C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/pkg/fizhi/fizhi_swrad.F,v 1.12 2004/07/26 18:45:17 molod Exp $ C $Name: $ #include "FIZHI_OPTIONS.h" subroutine swrio (nymd,nhms,bi,bj,ndswr,myid,istrip,npcs, . low_level,mid_level, . pz,plz,plze,dpres,pkht,pkz,tz,qz,oz,co2, . albvisdr,albvisdf,albnirdr,albnirdf, . dtradsw,dtswclr,radswg,swgclr, . fdifpar,fdirpar,osr,osrclr, . im,jm,lm,ptop, . nswcld,cldsw,cswmo,nswlz,swlz, . lpnt,imstturb,qliqave,fccave,landtype,xlats,xlons) implicit none #ifdef ALLOW_DIAGNOSTICS #include "SIZE.h" #include "diagnostics_SIZE.h" #include "diagnostics.h" #endif c Input Variables c --------------- integer nymd,nhms,bi,bj,ndswr,myid,istrip,npcs integer mid_level,low_level integer im,jm,lm _RL ptop _RL pz(im,jm),plz(im,jm,lm),plze(im,jm,lm+1),dpres(im,jm,lm) _RL pkht(im,jm,lm+1),pkz(im,jm,lm) _RL tz(im,jm,lm),qz(im,jm,lm) _RL oz(im,jm,lm) _RL co2 _RL albvisdr(im,jm),albvisdf(im,jm),albnirdr(im,jm) _RL albnirdf(im,jm) _RL radswg(im,jm),swgclr(im,jm),fdifpar(im,jm),fdirpar(im,jm) _RL osr(im,jm),osrclr(im,jm),dtradsw(im,jm,lm),dtswclr(im,jm,lm) integer nswcld,nswlz _RL cldsw(im,jm,lm),cswmo(im,jm,lm),swlz(im,jm,lm) logical lpnt integer imstturb _RL qliqave(im,jm,lm),fccave(im,jm,lm) integer landtype(im,jm) _RL xlats(im,jm),xlons(im,jm) c Local Variables c --------------- integer i,j,L,nn,nsecf integer ntmstp,nymd2,nhms2 _RL getcon,grav,cp,undef _RL ra,alf,reffw,reffi,tminv parameter ( reffw = 10.0 ) parameter ( reffi = 65.0 ) _RL tdry(im,jm,lm) _RL TEMP1(im,jm) _RL TEMP2(im,jm) _RL zenith (im,jm) _RL cldtot (im,jm,lm) _RL cldmxo (im,jm,lm) _RL totcld (im,jm) _RL cldlow (im,jm) _RL cldmid (im,jm) _RL cldhi (im,jm) _RL taulow (im,jm) _RL taumid (im,jm) _RL tauhi (im,jm) _RL tautype(im,jm,lm,3) _RL tau(im,jm,lm) _RL albedo(im,jm) _RL PK(ISTRIP,lm) _RL qzl(ISTRIP,lm),CLRO(ISTRIP,lm) _RL TZL(ISTRIP,lm) _RL OZL(ISTRIP,lm) _RL PLE(ISTRIP,lm+1) _RL COSZ(ISTRIP) _RL dpstrip(ISTRIP,lm) _RL albuvdr(ISTRIP),albuvdf(ISTRIP) _RL albirdr(ISTRIP),albirdf(ISTRIP) _RL difpar (ISTRIP),dirpar (ISTRIP) _RL fdirir(istrip),fdifir(istrip) _RL fdiruv(istrip),fdifuv(istrip) _RL flux(istrip,lm+1) _RL fluxclr(istrip,lm+1) _RL dtsw(istrip,lm) _RL dtswc(istrip,lm) _RL taul (istrip,lm) _RL reff (istrip,lm,2) _RL tauc (istrip,lm,2) _RL taua (istrip,lm) _RL tstrip (istrip) logical first data first /.true./ C ********************************************************************** C **** INITIALIZATION **** C ********************************************************************** grav = getcon('GRAVITY') cp = getcon('CP') undef = getcon('UNDEF') NTMSTP = nsecf(NDSWR) TMINV = 1./float(ntmstp) C Compute Temperature from Theta C ------------------------------ do L=1,lm do j=1,jm do i=1,im tdry(i,j,L) = tz(i,j,L)*pkz(i,j,L) enddo enddo enddo if (first .and. myid.eq.0 ) then print * print *,'Low-Level Clouds are Grouped between levels: ', . lm,' and ',low_level print *,'Mid-Level Clouds are Grouped between levels: ', . low_level-1,' and ',mid_level print * first = .false. endif C ********************************************************************** C **** CALCULATE COSINE OF THE ZENITH ANGLE **** C ********************************************************************** CALL ASTRO ( NYMD, NHMS, XLATS,XLONS, im*jm, TEMP1,RA ) NYMD2 = NYMD NHMS2 = NHMS CALL TICK ( NYMD2, NHMS2, NTMSTP ) CALL ASTRO ( NYMD2, NHMS2, XLATS,XLONS, im*jm, TEMP2,RA ) do j = 1,jm do i = 1,im zenith(I,j) = TEMP1(I,j) + TEMP2(I,j) IF( zenith(I,j) .GT. 0.0 ) THEN zenith(I,j) = (2./3.)*( zenith(I,j)-TEMP2(I,j)*TEMP1(I,j) . / zenith(I,j) ) ENDIF ENDDO ENDDO C ********************************************************************** c **** Compute Two-Dimension Total Cloud Fraction (0-1) **** C ********************************************************************** c Initialize Clear Sky Probability for Low, Mid, and High Clouds c -------------------------------------------------------------- do j =1,jm do i =1,im cldlow(i,j) = 0.0 cldmid(i,j) = 0.0 cldhi (i,j) = 0.0 enddo enddo c Adjust cloud fractions and cloud liquid water due to moist turbulence c --------------------------------------------------------------------- if(imstturb.ne.0) then do L =1,lm do j =1,jm do i =1,im cldtot(i,j,L)=min(1.0,max(cldsw(i,j,L),fccave(i,j,L)/imstturb)) cldmxo(i,j,L)=min(1.0,cswmo(i,j,L)) swlz(i,j,L)=swlz(i,j,L)+qliqave(i,j,L)/imstturb enddo enddo enddo else do L =1,lm do j =1,jm do i =1,im cldtot(i,j,L) = min( 1.0,cldsw(i,j,L) ) cldmxo(i,j,L) = min( 1.0,cswmo(i,j,L) ) enddo enddo enddo endif c Compute 3-D Cloud Fractions c --------------------------- if( nswcld.ne.0 ) then do L = 1,lm do j = 1,jm do i = 1,im c Compute Low-Mid-High Maximum Overlap Cloud Fractions c ---------------------------------------------------- if( L.lt.mid_level ) then cldhi (i,j) = max( cldtot(i,j,L),cldhi (i,j) ) elseif( L.ge.mid_level .and. . L.lt.low_level ) then cldmid(i,j) = max( cldtot(i,j,L),cldmid(i,j) ) elseif( L.ge.low_level ) then cldlow(i,j) = max( cldtot(i,j,L),cldlow(i,j) ) endif enddo enddo enddo endif c Totcld => Product of Clear Sky Probabilities for Low, Mid, and High Clouds c -------------------------------------------------------------------------- do j = 1,jm do i = 1,im totcld(i,j) = 1.0 - (1.-cldhi (i,j)) . * (1.-cldmid(i,j)) . * (1.-cldlow(i,j)) enddo enddo c Compute Cloud Diagnostics c ------------------------- if(icldfrc.gt.0) then do j=1,jm do i=1,im qdiag(i,j,icldfrc,bi,bj) = qdiag(i,j,icldfrc,bi,bj) + totcld(i,j) enddo enddo ncldfrc = ncldfrc + 1 endif if( icldras.gt.0 ) then do L=1,lm do j=1,jm do i=1,im qdiag(i,j,icldras+L-1,bi,bj) = qdiag(i,j,icldras+L-1,bi,bj) + . cswmo(i,j,L) enddo enddo enddo ncldras = ncldras + 1 endif if( icldtot.gt.0 ) then do L=1,lm do j=1,jm do i=1,im qdiag(i,j,icldtot+L-1,bi,bj) = qdiag(i,j,icldtot+L-1,bi,bj) + . cldtot(i,j,L) enddo enddo enddo ncldtot = ncldtot + 1 endif if( icldlow.gt.0 ) then do j=1,jm do i=1,im qdiag(i,j,icldlow,bi,bj) = qdiag(i,j,icldlow,bi,bj) + cldlow(i,j) enddo enddo ncldlow = ncldlow + 1 endif if( icldmid.gt.0 ) then do j=1,jm do i=1,im qdiag(i,j,icldmid,bi,bj) = qdiag(i,j,icldmid,bi,bj) + cldmid(i,j) enddo enddo ncldmid = ncldmid + 1 endif if( icldhi.gt.0 ) then do j=1,jm do i=1,im qdiag(i,j,icldhi,bi,bj) = qdiag(i,j,icldhi,bi,bj) + cldhi(i,j) enddo enddo ncldhi = ncldhi + 1 endif if( ilzrad.gt.0 ) then do L=1,lm do j=1,jm do i=1,im