ilay,iw,a_no) = colinc(ilay)*rm(ilay,i_no)*xsno(iw) dtgas(ilay,iw,a_n2) = colinc(ilay)*rm(ilay,i_n2)*xsn2(iw) end do end do ! total gas optical depth dagas(:,:) = 0. do ilay = 1,nlayer do iw = 1,nw-1 do i = 1,nabs dagas(ilay,iw) = dagas(ilay,iw) + dtgas(ilay,iw,i) end do end do end do ! cross-sections do ilay = 1,nlayer do iw = 1,nw-1 sj(ilay,iw,j_h2o) = xsh2o(iw) ! h2o sj(ilay,iw,j_ho2) = xsho2(iw) ! ho2 sj(ilay,iw,j_h2) = xsh2(iw)*yieldh2(iw) ! h2 sj(ilay,iw,j_no) = xsno(iw)*yieldno(iw) ! no sj(ilay,iw,j_n2) = xsn2(iw)*yieldn2(iw) ! n2 end do end do ! if deuterium chemistry: hdo cross-section if (deutchem) then do ilay = 1,nlayer do iw = 1,nw-1 ! two chanels for hdo, with same cross-section sj(ilay,iw,j_hdo_od) = 0.5*xshdo(iw) ! hdo -> od + h sj(ilay,iw,j_hdo_d) = 0.5*xshdo(iw) ! hdo -> d + oh end do end do end if !==== set aerosol properties and optical depth call setaer(nlev,zalt,tau,nw,dtaer,omaer,gaer) !==== set cloud properties and optical depth call setcld(nlev,nw,dtcld,omcld,gcld) !==== slant path lengths in spherical geometry call sphers(nlev,zalt,sza,dsdh,nid) !==== solar flux at mars factor = (1./dist_sol)**2. do iw = 1,nw-1 fmars(iw) = f(iw)*factor end do !==== initialise photolysis rates v_phot(:,1:nphot) = 0. !==== start of wavelength lopp do iw = 1,nw-1 ! monochromatic radiative transfer. outputs are: ! normalized irradiances edir(nlev), edn(nlev), eup(nlev) ! normalized actinic fluxes fdir(nlev), fdn(nlev), fup(nlev) ! where ! dir = direct beam, dn = down-welling diffuse, up = up-welling diffuse call rtlink(nlev, nw, iw, albedo(iw), sza, dsdh, nid, dtrl, $ dagas, dtcld, omcld, gcld, dtaer, omaer, gaer, $ edir, edn, eup, fdir, fdn, fup) ! spherical actinic flux do ilay = 1,nlayer saflux(ilay) = fmars(iw)*(fdir(ilay) + fdn(ilay) + fup(ilay)) end do ! photolysis rate integration do i = 1,nphot do ilay = 1,nlayer deltaj = saflux(ilay)*sj(ilay,iw,i) v_phot(ilay,i) = v_phot(ilay,i) + deltaj*(wu(iw)-wl(iw)) end do end do ! eliminate small values where (v_phot(:,1:nphot) < 1.e-30) v_phot(:,1:nphot) = 0. end where end do ! iw contains !============================================================================== subroutine setair(nlev, nw, wl, wc, press, temp, zmmean, $ colinc, dtrl) *-----------------------------------------------------------------------------* *= PURPOSE: =* *= computes air column increments and rayleigh optical depth =* *-----------------------------------------------------------------------------* implicit none ! input: integer :: nlev, nw real, dimension(nw) :: wl, wc ! lower and central wavelength grid (nm) real, dimension(nlev) :: press, temp, zmmean ! pressure (hpa), temperature (k), molecular mass (g.mol-1) ! output: real, dimension(nlev) :: colinc ! air column increments (molecule.cm-2) real, dimension(nlev,nw) :: dtrl ! rayleigh optical depth ! local: real, parameter :: avo = 6.022e23 real, parameter :: g = 3.72 real :: dp, nu real, dimension(nw) :: srayl integer :: ilev, iw ! compute column increments do ilev = 1, nlev-1 dp = (press(ilev) - press(ilev+1))*100. colinc(ilev) = avo*0.1*dp/(zmmean(ilev)*g) end do colinc(nlev) = 0. do iw = 1, nw - 1 ! co2 rayleigh cross-section ! ityaksov et al., chem. phys. lett., 462, 31-34, 2008 nu = 1./(wc(iw)*1.e-7) srayl(iw) = 1.78e-26*nu**(4. + 0.625) srayl(iw) = srayl(iw)*1.e-20 ! cm2 do ilev = 1, nlev dtrl(ilev,iw) = colinc(ilev)*srayl(iw) ! cm2 end do end do end subroutine setair !============================================================================== subroutine setco2(nd, nlayer, nw, wc, tlay, xsco2_195, xsco2_295, $ xsco2_370, yieldco2, j_co2_o, j_co2_o1d, $ colinc, rm, dt, sj) !-----------------------------------------------------------------------------* != PURPOSE: =* != Set up the CO2 temperature-dependent cross-sections and optical depth =* !-----------------------------------------------------------------------------* implicit none ! input: integer :: nd ! number of photolysis rates integer :: nlayer ! number of vertical layers integer :: nw ! number of wavelength grid points integer :: j_co2_o, j_co2_o1d ! photolysis indexes real, dimension(nw) :: wc ! central wavelength for each interval real, dimension(nw) :: xsco2_195, xsco2_295, xsco2_370 ! co2 cross-sections (cm2) real, dimension(nw) :: yieldco2 ! co2 photodissociation yield real, dimension(nlayer) :: tlay ! temperature (k) real, dimension(nlayer) :: rm ! co2 mixing ratio real, dimension(nlayer) :: colinc ! air column increment (molecule.cm-2) ! output: real, dimension(nlayer,nw) :: dt ! optical depth real, dimension(nlayer,nw,nd) :: sj ! cross-section array (cm2) ! local: integer :: extrapol integer :: i, l real :: temp, sco2 ! extrapol = 0 no extrapolation below 195 k ! extrapol = 1 extrapolation below 195 k extrapol = 0 do i = 1, nlayer if (extrapol == 1) then temp = tlay(i) else temp = max(tlay(i), 195.) end if temp = min(temp, 370.) do l = 1, nw-1 if (temp <= 295.) then if (xsco2_195(l) /= 0. .and. xsco2_295(l) /= 0.) then sco2 = alog(xsco2_195(l)) $ + (alog(xsco2_295(l)) - alog(xsco2_195(l))) $ /(295. - 195.)*(temp - 195.) sco2 = exp(sco2) else sco2 = 0. end if else if (xsco2_295(l) /= 0. .and. xsco2_370(l) /= 0.) then sco2 = alog(xsco2_295(l)) $ + (alog(xsco2_370(l)) - alog(xsco2_295(l))) $ /(370. - 295.)*(temp - 295.) sco2 = exp(sco2) else sco2 = 0. end if end if ! optical depth dt(i,l) = colinc(i)*rm(i)*sco2 ! production of o(1d) for wavelengths shorter than 167 nm if (wc(l) >= 167.) then sj(i,l,j_co2_o) = sco2*yieldco2(l) sj(i,l,j_co2_o1d) = 0. else sj(i,l,j_co2_o) = 0. sj(i,l,j_co2_o1d) = sco2*yieldco2(l) end if end do end do end subroutine setco2 !============================================================================== subroutine seto2(nd, nlayer, nw, wc, mopt, tlay, xso2_150, $ xso2_200, xso2_250, xso2_300, yieldo2, j_o2_o, $ j_o2_o1d, colinc, rm, dt, sj) !-----------------------------------------------------------------------------* != PURPOSE: =* != Set up the O2 temperature-dependent cross-sections and optical depth =* !-----------------------------------------------------------------------------* implicit none ! input: integer :: nd ! number of photolysis rates integer :: nlayer ! number of vertical layers integer :: nw ! number of wavelength grid points integer :: mopt ! high-res/low-res switch integer :: j_o2_o, j_o2_o1d ! photolysis indexes real, dimension(nw) :: wc ! central wavelength for each interval real, dimension(nw) :: xso2_150, xso2_200, xso2_250, ! o2 cross-sections (cm2) $ xso2_300 real, dimension(nw) :: yieldo2 ! o2 photodissociation yield real, dimension(nlayer) :: tlay ! temperature (k) real, dimension(nlayer) :: rm ! o2 mixing ratio real, dimension(nlayer) :: colinc ! air column increment (molecule.cm-2) ! output: real, dimension(nlayer,nw) :: dt ! optical depth real, dimension(nlayer,nw,nd) :: sj ! cross-section array (cm2) ! local: integer :: ilev, iw real :: temp real :: xso2, factor ! correction by factor if low-resolution in schumann-runge bands if (mopt == 1) then factor = 1. else if (mopt == 2) then factor = 0.8 end if ! calculate temperature dependance do ilev = 1,nlayer temp = max(tlay(ilev),150.) temp = min(temp, 300.) do iw = 1, nw-1 if (tlay(ilev) > 250.) then xso2 = xso2_250(iw) + (xso2_300(iw) - xso2_250(iw)) $ /(300. - 250.)*(temp - 250.) else if (tlay(ilev) > 200.) then xso2 = xso2_200(iw) + (xso2_250(iw) - xso2_200(iw)) $ /(250. - 200.)*(temp - 200.) else xso2 = xso2_150(iw) + (xso2_200(iw) - xso2_150(iw)) $ /(200. - 150.)*(temp - 150.) end if if (wc(iw) > 180. .and. wc(iw) < 200.) then xso2 = xso2*factor end if ! optical depth dt(ilev,iw) = colinc(ilev)*rm(ilev)*xso2 ! production of o(1d) for wavelengths shorter than 175 nm if (wc(iw) >= 175.) then sj(ilev,iw,j_o2_o) = xso2*yieldo2(iw) sj(ilev,iw,j_o2_o1d) = 0. else sj(ilev,iw,j_o2_o) = 0. sj(ilev,iw,j_o2_o1d) = xso2*yieldo2(iw) end if end do end do end subroutine seto2 !============================================================================== subroutine seto3(nd, nlayer, nw, wc, tlay, xso3_218, xso3_298, $ j_o3_o, j_o3_o1d, $ colinc, rm, dt, sj) !-----------------------------------------------------------------------------* != PURPOSE: =* != Set up the O3 temperature dependent cross-sections and optical depth =* !