qdiag(i,j,ilzrad+L-1,bi,bj) = qdiag(i,j,ilzrad+L-1,bi,bj) + . swlz(i,j,L)*1.0e6 enddo enddo enddo nlzrad = nlzrad + 1 endif c Albedo Diagnostics c ------------------ if( ialbvisdr.gt.0 ) then do j=1,jm do i=1,im qdiag(i,j,ialbvisdr,bi,bj) = qdiag(i,j,ialbvisdr,bi,bj) + . albvisdr(i,j) enddo enddo nalbvisdr = nalbvisdr + 1 endif if( ialbvisdf.gt.0 ) then do j=1,jm do i=1,im qdiag(i,j,ialbvisdf,bi,bj) = qdiag(i,j,ialbvisdf,bi,bj) + . albvisdf(i,j) enddo enddo nalbvisdf = nalbvisdf + 1 endif if( ialbnirdr.gt.0 ) then do j=1,jm do i=1,im qdiag(i,j,ialbnirdr,bi,bj) = qdiag(i,j,ialbnirdr,bi,bj) + . albnirdr(i,j) enddo enddo nalbnirdr = nalbnirdr + 1 endif if( ialbnirdf.gt.0 ) then do j=1,jm do i=1,im qdiag(i,j,ialbnirdf,bi,bj) = qdiag(i,j,ialbnirdf,bi,bj) + . albnirdf(i,j) enddo enddo nalbnirdf = nalbnirdf + 1 endif C Compute Optical Thicknesses and Diagnostics C ------------------------------------------- call opthk(tdry,plz,plze,swlz,cldtot,cldmxo,landtype,im,jm,lm, . tautype) do L = 1,lm do j = 1,jm do i = 1,im tau(i,j,L) = tautype(i,j,L,1)+tautype(i,j,L,2)+tautype(i,j,L,3) enddo enddo enddo if( itauave.gt.0 ) then do L=1,lm do j=1,jm do i=1,im qdiag(i,j,itauave+L-1,bi,bj) = qdiag(i,j,itauave+L-1,bi,bj) + . tau(i,j,L)*100/(plze(i,j,L+1)-plze(i,j,L)) enddo enddo enddo ntauave = ntauave + 1 endif if( itaucld.gt.0 ) then do L=1,lm do j=1,jm do i=1,im if( cldtot(i,j,L).ne.0.0 ) then qdiag(i,j,itaucld +L-1,bi,bj) = qdiag(i,j,itaucld +L-1,bi,bj) + . tau(i,j,L)*100/(plze(i,j,L+1)-plze(i,j,L)) qdiag(i,j,itaucldc+L-1,bi,bj) = . qdiag(i,j,itaucldc+L-1,bi,bj) + 1.0 endif enddo enddo enddo endif c Compute Low, Mid, and High Cloud Optical Depth Diagnostics c ---------------------------------------------------------- if( itaulow.ne.0 ) then do j = 1,jm do i = 1,im if( cldlow(i,j).ne.0.0 ) then taulow(i,j) = 0.0 do L = low_level,lm taulow(i,j) = taulow(i,j) + tau(i,j,L) enddo qdiag(i,j,itaulow,bi,bj ) = qdiag(i,j,itaulow,bi,bj ) + . taulow(i,j) qdiag(i,j,itaulowc,bi,bj) = qdiag(i,j,itaulowc,bi,bj) + 1.0 endif enddo enddo endif if( itaumid.ne.0 ) then do j = 1,jm do i = 1,im if( cldmid(i,j).ne.0.0 ) then taumid(i,j) = 0.0 do L = mid_level,low_level+1 taumid(i,j) = taumid(i,j) + tau(i,j,L) enddo qdiag(i,j,itaumid,bi,bj ) = qdiag(i,j,itaumid,bi,bj ) + . taumid(i,j) qdiag(i,j,itaumidc,bi,bj) = qdiag(i,j,itaumidc,bi,bj) + 1.0 endif enddo enddo endif if( itauhi.ne.0 ) then do j = 1,jm do i = 1,im if( cldhi(i,j).ne.0.0 ) then tauhi(i,j) = 0.0 do L = 1,mid_level+1 tauhi(i,j) = tauhi(i,j) + tau(i,j,L) enddo qdiag(i,j,itauhi,bi,bj ) = qdiag(i,j,itauhi,bi,bj ) + . tauhi(i,j) qdiag(i,j,itauhic,bi,bj) = qdiag(i,j,itauhic,bi,bj) + 1.0 endif enddo enddo endif C*********************************************************************** C **** LOOP OVER GLOBAL REGIONS **** C ********************************************************************** do 1000 nn = 1,npcs C ********************************************************************** C **** VARIABLE INITIALIZATION **** C ********************************************************************** CALL STRIP ( zenith,COSZ,im*jm,ISTRIP,1,NN ) CALL STRIP ( plze, ple ,im*jm,ISTRIP,lm+1,NN) CALL STRIP ( pkz , pk ,im*jm,ISTRIP,lm ,NN) CALL STRIP ( dpres,dpstrip,im*jm,ISTRIP,lm ,NN) CALL STRIP ( tdry, tzl ,im*jm,ISTRIP,lm ,NN) CALL STRIP ( qz , qzl ,im*jm,ISTRIP,lm ,NN) CALL STRIP ( oz , ozl ,im*jm,ISTRIP,lm ,NN) CALL STRIP ( tau , taul ,im*jm,ISTRIP,lm ,NN) CALL STRIP ( albvisdr,albuvdr,im*jm,ISTRIP,1,NN ) CALL STRIP ( albvisdf,albuvdf,im*jm,ISTRIP,1,NN ) CALL STRIP ( albnirdr,albirdr,im*jm,ISTRIP,1,NN ) CALL STRIP ( albnirdf,albirdf,im*jm,ISTRIP,1,NN ) call strip ( cldtot,clro,im*jm,istrip,lm,nn ) c Partition Tau between Water and Ice Particles c --------------------------------------------- do L= 1,lm do i= 1,istrip alf = min( max((tzl(i,l)-253.15)/20.,0.) ,1.) taua(i,L) = 0. if( alf.ne.0.0 .and. alf.ne.1.0 ) then tauc(i,L,1) = taul(i,L)/(1.+alf/(1-alf) * (reffi/reffw*0.80) ) tauc(i,L,2) = taul(i,L)/(1.+(1-alf)/alf * (reffw/reffi*1.25) ) endif if( alf.eq.0.0 ) then tauc(i,L,1) = taul(i,L) tauc(i,L,2) = 0.0 endif if( alf.eq.1.0 ) then tauc(i,L,1) = 0.0 tauc(i,L,2) = taul(i,L) endif reff(i,L,1) = reffi reff(i,L,2) = reffw enddo enddo call sorad ( istrip,1,1,lm,ple,tzl,qzl,ozl,co2, . tauc,reff,clro,mid_level,low_level,taua, . albirdr,albirdf,albuvdr,albuvdf,cosz, . flux,fluxclr,fdirir,fdifir,dirpar,difpar, . fdiruv,fdifuv ) C ********************************************************************** C **** Compute Mass-Weighted Theta Tendencies from Fluxes **** C ********************************************************************** do l=1,lm do i=1,istrip alf = grav*(ple(i,L+1)-ptop)/(cp*dpstrip(i,L)*100) dtsw (i,L) = alf*( flux (i,L)-flux (i,L+1) )/pk(i,L) dtswc(i,L) = alf*( fluxclr(i,L)-fluxclr(i,L+1) )/pk(i,L) enddo enddo call paste ( dtsw , dtradsw ,istrip,im*jm,lm,nn ) call paste ( dtswc, dtswclr ,istrip,im*jm,lm,nn ) call paste ( flux (1,1),osr ,istrip,im*jm,1,nn ) call paste ( fluxclr(1,1),osrclr,istrip,im*jm,1,nn ) call paste ( flux (1,lm+1),radswg,istrip,im*jm,1,nn ) call paste ( fluxclr(1,lm+1),swgclr,istrip,im*jm,1,nn ) call paste ( dirpar,fdirpar,istrip,im*jm,1,nn ) call paste ( difpar,fdifpar,istrip,im*jm,1,nn ) c Calculate Mean Albedo c --------------------- do i=1,istrip if( cosz(i).gt.0.0 ) then tstrip(i) = 1.0 - flux(i,lm+1)/ . ( fdirir(i)+fdifir(i)+dirpar(i)+difpar(i) + fdiruv(i)+fdifuv(i) ) if( tstrip(i).lt.0.0 ) tstrip(i) = undef else tstrip(i) = undef endif enddo call paste ( tstrip,albedo,istrip,im*jm,1,nn ) 1000 CONTINUE c Mean Albedo Diagnostic c ---------------------- if( ialbedo.gt.0 ) then do j=1,jm do i=1,im if( albedo(i,j).ne.undef ) then qdiag(i,j,ialbedo,bi,bj ) = qdiag(i,j,ialbedo,bi,bj )+albedo(i,j) qdiag(i,j,ialbedoc,bi,bj) = qdiag(i,j,ialbedoc,bi,bj) + 1.0 endif enddo enddo endif C ********************************************************************** C **** ZERO-OUT OR BUMP COUNTERS **** C ********************************************************************** nswlz = 0 nswcld = 0 imstturb = 0 do L = 1,lm do j = 1,jm do i = 1,im fccave(i,j,L) = 0. qliqave(i,j,L) = 0. enddo enddo enddo return end subroutine opthk ( tl,pl,ple,lz,cf,cfm,lwi,im,jm,lm,tau ) C*********************************************************************** C C PURPOSE: C ======== C Compute cloud optical thickness using temperature and C cloud fractions. C C INPUT: C ====== C tl ......... Temperature at Model Layers (K) C pl ......... Model Layer Pressures (mb) C ple ........ Model Edge Pressures (mb) C lz ......... Diagnosed Convective and Large-Scale Cloud Water (g/g) C cf ......... Total Cloud Fraction (Random + Maximum Overlap) C cfm ........ Maximum Overlap Cloud Fraction C lwi ........ Surface Land Type C im ......... Longitudinal dimension C jm ......... Latitudinal dimension C lm ......... Vertical dimension C C OUTPUT: C ======= C tau ........ Cloud Optical Thickness (non-dimensional) C tau(im,jm,lm,1): Suspended Ice C tau(im,jm,lm,2): Suspended Water C tau(im,jm,lm,3): Raindrops C C*********************************************************************** implicit none integer im,jm,lm,i,j,L _RL tl(im,jm,lm) _RL pl(im,jm,lm) _RL ple(im,jm,lm+1) _RL lz(im,jm,lm) _RL cf(im,jm,lm) _RL cfm(im,jm,lm) _RL tau(im,jm,lm,3) integer lwi(im,jm) _RL dp, alf, fracls, fraccu _RL tauice, tauh2o, tauras c Compute Cloud Optical Depths c ---------------------------- do L=1,lm do j=1,jm do i=1,im alf = min( max(( tl(i,j,L)-233.15)/20.,0.) ,1.) dp = ple(i,j,L+1)-ple(i,j,L) tau(i,j,L,1) = 0.0 tau(i,j,L,2) = 0.0 tau(i,j,L,3) = 0.0 if( cf(i,j,L).ne.0.0 ) then c Determine fraction of large-scale and cumulus clouds c ---------------------------------------------------- fracls = ( cf(i,j,L)-cfm(i,j,L) )/cf(i,j,L) fraccu = 1.0-fracls c Define tau for large-scale ice and water clouds c Note: tauice is scaled between (0.02 & .2) for: 0 < lz < 2 mg/kg over Land c Note: tauh2o is scaled between (0.20 & 20) for: 0 < lz < 5 mg/kg over Land c Note: tauh2o is scaled between (0.20 & 12) for: 0 < lz < 50 mg/kg over Ocean c ------------------------------------------------------------------------------- c Large-Scale Ice c --------------- tauice = max( 0.0002, 0.002*min(500*lz(i,j,L)*1000,1.0) ) tau(i,j,L,1) = fracls*(1-alf)*tauice*dp c Large-Scale Water c ----------------- C Over Land if( lwi(i,j).le.10 ) then tauh2o = max( 0.0020, 0.200*min(200*lz(i,j,L)*1000,1.0) ) tau(i,j,L,3) = fracls*alf*tauh2o*dp else C Non-Precipitation Clouds Over Ocean if( lz(i,j,L).eq.0.0 ) then tauh2o = .12 tau(i,j,L,2) = fracls*alf*tauh2o*dp else C Over Ocean tauh2o = max( 0.0020, 0.120*min( 20*lz(i,j,L)*1000,1.0) ) tau(i,j,L,3) = fracls*alf*tauh2o*dp endif endif c Sub-Grid Convective c ------------------- if( tl(i,j,L).gt.210.0 ) then tauras = .16 tau(i,j,L,3) = tau(i,j,L,3) + fraccu*tauras*dp else tauras = tauice tau(i,j,L,1) = tau(i,j,L,1) + fraccu*tauras*dp endif c Define tau for large-scale and cumulus clouds c --------------------------------------------- ccc tau(i,j,L) = ( fracls*( alf*tauh2o + (1-alf)*tauice ) ccc . + fraccu*tauras )*dp endif enddo enddo enddo return end subroutine sorad(m,n,ndim,np,pl,ta,wa,oa,co2, * taucld,reff,fcld,ict,icb, * taual,rsirbm,rsirdf,rsuvbm,rsuvdf,cosz, * flx,flc,fdirir,fdifir,fdirpar,fdifpar, * fdiruv,fdifuv) c******************************************************************** c c This routine computes solar fluxes due to the absoption by water c vapor, ozone, co2, o2, clouds, and aerosols and due to the c scattering by clouds, aerosols, and gases. c c This is a vectorized code. It computes the fluxes simultaneous for c (m x n) soundings, which is a subset of the (m x ndim) soundings. c In a global climate model, m and ndim correspond to the numbers of c grid boxes in the zonal and meridional directions, respectively. c c Ice and liquid cloud particles are allowed to co-exist in any of the c np layers. Two sets of cloud parameters are required as inputs, one c for ice paticles and the other for liquid particles. These parameters c are optical thickness (taucld) and effective particle size (reff). c c If no information is available for reff, a default value of c 10 micron for liquid water and 75 micron for ice can be used. c c Clouds are grouped into high, middle, and low clouds separated by the c level indices ict and icb. For detail, see the subroutine cldscale. c c----- Input parameters: c units size c number of soundings in zonal direction (m) n/d 1 c number of soundings in meridional direction (n) n/d 1 c maximum number of soundings in n/d 1 c meridional direction (ndim) c number of atmospheric layers (np) n/d 1 c level pressure (pl) mb m*ndim*(np+1) c layer temperature (ta) k m*ndim*np c layer specific humidity (wa) gm/gm m*ndim*np c layer ozone concentration (oa) gm/gm m*ndim*np c co2 mixing ratio by volumn (co2) parts/part 1 c cloud optical thickness (taucld) n/d m*ndim*np*2 c index 1 for ice particles c index 2 for liquid drops c effective cloud-particle size (reff) micrometer m*ndim*np*2 c index 1 for ice particles c index 2 for liquid drops c cloud amount (fcld) fraction m*ndim*np c level index separating high and middle n/d 1 c clouds (ict) c level index separating middle and low clouds n/d 1 c clouds (icb) c aerosol optical thickness (taual) n/d m*ndim*np c solar ir surface albedo for beam fraction m*ndim c radiation (rsirbm) c solar ir surface albedo for diffuse fraction m*ndim c radiation (rsirdf) c uv + par surface albedo for beam fraction m*ndim c radiation (rsuvbm) c uv + par surface albedo for diffuse fraction m*ndim c radiation (rsuvdf) c cosine of solar zenith angle (cosz) n/d m*ndim c c----- Output parameters c c all-sky flux (downward minus upward) (flx) fraction m*ndim*(np+1) c clear-sky flux (downward minus upward) (flc) fraction m*ndim*(np+1) c all-sky direct downward ir (0.7-10 micron) c flux at the surface (fdirir) fraction m*ndim c all-sky diffuse downward ir flux at c the surface (fdifir) fraction m*ndim c all-sky direct downward par (0.4-0.7 micron) c flux at the surface (fdirpar) fraction m*ndim c all-sky diffuse downward par flux at c the surface (fdifpar) fraction m*ndim * c----- Notes: c c (1) The unit of flux is fraction of the incoming solar radiation c at the top of the atmosphere. Therefore, fluxes should c be equal to flux multiplied by the extra-terrestrial solar c flux and the cosine of solar zenith angle. c (2) Clouds and aerosols can be included in any layers by specifying c fcld(i,j,k), taucld(i,j,k,*) and taual(i,j,k), k=1,np. c For an atmosphere without clouds and aerosols, c set fcld(i,j,k)=taucld(i,j,k,*)=taual(i,j,k)=0.0. c (3) Aerosol single scattering albedos and asymmetry c factors are specified in the subroutines solir and soluv. c (4) pl(i,j,1) is the pressure at the top of the model, and c pl(i,j,np+1) is