-----------------------------------------------------------------------------* implicit none ! input: integer :: nd ! number of photolysis rates integer :: nlayer ! number of vertical layers integer :: nw ! number of wavelength grid points integer :: j_o3_o, j_o3_o1d ! photolysis indexes real, dimension(nw) :: wc ! central wavelength for each interval real, dimension(nw) :: xso3_218, xso3_298 ! o3 cross-sections (cm2) real, dimension(nlayer) :: tlay ! temperature (k) real, dimension(nlayer) :: rm ! o3 mixing ratio real, dimension(nlayer) :: colinc ! air column increment (molecule.cm-2) ! output: real, dimension(nlayer,nw) :: dt ! optical depth real, dimension(nlayer,nw,nd) :: sj ! cross-section array (cm2) ! local: ! integer :: ilev, iw real :: temp real, dimension(nw) :: xso3(nw) real, dimension(nw) :: qy1d ! quantum yield for o(1d) production real :: q1, q2, a1, a2, a3 do ilev = 1, nlayer temp = max(tlay(ilev), 218.) temp = min(temp,298.) do iw = 1, nw-1 xso3(iw) = xso3_218(iw) + (xso3_298(iw) - xso3_218(iw)) $ /(298. - 218.) *(temp - 218.) ! optical depth dt(ilev,iw) = colinc(ilev)*rm(ilev)*xso3(iw) end do ! calculate quantum yield for o(1d) production (jpl 2006) temp = max(tlay(ilev),200.) temp = min(temp,320.) do iw = 1, nw-1 if (wc(iw) <= 306.) then qy1d(iw) = 0.90 else if (wc(iw) > 306. .and. wc(iw) < 328.) then q1 = 1. q2 = exp(-825.518/(0.695*temp)) a1 = (304.225 - wc(iw))/5.576 a2 = (314.957 - wc(iw))/6.601 a3 = (310.737 - wc(iw))/2.187 qy1d(iw) = (q1/(q1 + q2))*0.8036*exp(-(a1*a1*a1*a1)) $ + (q2/(q1 + q2))*8.9061*(temp/300.)**2. $ *exp(-(a2*a2)) $ + 0.1192*(temp/300.)**1.5*exp(-(a3*a3)) $ + 0.0765 else if (wc(iw) >= 328. .and. wc(iw) <= 340.) then qy1d(iw) = 0.08 else qy1d(iw) = 0. endif end do do iw = 1, nw-1 sj(ilev,iw,j_o3_o) = xso3(iw)*(1. - qy1d(iw)) sj(ilev,iw,j_o3_o1d) = xso3(iw)*qy1d(iw) end do end do end subroutine seto3 !============================================================================== subroutine seth2o2(nd, nlayer, nw, wc, tlay, xsh2o2, j_h2o2, $ colinc, rm, dt, sj) !-----------------------------------------------------------------------------* != PURPOSE: =* != Set up the h2o2 temperature dependent cross-sections and optical depth =* !-----------------------------------------------------------------------------* implicit none ! input: integer :: nd ! number of photolysis rates integer :: nlayer ! number of vertical layers integer :: nw ! number of wavelength grid points integer :: j_h2o2 ! photolysis index real, dimension(nw) :: wc ! central wavelength for each interval real, dimension(nw) :: xsh2o2 ! h2o2 cross-sections (cm2) real, dimension(nlayer) :: tlay ! temperature (k) real, dimension(nlayer) :: rm ! h2o2 mixing ratio real, dimension(nlayer) :: colinc ! air column increment (molecule.cm-2) ! output: real, dimension(nlayer,nw) :: dt ! optical depth real, dimension(nlayer,nw,nd) :: sj ! cross-section array (cm2) ! local: integer :: ilev, iw real :: a0, a1, a2, a3, a4, a5, a6, a7 real :: b0, b1, b2, b3, b4 real :: lambda, suma, sumb, chi, temp, xs A0 = 6.4761E+04 A1 = -9.2170972E+02 A2 = 4.535649 A3 = -4.4589016E-03 A4 = -4.035101E-05 A5 = 1.6878206E-07 A6 = -2.652014E-10 A7 = 1.5534675E-13 B0 = 6.8123E+03 B1 = -5.1351E+01 B2 = 1.1522E-01 B3 = -3.0493E-05 B4 = -1.0924E-07 ! temperature dependance: jpl 2006 do ilev = 1,nlayer temp = min(max(tlay(ilev),200.),400.) chi = 1./(1. + exp(-1265./temp)) do iw = 1, nw-1 if ((wc(iw) >= 260.) .and. (wc(iw) < 350.)) then lambda = wc(iw) sumA = ((((((A7*lambda + A6)*lambda + A5)*lambda + $ A4)*lambda +A3)*lambda + A2)*lambda + $ A1)*lambda + A0 sumB = (((B4*lambda + B3)*lambda + B2)*lambda + $ B1)*lambda + B0 xs = (chi*sumA + (1. - chi)*sumB)*1.e-21 sj(ilev,iw,j_h2o2) = xs else sj(ilev,iw,j_h2o2) = xsh2o2(iw) end if ! optical depth dt(ilev,iw) = colinc(ilev)*rm(ilev)*sj(ilev,iw,j_h2o2) end do end do end subroutine seth2o2 !============================================================================== subroutine setno2(nd, nlayer, nw, wc, tlay, xsno2, xsno2_220, $ xsno2_294, yldno2_248, yldno2_298, j_no2, $ colinc, rm, dt, sj) !-----------------------------------------------------------------------------* != PURPOSE: =* != Set up the no2 temperature-dependent cross-sections and optical depth =* !-----------------------------------------------------------------------------* implicit none ! input: integer :: nd ! number of photolysis rates integer :: nlayer ! number of vertical layers integer :: nw ! number of wavelength grid points integer :: j_no2 ! photolysis index real, dimension(nw) :: wc ! central wavelength for each interval real, dimension(nw) :: xsno2, xsno2_220, xsno2_294 ! no2 absorption cross-section at 220-294 k (cm2) real, dimension(nw) :: yldno2_248, yldno2_298 ! no2 quantum yield at 248-298 k real, dimension(nlayer) :: tlay ! temperature (k) real, dimension(nlayer) :: rm ! no2 mixing ratio real, dimension(nlayer) :: colinc ! air column increment (molecule.cm-2) ! output: real, dimension(nlayer,nw) :: dt ! optical depth real, dimension(nlayer,nw,nd) :: sj ! cross-section array (cm2) ! local: integer :: ilev, iw real :: temp, qy ! temperature dependance: jpl 2006 do ilev = 1,nlayer temp = max(220.,min(tlay(ilev),294.)) do iw = 1, nw - 1 if (wc(iw) < 238.) then sj(ilev,iw,j_no2) = xsno2(iw) else sj(ilev,iw,j_no2) = xsno2_220(iw) $ + (xsno2_294(iw) - xsno2_220(iw)) $ /(294. - 220.)*(temp - 220.) end if ! optical depth dt(ilev,iw) = colinc(ilev)*rm(ilev)*sj(ilev,iw,j_no2) end do end do ! quantum yield: jpl 2006 do ilev = 1,nlayer temp = max(248.,min(tlay(ilev),298.)) do iw = 1, nw - 1 qy = yldno2_248(iw) + (yldno2_298(iw) - yldno2_248(iw)) $ /(298. - 248.)*(temp - 248.) sj(ilev,iw,j_no2) = sj(ilev,iw,j_no2)*qy end do end do end subroutine setno2 !============================================================================== subroutine setaer(nlev,zalt,tau,nw,dtaer,omaer,gaer) !-----------------------------------------------------------------------------* != PURPOSE: =* != Set aerosol properties for each specified altitude layer. Properties =* != may be wavelength dependent. =* !-----------------------------------------------------------------------------* implicit none ! input integer :: nlev ! number of vertical levels integer :: nw ! number of wavelength grid points real, dimension(nlev) :: zalt ! altitude (km) real :: tau ! integrated aerosol optical depth at the surface ! output real, dimension(nlev,nw) :: dtaer ! aerosol optical depth real, dimension(nlev,nw) :: omaer ! aerosol single scattering albedo real, dimension(nlev,nw) :: gaer ! aerosol asymmetry parameter ! local integer :: ilev, iw real, dimension(nlev) :: aer ! dust extinction real :: omega, g, scaleh, gamma real :: dz, tautot, q0 omega = 0.622 ! single scattering albedo : wolff et al.(2010) at 258 nm g = 0.88 ! asymmetry factor : mateshvili et al. (2007) at 210 nm scaleh = 10. ! scale height (km) gamma = 0.03 ! conrath parameter dtaer(:,:) = 0. omaer(:,:) = 0. gaer(:,:) = 0. ! optical depth profile: tautot = 0. do ilev = 1, nlev-1 dz = zalt(ilev+1) - zalt(ilev) tautot = tautot + exp(gamma*(1. - exp(zalt(ilev)/scaleh)))*dz end do q0 = tau/tautot do ilev = 1, nlev-1 dz = zalt(ilev+1) - zalt(ilev) dtaer(ilev,:) = q0*exp(gamma*(1. - exp(zalt(ilev)/scaleh)))*dz omaer(ilev,:) = omega gaer(ilev,:) = g end do end subroutine setaer !============================================================================== subroutine setcld(nlev,nw,dtcld,omcld,gcld) !-----------------------------------------------------------------------------* != PURPOSE: =* != Set cloud properties for each specified altitude layer. Properties =* != may be wavelength dependent. =* !-----------------------------------------------------------------------------* implicit none ! input integer :: nlev ! number of vertical levels integer :: nw ! number of wavelength grid points ! output real, dimension(nlev,nw) :: dtcld ! cloud optical depth real, dimension(nlev,nw) :: omcld ! cloud single scattering albedo real, dimension(nlev,nw) :: gcld ! cloud asymmetry parameter ! local integer :: ilev, iw ! dtcld : optical depth ! omcld : single scattering albedo ! gcld : asymmetry factor dtcld(:,:) = 0. do ilev = 1,nlev-1 do iw = 1,nw-1 dtcld(ilev,iw) = 0. ! no clouds for the moment omcld(ilev,iw) = 0.99 gcld(ilev,iw) = 0.85 end do end do end subroutine setcld !============================================================================== subroutine sphers(nlev, z, zen, dsdh, nid) !-----------------------------------------------------------------------------* != PURPOSE: =* != Calculate slant path over vertical depth ds/dh in spherical geometry. =* != Calculation is based on: A.Dahlback, and K.Stamnes, A new spheric model =* != for computing the radiation field available for photolysis and heating =* != at twilight, Planet.Space Sci., v39, n5, pp. 671-683, 1991 (Appendix B) =* !