the surface pressure. c (5) the pressure levels ict and icb correspond approximately c to 400 and 700 mb. c c************************************************************************** implicit none c-----Explicit Inline Directives #ifdef CRAY #ifdef f77 cfpp$ expand (expmn) #endif #endif _RL expmn c-----input parameters integer m,n,ndim,np,ict,icb _RL pl(m,ndim,np+1),ta(m,ndim,np),wa(m,ndim,np),oa(m,ndim,np) _RL taucld(m,ndim,np,2),reff(m,ndim,np,2) _RL fcld(m,ndim,np),taual(m,ndim,np) _RL rsirbm(m,ndim),rsirdf(m,ndim), * rsuvbm(m,ndim),rsuvdf(m,ndim),cosz(m,ndim),co2 c-----output parameters _RL flx(m,ndim,np+1),flc(m,ndim,np+1) _RL fdirir(m,ndim),fdifir(m,ndim) _RL fdirpar(m,ndim),fdifpar(m,ndim) _RL fdiruv(m,ndim),fdifuv(m,ndim) c-----temporary array integer i,j,k _RL cc(m,n,3),tauclb(m,n,np),tauclf(m,n,np) _RL dp(m,n,np),wh(m,n,np),oh(m,n,np),scal(m,n,np) _RL swh(m,n,np+1),so2(m,n,np+1),df(m,n,np+1) _RL sdf(m,n),sclr(m,n),csm(m,n),x c----------------------------------------------------------------- do j= 1, n do i= 1, m swh(i,j,1)=0. so2(i,j,1)=0. c-----csm is the effective secant of the solar zenith angle c see equation (12) of Lacis and Hansen (1974, JAS) csm(i,j)=35./sqrt(1224.*cosz(i,j)*cosz(i,j)+1.) enddo enddo do k= 1, np do j= 1, n do i= 1, m c-----compute layer thickness and pressure-scaling function. c indices for the surface level and surface layer c are np+1 and np, respectively. dp(i,j,k)=pl(i,j,k+1)-pl(i,j,k) scal(i,j,k)=dp(i,j,k)*(.5*(pl(i,j,k)+pl(i,j,k+1))/300.)**.8 c-----compute scaled water vapor amount, unit is g/cm**2 wh(i,j,k)=1.02*wa(i,j,k)*scal(i,j,k)* * (1.+0.00135*(ta(i,j,k)-240.)) swh(i,j,k+1)=swh(i,j,k)+wh(i,j,k) c-----compute ozone amount, unit is (cm-atm)stp. oh(i,j,k)=1.02*oa(i,j,k)*dp(i,j,k)*466.7 enddo enddo enddo c-----scale cloud optical thickness in each layer from taucld (with c cloud amount fcld) to tauclb and tauclf (with cloud amount cc). c tauclb is the scaled optical thickness for beam radiation and c tauclf is for diffuse radiation. call cldscale(m,n,ndim,np,cosz,fcld,taucld,ict,icb, * cc,tauclb,tauclf) c-----initialize fluxes for all-sky (flx), clear-sky (flc), and c flux reduction (df) do k=1, np+1 do j=1, n do i=1, m flx(i,j,k)=0. flc(i,j,k)=0. df(i,j,k)=0. enddo enddo enddo c-----compute solar ir fluxes call solir (m,n,ndim,np,wh,taucld,tauclb,tauclf,reff,ict,icb * ,fcld,cc,taual,csm,rsirbm,rsirdf,flx,flc,fdirir,fdifir) c-----compute and update uv and par fluxes call soluv (m,n,ndim,np,oh,dp,taucld,tauclb,tauclf,reff,ict,icb * ,fcld,cc,taual,csm,rsuvbm,rsuvdf,flx,flc * ,fdirpar,fdifpar,fdiruv,fdifuv) c-----compute scaled amount of o2 (so2), unit is (cm-atm)stp. do k= 1, np do j= 1, n do i= 1, m so2(i,j,k+1)=so2(i,j,k)+165.22*scal(i,j,k) enddo enddo enddo c-----compute flux reduction due to oxygen following c chou (J. climate, 1990). The fraction 0.0287 is the c extraterrestrial solar flux in the o2 bands. do k= 2, np+1 do j= 1, n do i= 1, m x=so2(i,j,k)*csm(i,j) df(i,j,k)=df(i,j,k)+0.0287*(1.-expmn(-0.00027*sqrt(x))) enddo enddo enddo c-----compute scaled amounts for co2 (so2). unit is (cm-atm)stp. do k= 1, np do j= 1, n do i= 1, m so2(i,j,k+1)=so2(i,j,k)+co2*789.*scal(i,j,k) enddo enddo enddo c-----compute and update flux reduction due to co2 following c chou (J. Climate, 1990) call flxco2(m,n,np,so2,swh,csm,df) c-----adjust for the effect of o2 cnd co2 on clear-sky fluxes. do k= 2, np+1 do j= 1, n do i= 1, m flc(i,j,k)=flc(i,j,k)-df(i,j,k) enddo enddo enddo c-----adjust for the all-sky fluxes due to o2 and co2. It is c assumed that o2 and co2 have no effects on solar radiation c below clouds. clouds are assumed randomly overlapped. do j=1,n do i=1,m sdf(i,j)=0.0 sclr(i,j)=1.0 enddo enddo do k=1,np do j=1,n do i=1,m c-----sclr is the fraction of clear sky. c sdf is the flux reduction below clouds. if(fcld(i,j,k).gt.0.01) then sdf(i,j)=sdf(i,j)+df(i,j,k)*sclr(i,j)*fcld(i,j,k) sclr(i,j)=sclr(i,j)*(1.-fcld(i,j,k)) endif flx(i,j,k+1)=flx(i,j,k+1)-sdf(i,j)-df(i,j,k+1)*sclr(i,j) enddo enddo enddo c-----adjust for the direct downward ir flux. do j= 1, n do i= 1, m x = (1.-rsirdf(i,j))*fdifir(i,j) + (1.-rsirbm(i,j))*fdirir(i,j) x = (-sdf(i,j)-df(i,j,np+1)*sclr(i,j))/x fdirir(i,j)=fdirir(i,j)*(1.+x) fdifir(i,j)=fdifir(i,j)*(1.+x) enddo enddo return end c******************************************************************** subroutine cldscale (m,n,ndim,np,cosz,fcld,taucld,ict,icb, * cc,tauclb,tauclf) c******************************************************************** c c This subroutine computes the covers of high, middle, and c low clouds and scales the cloud optical thickness. c c To simplify calculations in a cloudy atmosphere, clouds are c grouped into high, middle and low clouds separated by the levels c ict and icb (level 1 is the top of the atmosphere). c c Within each of the three groups, clouds are assumed maximally c overlapped, and the cloud cover (cc) of a group is the maximum c cloud cover of all the layers in the group. The optical thickness c (taucld) of a given layer is then scaled to new values (tauclb and c tauclf) so that the layer reflectance corresponding to the cloud c cover cc is the same as the original reflectance with optical c thickness taucld and cloud cover fcld. c c---input parameters c c number of grid intervals in zonal direction (m) c number of grid intervals in meridional direction (n) c maximum number of grid intervals in meridional direction (ndim) c number of atmospheric layers (np) c cosine of the solar zenith angle (cosz) c fractional cloud cover (fcld) c cloud optical thickness (taucld) c index separating high and middle clouds (ict) c index separating middle and low clouds (icb) c c---output parameters c c fractional cover of high, middle, and low clouds (cc) c scaled cloud optical thickness for beam radiation (tauclb) c scaled cloud optical thickness for diffuse radiation (tauclf) c c******************************************************************** implicit none c-----input parameters integer m,n,ndim,np,ict,icb _RL cosz(m,ndim),fcld(m,ndim,np),taucld(m,ndim,np,2) c-----output parameters _RL cc(m,n,3),tauclb(m,n,np),tauclf(m,n,np) c-----temporary variables integer i,j,k,im,it,ia,kk _RL fm,ft,fa,xai,taux c-----pre-computed table integer nm,nt,na parameter (nm=11,nt=9,na=11) _RL dm,dt,da,t1,caib(nm,nt,na),caif(nt,na) parameter (dm=0.1,dt=0.30103,da=0.1,t1=-0.9031) c-----include