-----------------------------------------------------------------------------* != PARAMETERS: =* != NZ - INTEGER, number of specified altitude levels in the working (I)=* != grid =* != Z - REAL, specified altitude working grid (km) (I)=* != ZEN - REAL, solar zenith angle (degrees) (I)=* != DSDH - REAL, slant path of direct beam through each layer crossed (O)=* != when travelling from the top of the atmosphere to layer i; =* != DSDH(i,j), i = 0..NZ-1, j = 1..NZ-1 =* != NID - INTEGER, number of layers crossed by the direct beam when (O)=* != travelling from the top of the atmosphere to layer i; =* != NID(i), i = 0..NZ-1 =* !-----------------------------------------------------------------------------* implicit none ! input integer, intent(in) :: nlev real, dimension(nlev), intent(in) :: z real, intent(in) :: zen ! output INTEGER nid(0:nlev) REAL dsdh(0:nlev,nlev) ! more program constants REAL re, ze(nlev) REAL dr real radius parameter (radius = 3393.) ! local real :: pi, zenrad, rpsinz, rj, rjp1, dsj, dhj, ga, gb, sm integer :: i, j, k, id, nlay REAL zd(0:nlev-1) !----------------------------------------------------------------------------- pi = acos(-1.0) dr = pi/180. zenrad = zen*dr ! number of layers: nlay = nlev - 1 ! include the elevation above sea level to the radius of Mars: re = radius + z(1) ! correspondingly z changed to the elevation above Mars surface: DO k = 1, nlev ze(k) = z(k) - z(1) END DO ! inverse coordinate of z zd(0) = ze(nlev) DO k = 1, nlay zd(k) = ze(nlev - k) END DO ! initialise dsdh(i,j), nid(i) nid(:) = 0. dsdh(:,:) = 0. ! calculate ds/dh of every layer do i = 0,nlay rpsinz = (re + zd(i))*sin(zenrad) IF ( (zen .GT. 90.0) .AND. (rpsinz .LT. re) ) THEN nid(i) = -1 ELSE ! Find index of layer in which the screening height lies id = i if (zen > 90.) then do j = 1,nlay IF( (rpsinz .LT. ( zd(j-1) + re ) ) .AND. $ (rpsinz .GE. ( zd(j) + re )) ) id = j end do end if do j = 1,id sm = 1.0 IF (j .EQ. id .AND. id .EQ. i .AND. zen .GT. 90.0) $ sm = -1.0 rj = re + zd(j-1) rjp1 = re + zd(j) dhj = zd(j-1) - zd(j) ga = rj*rj - rpsinz*rpsinz gb = rjp1*rjp1 - rpsinz*rpsinz ga = max(ga, 0.) gb = max(gb, 0.) IF (id.GT.i .AND. j.EQ.id) THEN dsj = sqrt(ga) ELSE dsj = sqrt(ga) - sm*sqrt(gb) END IF dsdh(i,j) = dsj/dhj end do nid(i) = id end if end do ! i = 0,nlay end subroutine sphers !============================================================================== SUBROUTINE rtlink(nlev, nw, iw, ag, zen, dsdh, nid, dtrl, $ dagas, dtcld, omcld, gcld, dtaer, omaer, gaer, $ edir, edn, eup, fdir, fdn, fup) implicit none ! input integer, intent(in) :: nlev, nw, iw ! number of wavelength grid points REAL ag REAL zen REAL dsdh(0:nlev,nlev) INTEGER nid(0:nlev) REAL dtrl(nlev,nw) REAL dagas(nlev,nw) REAL dtcld(nlev,nw), omcld(nlev,nw), gcld(nlev,nw) REAL dtaer(nlev,nw), omaer(nlev,nw), gaer(nlev,nw) ! output REAL edir(nlev), edn(nlev), eup(nlev) REAL fdir(nlev), fdn(nlev), fup(nlev) ! local: REAL dt(nlev), om(nlev), g(nlev) REAL dtabs,dtsct,dscld,dsaer,dacld,daaer INTEGER i, ii real, parameter :: largest = 1.e+36 ! specific two ps2str REAL ediri(nlev), edni(nlev), eupi(nlev) REAL fdiri(nlev), fdni(nlev), fupi(nlev) logical, save :: delta = .true. !$OMP THREADPRIVATE(delta) !_______________________________________________________________________ ! initialize: do i = 1, nlev fdir(i) = 0. fup(i) = 0. fdn(i) = 0. edir(i) = 0. eup(i) = 0. edn(i) = 0. end do do i = 1, nlev - 1 dscld = dtcld(i,iw)*omcld(i,iw) dacld = dtcld(i,iw)*(1.-omcld(i,iw)) dsaer = dtaer(i,iw)*omaer(i,iw) daaer = dtaer(i,iw)*(1.-omaer(i,iw)) dtsct = dtrl(i,iw) + dscld + dsaer dtabs = dagas(i,iw) + dacld + daaer dtabs = amax1(dtabs,1./largest) dtsct = amax1(dtsct,1./largest) ! invert z-coordinate: ii = nlev - i dt(ii) = dtsct + dtabs om(ii) = dtsct/(dtsct + dtabs) IF(dtsct .EQ. 1./largest) om(ii) = 1./largest g(ii) = (gcld(i,iw)*dscld + $ gaer(i,iw)*dsaer)/dtsct end do ! call rt routine: call ps2str(nlev, zen, ag, dt, om, g, $ dsdh, nid, delta, $ fdiri, fupi, fdni, ediri, eupi, edni) ! output (invert z-coordinate) do i = 1, nlev ii = nlev - i + 1 fdir(i) = fdiri(ii) fup(i) = fupi(ii) fdn(i) = fdni(ii) edir(i) = ediri(ii) eup(i) = eupi(ii) edn(i) = edni(ii) end do end subroutine rtlink *=============================================================================* subroutine ps2str(nlev,zen,rsfc,tauu,omu,gu, $ dsdh, nid, delta, $ fdr, fup, fdn, edr, eup, edn) !-----------------------------------------------------------------------------* != PURPOSE: =* != Solve two-stream equations for multiple layers. The subroutine is based =* != on equations from: Toon et al., J.Geophys.Res., v94 (D13), Nov 20, 1989.=* != It contains 9 two-stream methods to choose from. A pseudo-spherical =* != correction has also been added. =* !-----------------------------------------------------------------------------* != PARAMETERS: =* != NLEVEL - INTEGER, number of specified altitude levels in the working (I)=* != grid =* != ZEN - REAL, solar zenith angle (degrees) (I)=* != RSFC - REAL, surface albedo at current wavelength (I)=* != TAUU - REAL, unscaled optical depth of each layer (I)=* != OMU - REAL, unscaled single scattering albedo of each layer (I)=* != GU - REAL, unscaled asymmetry parameter of each layer (I)=* != DSDH - REAL, slant path of direct beam through each layer crossed (I)=* != when travelling from the top of the atmosphere to layer i; =* != DSDH(i,j), i = 0..NZ-1, j = 1..NZ-1 =* != NID - INTEGER, number of layers crossed by the direct beam when (I)=* != travelling from the top of the atmosphere to layer i; =* != NID(i), i = 0..NZ-1 =* != DELTA - LOGICAL, switch to use delta-scaling (I)=* != .TRUE. -> apply delta-scaling =* != .FALSE.-> do not apply delta-scaling =* != FDR - REAL, contribution of the direct component to the total (O)=* != actinic flux at each altitude level =* != FUP - REAL, contribution of the diffuse upwelling component to (O)=* != the total actinic flux at each altitude level =* != FDN - REAL, contribution of the diffuse downwelling component to (O)=* != the total actinic flux at each altitude level =* != EDR - REAL, contribution of the direct component to the total (O)=* != spectral irradiance at each altitude level =* != EUP - REAL, contribution of the diffuse upwelling component to (O)=* != the total spectral irradiance at each altitude level =* != EDN - REAL, contribution of the diffuse downwelling component to (O)=* *= the total spectral irradiance at each altitude level =* !-----------------------------------------------------------------------------* implicit none ! input: INTEGER nlev REAL zen, rsfc REAL tauu(nlev), omu(nlev), gu(nlev) REAL dsdh(0:nlev,nlev) INTEGER nid(0:nlev) LOGICAL delta ! output: REAL fup(nlev),fdn(nlev),fdr(nlev) REAL eup(nlev),edn(nlev),edr(nlev) ! local: REAL tausla(0:nlev), tauc(0:nlev) REAL mu2(0:nlev), mu, sum ! internal coefficients and matrix REAL lam(nlev),taun(nlev),bgam(nlev) REAL e1(nlev),e2(nlev),e3(nlev),e4(nlev) REAL cup(nlev),cdn(nlev),cuptn(nlev),cdntn(nlev) REAL mu1(nlev) INTEGER row REAL a(2*nlev),b(2*nlev),d(2*nlev),e(2*nlev),y(2*nlev) ! other: REAL pifs, fdn0 REAL gi(nlev), omi(nlev), tempg REAL f, g, om REAL gam1, gam2, gam3, gam4 real, parameter :: largest = 1.e+36 real, parameter :: precis = 1.e-7 ! For calculations of Associated Legendre Polynomials for GAMA1,2,3,4 ! in delta-function, modified quadrature, hemispheric constant, ! Hybrid modified Eddington-delta function metods, p633,Table1. ! W.E.Meador and W.R.Weaver, GAS,1980,v37,p.630 ! W.J.Wiscombe and G.W. Grams, GAS,1976,v33,p2440, ! uncomment the following two lines and the appropriate statements further ! down. ! REAL YLM0, YLM2, YLM4, YLM6, YLM8, YLM10, YLM12, YLMS, BETA0, ! > BETA1, BETAn, amu1, subd REAL expon, expon0, expon1, divisr, temp, up, dn REAL ssfc INTEGER nlayer, mrows, lev INTEGER i, j ! Some additional program constants: real pi, dr REAL eps PARAMETER (eps = 1.E-3) !_______________________________________________________________________ ! MU = cosine of solar zenith angle ! RSFC = surface albedo ! TAUU = unscaled optical depth of each layer ! OMU = unscaled single scattering albedo ! GU = unscaled asymmetry factor ! KLEV = max dimension of number of layers in atmosphere ! NLAYER = number of layers in the atmosphere ! NLEVEL = nlayer + 1 = number of levels ! initial conditions: pi*solar flux = 1; diffuse incidence = 0 pifs = 1. fdn0 = 0. nlayer = nlev - 1 pi = acos(-1.) dr = pi/180. mu = COS(zen*dr) !