the pre-computed table for cai #include "cai-dat.h" c save caib,caif c-----clouds within each of the high, middle, and low clouds are c assumed maximally overlapped, and the cloud cover (cc) c for a group is the maximum cloud cover of all the layers c in the group do j=1,n do i=1,m cc(i,j,1)=0.0 cc(i,j,2)=0.0 cc(i,j,3)=0.0 enddo enddo do k=1,ict-1 do j=1,n do i=1,m cc(i,j,1)=max(cc(i,j,1),fcld(i,j,k)) enddo enddo enddo do k=ict,icb-1 do j=1,n do i=1,m cc(i,j,2)=max(cc(i,j,2),fcld(i,j,k)) enddo enddo enddo do k=icb,np do j=1,n do i=1,m cc(i,j,3)=max(cc(i,j,3),fcld(i,j,k)) enddo enddo enddo c-----scale the cloud optical thickness. c taucld(i,j,k,1) is the optical thickness for ice particles, and c taucld(i,j,k,2) is the optical thickness for liquid particles. do k=1,np if(k.lt.ict) then kk=1 elseif(k.ge.ict .and. k.lt.icb) then kk=2 else kk=3 endif do j=1,n do i=1,m tauclb(i,j,k) = 0.0 tauclf(i,j,k) = 0.0 taux=taucld(i,j,k,1)+taucld(i,j,k,2) if (taux.gt.0.05 .and. fcld(i,j,k).gt.0.01) then c-----normalize cloud cover fa=fcld(i,j,k)/cc(i,j,kk) c-----table look-up taux=min(taux,32.) fm=cosz(i,j)/dm ft=(log10(taux)-t1)/dt fa=fa/da im=int(fm+1.5) it=int(ft+1.5) ia=int(fa+1.5) im=max(im,2) it=max(it,2) ia=max(ia,2) im=min(im,nm-1) it=min(it,nt-1) ia=min(ia,na-1) fm=fm-float(im-1) ft=ft-float(it-1) fa=fa-float(ia-1) c-----scale cloud optical thickness for beam radiation. c the scaling factor, xai, is a function of the solar zenith c angle, optical thickness, and cloud cover. xai= (-caib(im-1,it,ia)*(1.-fm)+ * caib(im+1,it,ia)*(1.+fm))*fm*.5+caib(im,it,ia)*(1.-fm*fm) xai=xai+(-caib(im,it-1,ia)*(1.-ft)+ * caib(im,it+1,ia)*(1.+ft))*ft*.5+caib(im,it,ia)*(1.-ft*ft) xai=xai+(-caib(im,it,ia-1)*(1.-fa)+ * caib(im,it,ia+1)*(1.+fa))*fa*.5+caib(im,it,ia)*(1.-fa*fa) xai= xai-2.*caib(im,it,ia) xai=max(xai,0.0) tauclb(i,j,k) = taux*xai c-----scale cloud optical thickness for diffuse radiation. c the scaling factor, xai, is a function of the cloud optical c thickness and cover but not the solar zenith angle. xai= (-caif(it-1,ia)*(1.-ft)+ * caif(it+1,ia)*(1.+ft))*ft*.5+caif(it,ia)*(1.-ft*ft) xai=xai+(-caif(it,ia-1)*(1.-fa)+ * caif(it,ia+1)*(1.+fa))*fa*.5+caif(it,ia)*(1.-fa*fa) xai= xai-caif(it,ia) xai=max(xai,0.0) tauclf(i,j,k) = taux*xai endif enddo enddo enddo return end c*********************************************************************** subroutine solir (m,n,ndim,np,wh,taucld,tauclb,tauclf,reff, * ict,icb,fcld,cc,taual,csm,rsirbm,rsirdf,flx,flc,fdirir,fdifir) c************************************************************************ c compute solar flux in the infrared region. The spectrum is divided c into three bands: c c band wavenumber(/cm) wavelength (micron) c 1 1000-4400 2.27-10.0 c 2 4400-8200 1.22-2.27 c 3 8200-14300 0.70-1.22 c c----- Input parameters: units size c c number of soundings in zonal direction (m) n/d 1 c number of soundings in meridional direction (n) n/d 1 c maximum number of soundings in n/d 1 c meridional direction (ndim) c number of atmospheric layers (np) n/d 1 c layer water vapor content (wh) gm/cm^2 m*n*np c cloud optical thickness (taucld) n/d m*ndim*np*2 c index 1 for ice paticles c index 2 for liquid particles c scaled cloud optical thickness n/d m*n*np c for beam radiation (tauclb) c scaled cloud optical thickness n/d m*n*np c for diffuse radiation (tauclf) c effective cloud-particle size (reff) micrometer m*ndim*np*2 c index 1 for ice paticles c index 2 for liquid particles c level index separating high and n/d m*n c middle clouds (ict) c level index separating middle and n/d m*n c low clouds (icb) c cloud amount (fcld) fraction m*ndim*np c cloud amount of high, middle, and n/d m*n*3 c low clouds (cc) c aerosol optical thickness (taual) n/d m*ndim*np c cosecant of the solar zenith angle (csm) n/d m*n c near ir surface albedo for beam fraction m*ndim c radiation (rsirbm) c near ir surface albedo for diffuse fraction m*ndim c radiation (rsirdf) c c----- output (updated) parameters: c c all-sky flux (downward-upward) (flx) fraction m*ndim*(np+1) c clear-sky flux (downward-upward) (flc) fraction m*ndim*(np+1) c all-sky direct downward ir flux at c the surface (fdirir) fraction m*ndim c all-sky diffuse downward ir flux at c the surface (fdifir) fraction m*ndim c c----- note: the following parameters must be specified by users: c aerosol single scattering albedo (ssaal) n/d nband c aerosol asymmetry factor (asyal) n/d nband c c************************************************************************* implicit none c-----Explicit Inline Directives #ifdef CRAY #ifdef f77 cfpp$ expand (deledd) cfpp$ expand (sagpol) cfpp$ expand (expmn) #endif #endif _RL expmn c-----input parameters integer m,n,ndim,np,ict,icb _RL taucld(m,ndim,np,2),reff(m,ndim,np,2),fcld(m,ndim,np) _RL tauclb(m,n,np),tauclf(m,n,np),cc(m,n,3) _RL rsirbm(m,ndim),rsirdf(m,ndim) _RL wh(m,n,np),taual(m,ndim,np),csm(m,n) c-----output (updated) parameters _RL flx(m,ndim,np+1),flc(m,ndim,np+1) _RL fdirir(m,ndim),fdifir(m,ndim) c-----static parameters integer nk,nband parameter (nk=10,nband=3) _RL xk(nk),hk(nband,nk),ssaal(nband),asyal(nband) _RL aia(nband,3),awa(nband,3),aig(nband,3),awg(nband,3) c-----temporary array integer ib,ik,i,j,k _RL ssacl(m,n,np),asycl(m,n,np) _RL rr(m,n,np+1,2),tt(m,n,np+1,2),td(m,n,np+1,2), * rs(m,n,np+1,2),ts(m,n,np+1,2) _RL fall(m,n,np+1),fclr(m,n,np+1) _RL fsdir(m,n),fsdif(m,n) _RL tauwv,tausto,ssatau,asysto,tauto,ssato,asyto _RL taux,reff1,reff2,w1,w2,g1,g2 _RL ssaclt(m,n),asyclt(m,n) _RL rr1t(m,n),tt1t(m,n),td1t(m,n),rs1t(m,n),ts1t(m,n) _RL rr2t(m,n),tt2t(m,n),td2t(m,n),rs2t(m,n),ts2t(m,n) c-----water vapor absorption coefficient for 10 k-intervals. c unit: cm^2/gm data xk/ 1 0.0010, 0.0133, 0.0422, 0.1334, 0.4217, 2 1.334, 5.623, 31.62, 177.8, 1000.0/ c-----water vapor k-distribution function, c the sum of hk is 0.52926. unit: fraction data hk/ 1 .01074,.08236,.20673, .00360,.01157,.03497, 2 .00411,.01133,.03011, .00421,.01143,.02260, 3 .00389,.01240,.01336, .00326,.01258,.00696, 4 .00499,.01381,.00441, .00465,.00650,.00115, 5 .00245,.00244,.00026, .00145,.00094,.00000/ c-----aerosol single-scattering albedo and asymmetry factor data ssaal,asyal/nband*0.999,nband*0.850/ c-----coefficients for computing the single scattering albedo of c ice clouds from ssa=1-(aia(*,1)+aia(*,2)*reff+aia(*,3)*reff**2) data aia/ 1 .08938331, .00215346,-.00000260, 2 .00299387, .00073709, .00000746, 3 -.00001038,-.00000134, .00000000/ c-----coefficients for computing the single scattering albedo of c liquid clouds from ssa=1-(awa(*,1)+awa(*,2)*reff+awa(*,3)*reff**2) data awa/ 1 .01209318,-.00019934, .00000007, 2 .01784739, .00088757, .00000845, 3 -.00036910,-.00000650,-.00000004/ c-----coefficients for computing the asymmetry factor of ice clouds c from asycl=aig(*,1)+aig(*,2)*reff+aig(*,3)*reff**2 data aig/ 1 .84090400, .76098937, .74935228, 2 .00126222, .00141864, .00119715, 3 -.00000385,-.00000396,-.00000367/ c-----coefficients for computing the asymmetry factor of liquid clouds c from asycl=awg(*,1)+awg(*,2)*reff+awg(*,3)*reff**2 data awg/ 1 .83530748, .74513197, .79375035, 2 .00257181, .01370071, .00832441, 3 .00005519,-.00038203,-.00023263/ c-----initialize surface fluxes, reflectances, and transmittances do j= 1, n do i= 1, m fdirir(i,j)=0.0 fdifir(i,j)=0.0 rr(i,j,np+1,1)=rsirbm(i,j) rr(i,j,np+1,2)=rsirbm(i,j) rs(i,j,np+1,1)=rsirdf(i,j) rs(i,j,np+1,2)=rsirdf(i,j) td(i,j,np+1,1)=0.0 td(i,j,np+1,2)=0.0 tt(i,j,np+1,1)=0.0 tt(i,j,np+1,2)=0.0 ts(i,j,np+1,1)=0.0 ts(i,j,np+1,2)=0.0 enddo enddo c-----integration over spectral bands do 100 ib=1,nband c-----compute cloud single scattering albedo and asymmetry factor c for a mixture of ice and liquid particles. do k= 1, np do j= 1, n do i= 1, m ssaclt(i,j)=1.0 asyclt(i,j)=1.0 taux=taucld(i,j,k,1)+taucld(i,j,k,2) if (taux.gt.0.05 .and. fcld(i,j,k).gt.0.01) then reff1=min(reff(i,j,k,1),130.) reff2=min(reff(i,j,k,2),20.0) w1=(1.-(aia(ib,1)+(aia(ib,2)+ * aia(ib,3)*reff1)*reff1))*taucld(i,j,k,1) w2=(1.-(awa(ib,1)+(awa(ib,2)+ * awa(ib,3)*reff2)*reff2))*taucld(i,j,k,2) ssaclt(i,j)=(w1+w2)/taux g1=(aig(ib,1)+(aig(ib,2)+aig(ib,3)*reff1)*reff1)*w1 g2=(awg(ib,1)+(awg(ib,2)+awg(ib,3)*reff2)*reff2)*w2 asyclt(i,j)=(g1+g2)/(w1+w2) endif enddo enddo do j=1,n do i=1,m ssacl(i,j,k)=ssaclt(i,j) enddo enddo do j=1,n do i=1,m asycl(i,j,k)=asyclt(i,j) enddo enddo enddo c-----integration over the k-distribution function do 200 ik=1,nk do 300 k= 1, np do j= 1, n do i= 1, m tauwv=xk(ik)*wh(i,j,k) c-----compute total optical thickness, single scattering albedo, c and asymmetry factor. tausto=tauwv+taual(i,j,k)+1.0e-8 ssatau=ssaal(ib)*taual(i,j,k) asysto=asyal(ib)*ssaal(ib)*taual(i,j,k) c-----compute reflectance and transmittance for cloudless layers tauto=tausto ssato=ssatau/tauto+1.0e-8 c if (ssato .gt. 0.001) then c ssato=min(ssato,0.999999) c asyto=asysto/(ssato*tauto) c call deledd(tauto,ssato,asyto,csm(i,j), c * rr1t(i,j),tt1t(i,j),td1t(i,j)) c call sagpol (tauto,ssato,asyto,rs1t(i,j),ts1t(i,j)) c else td1t(i,j)=expmn(-tauto*csm(i,j)) ts1t(i,j)=expmn(-1.66*tauto) tt1t(i,j)=0.0 rr1t(i,j)=0.0 rs1t(i,j)=0.0 c endif c-----compute reflectance and transmittance for cloud layers if (tauclb(i,j,k) .lt. 0.01) then rr2t(i,j)=rr1t(i,j) tt2t(i,j)=tt1t(i,j) td2t(i,j)=td1t(i,j) rs2t(i,j)=rs1t(i,j) ts2t(i,j)=ts1t(i,j) else tauto=tausto+tauclb(i,j,k) ssato=(ssatau+ssacl(i,j,k)*tauclb(i,j,k))/tauto+1.0e-8 ssato=min(ssato,0.999999) asyto=(asysto+asycl(i,j,k)*ssacl(i,j,k)*tauclb(i,j,k))/ * (ssato*tauto) call deledd(tauto,ssato,asyto,csm(i,j), * rr2t(i,j),tt2t(i,j),td2t(i,j)) tauto=tausto+tauclf(i,j,k) ssato=(ssatau+ssacl(i,j,k)*tauclf(i,j,k))/tauto+1.0e-8 ssato=min(ssato,0.999999) asyto=(asysto+asycl(i,j,k)*ssacl(i,j,k)*tauclf(i,j,k))/ * (ssato*tauto) call sagpol (tauto,ssato,asyto,rs2t(i,j),ts2t(i,j)) endif enddo enddo c-----the following code appears to be awkward, but it is efficient c in certain parallel processors. do j=1,n do i=1,m rr(i,j,k,1)=rr1t(i,j) enddo enddo do j=1,n do i=1,m tt(i,j,k,1)=tt1t(i,j) enddo enddo do j=1,n do i=1,m td(i,j,k,1)=td1t(i,j) enddo enddo do j=1,n do i=1,m rs(i,j,k,1)=rs1t(i,j) enddo enddo do j=1,n do i=1,m ts(i,j,k,1)=ts1t(i,j) enddo enddo do j=1,n do i=1,m rr(i,j,k,2)=rr2t(i,j) enddo enddo do j=1,n do i=1,m tt(i,j,k,2)=tt2t(i,j) enddo enddo do j=1,n do i=1,m td(i,j,k,2)=td2t(i,j) enddo enddo do j=1,n do i=1,m rs(i,j,k,2)=rs2t(i,j) enddo enddo do j=1,n do i=1,m ts(i,j,k,2)=ts2t(i,j) enddo enddo 300 continue c-----flux calculations call cldflx (m,n,np,ict,icb,cc,rr,tt,td,rs,ts, * fclr,fall,fsdir,fsdif) do k= 1, np+1 do j= 1, n do i= 1, m flx(i,j,k) = flx(i,j,k)+fall(i,j,k)*hk(ib,ik) enddo enddo do j= 1, n do i= 1, m flc(i,j,k) = flc(i,j,k)+fclr(i,j,k)*hk(ib,ik) enddo enddo enddo do j= 1, n do i= 1, m fdirir(i,j) = fdirir(i,j)+fsdir(i,j)*hk(ib,ik) fdifir(i,j) = fdifir(i,j)+fsdif(i,j)*hk(ib,ik) enddo enddo 200 continue 100 continue return end c************************************************************************ subroutine soluv (m,n,ndim,np,oh,dp,taucld,tauclb,tauclf,reff, * ict,icb,fcld,cc,taual,csm,rsuvbm,rsuvdf,flx,flc * ,fdirpar,fdifpar,fdiruv,fdifuv) c************************************************************************ c compute solar fluxes in the uv+visible region. the spectrum is c grouped into 8 bands: c c Band Micrometer c c UV-C 1. .175 - .225 c 2. .225 - .245 c .260 - .280 c 3. .245 - .260 c c UV-B 4. .280 - .295 c 5. .295 - .310 c 6. .310 - .320 c c UV-A 7. .320 - .400 c c PAR 8. .400 - .700 c c----- Input parameters: units size c c number of soundings in zonal direction (m) n/d 1 c number of soundings in meridional direction (n) n/d 1 c maximum number of soundings in n/d 1 c meridional direction (ndim) c number of atmospheric layers (np) n/d 1 c layer ozone content (oh) (cm-atm)stp m*n*np c layer pressure thickness (dp) mb m*n*np c cloud optical thickness (taucld) n/d m*ndim*np*2 c index 1 for ice paticles c index 2 for liquid particles c scaled cloud optical thickness n/d m*n*np c for beam radiation (tauclb) c scaled cloud optical thickness n/d m*n*np c for diffuse radiation (tauclf) c effective cloud-particle size (reff) micrometer m*ndim*np*2 c index 1 for ice paticles c index 2 for liquid particles c level indiex separating high and n/d m*n c middle clouds (ict) c level indiex separating middle and n/d m*n c low clouds (icb) c cloud amount (fcld) fraction m*ndim*np c cloud amounts of high, middle, and n/d m*n*3 c low clouds (cc) c aerosol optical thickness (taual) n/d m*ndim*np c cosecant of the solar zenith angle (csm) n/d m*n c uv+par surface albedo for beam fraction m*ndim c radiation (rsuvbm) c uv+par surface albedo for diffuse fraction m*ndim c radiation (rsuvdf) c c----- output (updated) parameters: c c all-sky net downward flux (flx) fraction m*ndim*(np+1) c clear-sky net downward flux (flc) fraction m*ndim*(np+1) c all-sky direct downward par flux at c the surface (fdirpar) fraction m*ndim c all-sky diffuse downward par flux at c the surface (fdifpar) fraction m*ndim c c----- note: the following parameters must be specified by users: c c aerosol single scattering albedo (ssaal) n/d 1 c aerosol asymmetry factor (asyal) n/d 1 c * c*********************************************************************** implicit none c-----Explicit Inline Directives #ifdef CRAY #ifdef f77 cfpp$ expand (deledd) cfpp$ expand (sagpol) #endif #endif c-----input parameters integer m,n,ndim,np,ict,icb _RL taucld(m,ndim,np,2),reff(m,ndim,np,2),fcld(m,ndim,np) _RL tauclb(m,n,np),tauclf(m,n,np),cc(m,n,3) _RL oh(m,n,np),dp(m,n,np),taual(m,ndim,np) _RL rsuvbm(m,ndim),rsuvdf(m,ndim),csm(m,n) c-----output (updated) parameter _RL flx(m,ndim,np+1),flc(m,ndim,np+1) _RL fdirpar(m,ndim),fdifpar(m,ndim) _RL fdiruv(m,ndim),fdifuv(m,ndim) c-----static parameters integer nband parameter (nband=8) _RL hk(nband),xk(nband),ry(nband) _RL asyal(nband),ssaal(nband),aig(3),awg(3) c-----temporary array integer i,j,k,ib _RL taurs,tauoz,tausto,ssatau,asysto,tauto,ssato,asyto _RL taux,reff1,reff2,g1,g2,asycl(m,n,np) _RL td(m,n,np+1,2),rr(m,n,np+1,2),tt(m,n,np+1,2), * rs(m,n,np+1,2),ts(m,n,np+1,2) _RL fall(m,n,np+1),fclr(m,n,np+1),fsdir(m,n),fsdif(m,n) _RL asyclt(m,n) _RL rr1t(m,n),tt1t(m,n),td1t(m,n),rs1t(m,n),ts1t(m,n) _RL rr2t(m,n),tt2t(m,n),td2t(m,n),rs2t(m,n),ts2t(m,n) c-----hk is the fractional extra-terrestrial solar flux. c the sum of hk is 0.47074. data hk/.00057, .00367, .00083, .00417, * .00600, .00556, .05913, .39081/ c-----xk is the ozone absorption coefficient. unit: /(cm-atm)stp data xk /30.47, 187.2, 301.9, 42.83, * 7.09, 1.25, 0.0345, 0.0539/ c-----ry is the extinction coefficient for Rayleigh scattering. c unit: /mb. data ry /.00604, .00170, .00222, .00132, * .00107, .00091, .00055, .00012/ c-----aerosol single-scattering albedo and asymmetry factor data ssaal,asyal/nband*0.999,nband*0.850/ c-----coefficients for computing the asymmetry factor of ice clouds c from asycl=aig(*,1)+aig(*,2)*reff+aig(*,3)*reff**2 data aig/.74625000,.00105410,-.00000264/ c-----coefficients for computing the asymmetry factor of liquid c clouds from asycl=awg(*,1)+awg(*,2)*reff+awg(*,3)*reff**2 data awg/.82562000,.00529000,-.00014866/ c-----initialize surface reflectances and transmittances do j= 1, n do i= 1, m rr(i,j,np+1,1)=rsuvbm(i,j) rr(i,j,np+1,2)=rsuvbm(i,j) rs(i,j,np+1,1)=rsuvdf(i,j) rs(i,j,np+1,2)=rsuvdf(i,j) td(i,j,np+1,1)=0.0 td(i,j,np+1,2)=0.0 tt(i,j,np+1,1)=0.0 tt(i,j,np+1,2)=0.0 ts(i,j,np+1,1)=0.0 ts(i,j,np+1,2)=0.0 enddo enddo c-----compute cloud asymmetry factor for a mixture of c liquid and ice particles. unit of reff is micrometers. do k= 1, np do j= 1, n do i= 1, m asyclt(i,j)=1.0 taux=taucld(i,j,k,1)+taucld(i,j,k,2) if (taux.gt.0.05 .and. fcld(i,j,k).gt.0.01) then reff1=min(reff(i,j,k,1),130.) reff2=min(reff(i,j,k,2),20.0) g1=(aig(1)+(aig(2)+aig(3)*reff1)*reff1)*taucld(i,j,k,1) g2=(awg(1)+(awg(2)+awg(3)*reff2)*reff2)*taucld(i,j,k,2) asyclt(i,j)=(g1+g2)/taux endif enddo enddo do j=1,n do i=1,m asycl(i,j,k)=asyclt(i,j) enddo enddo enddo do j=1,n do i=1,m fdiruv(i,j)=0.0 fdifuv(i,j)=0.0 enddo enddo c-----integration over spectral bands do 100 ib=1,nband do 300 k= 1, np do j= 1, n do i= 1, m c-----compute ozone and rayleigh optical thicknesses taurs=ry(ib)*dp(i,j,k) tauoz=xk(ib)*oh(i,j,k) c-----compute total optical thickness, single scattering albedo, c and asymmetry factor tausto=taurs+tauoz+taual(i,j,k)+1.0e-8 ssatau=ssaal(ib)*taual(i,j,k)+taurs asysto=asyal(ib)*ssaal(ib)*taual(i,j,k) c-----compute reflectance and transmittance for cloudless layers tauto=tausto ssato=ssatau/tauto+1.0e-8 ssato=min(ssato,0.999999) asyto=asysto/(ssato*tauto) call deledd(tauto,ssato,asyto,csm(i,j), * rr1t(i,j),tt1t(i,j),td1t(i,j)) call sagpol (tauto,ssato,asyto,rs1t(i,j),ts1t(i,j)) c-----compute reflectance and transmittance for cloud layers if (tauclb(i,j,k) .lt. 0.01) then rr2t(i,j)=rr1t(i,j) tt2t(i,j)=tt1t(i,j) td2t(i,j)=td1t(i,j) rs2t(i,j)=rs1t(i,j) ts2t(i,j)=ts1t(i,j) else tauto=tausto+tauclb(i,j,k) ssato=(ssatau+tauclb(i,j,k))/tauto+1.0e-8 ssato=min(ssato,0.999999) asyto=(asysto+asycl(i,j,k)*tauclb(i,j,k))/(ssato*tauto) call deledd(tauto,ssato,asyto,csm(i,j), * rr2t(i,j),tt2t(i,j),td2t(i,j)) tauto=tausto+tauclf(i,j,k) ssato=(ssatau+tauclf(i,j,k))/tauto+1.0e-8 ssato=min(ssato,0.999999) asyto=(asysto+asycl(i,j,k)*tauclf(i,j,k))/(ssato*tauto) call sagpol (tauto,ssato,asyto,rs2t(i,j),ts2t(i,j)) endif enddo enddo do j=1,n do i=1,m rr(i,j,k,1)=rr1t(i,j) enddo enddo do j=1,n do i=1,m tt(i,j,k,1)=tt1t(i,j) enddo enddo do j=1,n do i=1,m td(i,j,k,1)=td1t(i,j) enddo enddo do j=1,n do i=1,m rs(i,j,k,1)=rs1t(i,j) enddo enddo do j=1,n do i=1,m ts(i,j,k,1)=ts1t(i,j) enddo enddo do j=1,n do i=1,m rr(i,j,k,2)=rr2t(i,j) enddo enddo do j=1,n do i=1,m tt(i,j,k,2)=tt2t(i,j) enddo enddo do j=1,n do i=1,m td(i,j,k,2)=td2t(i,j) enddo enddo do j=1,n do i=1,m rs(i,j,k,2)=rs2t(i,j) enddo enddo do j=1,n do i=1,m ts(i,j,k,2)=ts2t(i,j) enddo enddo 300 continue c-----flux calculations call cldflx (m,n,np,ict,icb,cc,rr,tt,td,rs,ts, * fclr,fall,fsdir,fsdif) do k= 1, np+1 do j= 1, n do i= 1, m flx(i,j,k)=flx(i,j,k)+fall(i,j,k)*hk(ib) enddo enddo do j= 1, n do i= 1, m flc(i,j,k)=flc(i,j,k)+fclr(i,j,k)*hk(ib) enddo enddo enddo if(ib.eq.nband) then do j=1,n do i=1,m fdirpar(i,j)=fsdir(i,j)*hk(ib) fdifpar(i,j)=fsdif(i,j)*hk(ib) enddo enddo else do j=1,n do i=1,m fdiruv(i,j)=fdiruv(i,j)+fsdir(i,j)*hk(ib) fdifuv(i,j)=fdifuv(i,j)+fsdif(i,j)*hk(ib) enddo enddo endif 100 continue return end c********************************************************************* subroutine deledd(tau,ssc,g0,csm,rr,tt,td) c********************************************************************* c c-----uses the delta-eddington approximation to compute the c bulk scattering properties of a single layer c coded following King and Harshvardhan (JAS, 1986) c c inputs: c c tau: the effective optical thickness c ssc: the effective single scattering albedo c g0: the effective asymmetry factor c csm: the effective secant of the zenith angle c c outputs: c c rr: the layer reflection of the direct beam c tt: the layer diffuse transmission of the direct beam c td: the layer direct transmission of the direct beam