************* compute coefficients for each layer: ! GAM1 - GAM4 = 2-stream coefficients, different for different approximations ! EXPON0 = calculation of e when TAU is zero ! EXPON1 = calculation of e when TAU is TAUN ! CUP and CDN = calculation when TAU is zero ! CUPTN and CDNTN = calc. when TAU is TAUN ! DIVISR = prevents division by zero do j = 0, nlev tauc(j) = 0. tausla(j) = 0. mu2(j) = 1./SQRT(largest) end do IF (.NOT. delta) THEN DO i = 1, nlayer gi(i) = gu(i) omi(i) = omu(i) taun(i) = tauu(i) END DO ELSE ! delta-scaling. Have to be done for delta-Eddington approximation, ! delta discrete ordinate, Practical Improved Flux Method, delta function, ! and Hybrid modified Eddington-delta function methods approximations DO i = 1, nlayer f = gu(i)*gu(i) gi(i) = (gu(i) - f)/(1 - f) omi(i) = (1 - f)*omu(i)/(1 - omu(i)*f) taun(i) = (1 - omu(i)*f)*tauu(i) END DO END IF ! calculate slant optical depth at the top of the atmosphere when zen>90. ! in this case, higher altitude of the top layer is recommended. IF (zen .GT. 90.0) THEN IF (nid(0) .LT. 0) THEN tausla(0) = largest ELSE sum = 0.0 DO j = 1, nid(0) sum = sum + 2.*taun(j)*dsdh(0,j) END DO tausla(0) = sum END IF END IF DO 11, i = 1, nlayer g = gi(i) om = omi(i) tauc(i) = tauc(i-1) + taun(i) ! stay away from 1 by precision. For g, also stay away from -1 tempg = AMIN1(abs(g),1. - precis) g = SIGN(tempg,g) om = AMIN1(om,1.-precis) ! calculate slant optical depth IF (nid(i) .LT. 0) THEN tausla(i) = largest ELSE sum = 0.0 DO j = 1, MIN(nid(i),i) sum = sum + taun(j)*dsdh(i,j) END DO DO j = MIN(nid(i),i)+1,nid(i) sum = sum + 2.*taun(j)*dsdh(i,j) END DO tausla(i) = sum IF (tausla(i) .EQ. tausla(i-1)) THEN mu2(i) = SQRT(largest) ELSE mu2(i) = (tauc(i)-tauc(i-1))/(tausla(i)-tausla(i-1)) mu2(i) = SIGN( AMAX1(ABS(mu2(i)),1./SQRT(largest)), $ mu2(i) ) END IF END IF !** the following gamma equations are from pg 16,289, Table 1 !** save mu1 for each approx. for use in converting irradiance to actinic flux ! Eddington approximation(Joseph et al., 1976, JAS, 33, 2452): c gam1 = (7. - om*(4. + 3.*g))/4. c gam2 = -(1. - om*(4. - 3.*g))/4. c gam3 = (2. - 3.*g*mu)/4. c gam4 = 1. - gam3 c mu1(i) = 0.5 * quadrature (Liou, 1973, JAS, 30, 1303-1326; 1974, JAS, 31, 1473-1475): c gam1 = 1.7320508*(2. - om*(1. + g))/2. c gam2 = 1.7320508*om*(1. - g)/2. c gam3 = (1. - 1.7320508*g*mu)/2. c gam4 = 1. - gam3 c mu1(i) = 1./sqrt(3.) * hemispheric mean (Toon et al., 1089, JGR, 94, 16287): gam1 = 2. - om*(1. + g) gam2 = om*(1. - g) gam3 = (2. - g*mu)/4. gam4 = 1. - gam3 mu1(i) = 0.5 * PIFM (Zdunkovski et al.,1980, Conrib.Atmos.Phys., 53, 147-166): c GAM1 = 0.25*(8. - OM*(5. + 3.*G)) c GAM2 = 0.75*OM*(1.-G) c GAM3 = 0.25*(2.-3.*G*MU) c GAM4 = 1. - GAM3 c mu1(i) = 0.5 * delta discrete ordinates (Schaller, 1979, Contrib.Atmos.Phys, 52, 17-26): c GAM1 = 0.5*1.7320508*(2. - OM*(1. + G)) c GAM2 = 0.5*1.7320508*OM*(1.-G) c GAM3 = 0.5*(1.-1.7320508*G*MU) c GAM4 = 1. - GAM3 c mu1(i) = 1./sqrt(3.) * Calculations of Associated Legendre Polynomials for GAMA1,2,3,4 * in delta-function, modified quadrature, hemispheric constant, * Hybrid modified Eddington-delta function metods, p633,Table1. * W.E.Meador and W.R.Weaver, GAS,1980,v37,p.630 * W.J.Wiscombe and G.W. Grams, GAS,1976,v33,p2440 c YLM0 = 2. c YLM2 = -3.*G*MU c YLM4 = 0.875*G**3*MU*(5.*MU**2-3.) c YLM6=-0.171875*G**5*MU*(15.-70.*MU**2+63.*MU**4) c YLM8=+0.073242*G**7*MU*(-35.+315.*MU**2-693.*MU**4 c *+429.*MU**6) c YLM10=-0.008118*G**9*MU*(315.-4620.*MU**2+18018.*MU**4 c *-25740.*MU**6+12155.*MU**8) c YLM12=0.003685*G**11*MU*(-693.+15015.*MU**2-90090.*MU**4 c *+218790.*MU**6-230945.*MU**8+88179.*MU**10) c YLMS=YLM0+YLM2+YLM4+YLM6+YLM8+YLM10+YLM12 c YLMS=0.25*YLMS c BETA0 = YLMS c c amu1=1./1.7320508 c YLM0 = 2. c YLM2 = -3.*G*amu1 c YLM4 = 0.875*G**3*amu1*(5.*amu1**2-3.) c YLM6=-0.171875*G**5*amu1*(15.-70.*amu1**2+63.*amu1**4) c YLM8=+0.073242*G**7*amu1*(-35.+315.*amu1**2-693.*amu1**4 c *+429.*amu1**6) c YLM10=-0.008118*G**9*amu1*(315.-4620.*amu1**2+18018.*amu1**4 c *-25740.*amu1**6+12155.*amu1**8) c YLM12=0.003685*G**11*amu1*(-693.+15015.*amu1**2-90090.*amu1**4 c *+218790.*amu1**6-230945.*amu1**8+88179.*amu1**10) c YLMS=YLM0+YLM2+YLM4+YLM6+YLM8+YLM10+YLM12 c YLMS=0.25*YLMS c BETA1 = YLMS c c BETAn = 0.25*(2. - 1.5*G-0.21875*G**3-0.085938*G**5 c *-0.045776*G**7) * Hybrid modified Eddington-delta function(Meador and Weaver,1980,JAS,37,630): c subd=4.*(1.-G*G*(1.-MU)) c GAM1 = (7.-3.*G*G-OM*(4.+3.*G)+OM*G*G*(4.*BETA0+3.*G))/subd c GAM2 =-(1.-G*G-OM*(4.-3.*G)-OM*G*G*(4.*BETA0+3.*G-4.))/subd c GAM3 = BETA0 c GAM4 = 1. - GAM3 c mu1(i) = (1. - g*g*(1.- mu) )/(2. - g*g) ***** * delta function (Meador, and Weaver, 1980, JAS, 37, 630): c GAM1 = (1. - OM*(1. - beta0))/MU c GAM2 = OM*BETA0/MU c GAM3 = BETA0 c GAM4 = 1. - GAM3 c mu1(i) = mu ***** * modified quadrature (Meador, and Weaver, 1980, JAS, 37, 630): c GAM1 = 1.7320508*(1. - OM*(1. - beta1)) c GAM2 = 1.7320508*OM*beta1 c GAM3 = BETA0 c GAM4 = 1. - GAM3 c mu1(i) = 1./sqrt(3.) * hemispheric constant (Toon et al., 1989, JGR, 94, 16287): c GAM1 = 2.*(1. - OM*(1. - betan)) c GAM2 = 2.*OM*BETAn c GAM3 = BETA0 c GAM4 = 1. - GAM3 c mu1(i) = 0.5 ***** * lambda = pg 16,290 equation 21 * big gamma = pg 16,290 equation 22 * if gam2 = 0., then bgam = 0. lam(i) = sqrt(gam1*gam1 - gam2*gam2) IF (gam2 .NE. 0.) THEN bgam(i) = (gam1 - lam(i))/gam2 ELSE bgam(i) = 0. END IF expon = EXP(-lam(i)*taun(i)) * e1 - e4 = pg 16,292 equation 44 e1(i) = 1. + bgam(i)*expon e2(i) = 1. - bgam(i)*expon e3(i) = bgam(i) + expon e4(i) = bgam(i) - expon * the following sets up for the C equations 23, and 24 * found on page 16,290 * prevent division by zero (if LAMBDA=1/MU, shift 1/MU^2 by EPS = 1.E-3 * which is approx equiv to shifting MU by 0.5*EPS* (MU)**3 expon0 = EXP(-tausla(i-1)) expon1 = EXP(-tausla(i)) divisr = lam(i)*lam(i) - 1./(mu2(i)*mu2(i)) temp = AMAX1(eps,abs(divisr)) divisr = SIGN(temp,divisr) up = om*pifs*((gam1 - 1./mu2(i))*gam3 + gam4*gam2)/divisr dn = om*pifs*((gam1 + 1./mu2(i))*gam4 + gam2*gam3)/divisr * cup and cdn are when tau is equal to zero * cuptn and cdntn are when tau is equal to taun cup(i) = up*expon0 cdn(i) = dn*expon0 cuptn(i) = up*expon1 cdntn(i) = dn*expon1 11 CONTINUE ***************** set up matrix ****** * ssfc = pg 16,292 equation 37 where pi Fs is one (unity). ssfc = rsfc*mu*EXP(-tausla(nlayer))*pifs * MROWS = the number of rows in the matrix mrows = 2*nlayer * the following are from pg 16,292 equations 39 - 43. * set up first row of matrix: i = 1 a(1) = 0. b(1) = e1(i) d(1) = -e2(i) e(1) = fdn0 - cdn(i) row=1 * set up odd rows 3 thru (MROWS - 1): i = 0 DO 20, row = 3, mrows - 1, 2 i = i + 1 a(row) = e2(i)*e3(i) - e4(i)*e1(i) b(row) = e1(i)*e1(i + 1) - e3(i)*e3(i + 1) d(row) = e3(i)*e4(i + 1) - e1(i)*e2(i + 1) e(row) = e3(i)*(cup(i + 1) - cuptn(i)) + $ e1(i)*(cdntn(i) - cdn(i + 1)) 20 CONTINUE * set up even rows 2 thru (MROWS - 2): i = 0 DO 30, row = 2, mrows - 2, 2 i = i + 1 a(row) = e2(i + 1)*e1(i) - e3(i)*e4(i + 1) b(row) = e2(i)*e2(i + 1) - e4(i)*e4(i + 1) d(row) = e1(i + 1)*e4(i + 1) - e2(i + 1)*e3(i + 1) e(row) = (cup(i + 1) - cuptn(i))*e2(i + 1) - $ (cdn(i + 1) - cdntn(i))*e4(i + 1) 30 CONTINUE * set up last row of matrix at MROWS: row = mrows i = nlayer a(row) = e1(i) - rsfc*e3(i) b(row) = e2(i) - rsfc*e4(i) d(row) = 0. e(row) = ssfc - cuptn(i) + rsfc*cdntn(i) * solve tri-diagonal matrix: CALL tridiag(a, b, d, e, y, mrows) **** unfold solution of matrix, compute output fluxes: row = 1 lev = 1 j = 1 * the following equations are from pg 16,291 equations 31 & 32 fdr(lev) = EXP( -tausla(0) ) edr(lev) = mu * fdr(lev) edn(lev) = fdn0 eup(lev) = y(row)*e3(j) - y(row + 1)*e4(j) + cup(j) fdn(lev) = edn(lev)/mu1(lev) fup(lev) = eup(lev)/mu1(lev) DO 60, lev = 2, nlayer + 1 fdr(lev) = EXP(-tausla(lev-1)) edr(lev) = mu *fdr(lev) edn(lev) = y(row)*e3(j) + y(row + 1)*e4(j) + cdntn(j) eup(lev) = y(row)*e1(j) + y(row + 1)*e2(j) + cuptn(j) fdn(lev) = edn(lev)/mu1(j) fup(lev) = eup(lev)/mu1(j) row = row + 2 j = j + 1 60 CONTINUE end subroutine ps2str *=============================================================================* subroutine tridiag(a,b,c,r,u,n) !_______________________________________________________________________ ! solves tridiagonal system. From Numerical Recipies, p. 40 !_______________________________________________________________________ IMPLICIT NONE ! input: INTEGER n REAL a, b, c, r DIMENSION a(n),b(n),c(n),r(n) ! output: REAL u DIMENSION u(n) ! local: INTEGER j REAL bet, gam DIMENSION gam(n) !_______________________________________________________________________ IF (b(1) .EQ. 0.) STOP 1001 bet = b(1) u(1) = r(1)/bet DO 11, j = 2, n gam(j) = c(j - 1)/bet bet = b(j) - a(j)*gam(j) IF (bet .EQ. 0.) STOP 2002 u(j) = (r(j) - a(j)*u(j - 1))/bet 11 CONTINUE DO 12, j = n - 1, 1, -1 u(j) = u(j) - gam(j + 1)*u(j + 1) 12 CONTINUE !_______________________________________________________________________ end subroutine tridiag end subroutine photolysis_online end module photolysis_online_mod