c********************************************************************* implicit none c-----Explicit Inline Directives #ifdef CRAY #ifdef f77 cfpp$ expand (expmn) #endif #endif _RL expmn _RL zero,one,two,three,four,fourth,seven,tumin parameter (one=1., three=3.) parameter (seven=7., two=2.) parameter (four=4., fourth=.25) parameter (zero=0., tumin=1.e-20) c-----input parameters _RL tau,ssc,g0,csm c-----output parameters _RL rr,tt,td c-----temporary parameters _RL zth,ff,xx,taup,sscp,gp,gm1,gm2,gm3,akk,alf1,alf2, * all,bll,st7,st8,cll,dll,fll,ell,st1,st2,st3,st4 c zth = one / csm c delta-eddington scaling of single scattering albedo, c optical thickness, and asymmetry factor, c K & H eqs(27-29) ff = g0*g0 xx = one-ff*ssc taup= tau*xx sscp= ssc*(one-ff)/xx gp = g0/(one+g0) c extinction of the direct beam transmission td = expmn(-taup*csm) c gamma1, gamma2, gamma3 and gamma4. see table 2 and eq(26) K & H c ssc and gp are the d-s single scattering c albedo and asymmetry factor. xx = three*gp gm1 = (seven - sscp*(four+xx))*fourth gm2 = -(one - sscp*(four-xx))*fourth gm3 = (two - zth*xx )*fourth c akk is k as defined in eq(25) of K & H xx = gm1-gm2 akk = sqrt((gm1+gm2)*xx) c alf1 and alf2 are alpha1 and alpha2 from eqs (23) & (24) of K & H alf1 = gm1 - gm3 * xx alf2 = gm2 + gm3 * xx c all is last term in eq(21) of K & H c bll is last term in eq(22) of K & H xx = akk * two all = (gm3 - alf2 * zth )*xx*td bll = (one - gm3 + alf1*zth)*xx xx = akk * zth st7 = one - xx st8 = one + xx xx = akk * gm3 cll = (alf2 + xx) * st7 dll = (alf2 - xx) * st8 xx = akk * (one-gm3) fll = (alf1 + xx) * st8 ell = (alf1 - xx) * st7 st3 = max(abs(st7*st8),tumin) st3 = sign (st3,st7) st2 = expmn(-akk*taup) st4 = st2 * st2 st1 = sscp / ((akk+gm1 + (akk-gm1)*st4) * st3) c rr is r-hat of eq(21) of K & H c tt is diffuse part of t-hat of eq(22) of K & H rr = ( cll-dll*st4 -all*st2)*st1 tt = - ((fll-ell*st4)*td-bll*st2)*st1 rr = max(rr,zero) tt = max(tt,zero) return end c********************************************************************* subroutine sagpol(tau,ssc,g0,rll,tll) c********************************************************************* c-----transmittance (tll) and reflectance (rll) of diffuse radiation c follows Sagan and Pollock (JGR, 1967). c also, eq.(31) of Lacis and Hansen (JAS, 1974). c c-----input parameters: c c tau: the effective optical thickness c ssc: the effective single scattering albedo c g0: the effective asymmetry factor c c-----output parameters: c c rll: the layer reflection of diffuse radiation c tll: the layer transmission of diffuse radiation c c********************************************************************* implicit none c-----Explicit Inline Directives #ifdef CRAY #ifdef f77 cfpp$ expand (expmn) #endif #endif _RL expmn _RL one,three,four parameter (one=1., three=3., four=4.) c-----output parameters: _RL tau,ssc,g0 c-----output parameters: _RL rll,tll c-----temporary arrays _RL xx,uuu,ttt,emt,up1,um1,st1 xx = one-ssc*g0 uuu = sqrt( xx/(one-ssc)) ttt = sqrt( xx*(one-ssc)*three )*tau emt = expmn(-ttt) up1 = uuu + one um1 = uuu - one xx = um1*emt st1 = one / ((up1+xx) * (up1-xx)) rll = up1*um1*(one-emt*emt)*st1 tll = uuu*four*emt *st1 return end c******************************************************************* function expmn(fin) c******************************************************************* c compute exponential for arguments in the range 0> fin > -10. c******************************************************************* implicit none _RL fin,expmn _RL one,expmin,e1,e2,e3,e4 parameter (one=1.0, expmin=-10.0) parameter (e1=1.0, e2=-2.507213e-1) parameter (e3=2.92732e-2, e4=-3.827800e-3) if (fin .lt. expmin) fin = expmin expmn = ((e4*fin + e3)*fin+e2)*fin+e1 expmn = expmn * expmn expmn = one / (expmn * expmn) return end c******************************************************************* subroutine cldflx (m,n,np,ict,icb,cc,rr,tt,td,rs,ts, * fclr,fall,fsdir,fsdif) c******************************************************************* c compute upward and downward fluxes using a two-stream adding method c following equations (3)-(5) of Chou (1992, JAS). c c clouds are grouped into high, middle, and low clouds which are c assumed randomly overlapped. It involves eight sets of calculations. c In each set of calculations, each atmospheric layer is homogeneous, c either with clouds or without clouds. c input parameters: c m: number of soundings in zonal direction c n: number of soundings in meridional direction c np: number of atmospheric layers c ict: the level separating high and middle clouds c icb: the level separating middle and low clouds c cc: effective cloud covers for high, middle and low clouds c tt: diffuse transmission of a layer illuminated by beam radiation c td: direct beam tranmssion c ts: transmission of a layer illuminated by diffuse radiation c rr: reflection of a layer illuminated by beam radiation c rs: reflection of a layer illuminated by diffuse radiation c c output parameters: c fclr: clear-sky flux (downward minus upward) c fall: all-sky flux (downward minus upward) c fdndir: surface direct downward flux c fdndif: surface diffuse downward flux c*********************************************************************c implicit none c-----input parameters integer m,n,np,ict,icb _RL rr(m,n,np+1,2),tt(m,n,np+1,2),td(m,n,np+1,2) _RL rs(m,n,np+1,2),ts(m,n,np+1,2) _RL cc(m,n,3) c-----temporary array integer i,j,k,ih,im,is _RL rra(m,n,np+1,2,2),tta(m,n,np+1,2,2),tda(m,n,np+1,2,2) _RL rsa(m,n,np+1,2,2),rxa(m,n,np+1,2,2) _RL ch(m,n),cm(m,n),ct(m,n),flxdn(m,n,np+1) _RL fdndir(m,n),fdndif(m,n),fupdif _RL denm,xx c-----output parameters _RL fclr(m,n,np+1),fall(m,n,np+1) _RL fsdir(m,n),fsdif(m,n) c-----initialize all-sky flux (fall) and surface downward fluxes do k=1,np+1 do j=1,n do i=1,m fall(i,j,k)=0.0 enddo enddo enddo do j=1,n do i=1,m fsdir(i,j)=0.0 fsdif(i,j)=0.0 enddo enddo c-----compute transmittances and reflectances for a composite of c layers. layers are added one at a time, going down from the top. c tda is the composite transmittance illuminated by beam radiation c tta is the composite diffuse transmittance illuminated by c beam radiation c rsa is the composite reflectance illuminated from below c by diffuse radiation c tta and rsa are computed from eqs. (4b) and (3b) of Chou c-----for high clouds. indices 1 and 2 denote clear and cloudy c situations, respectively. do 10 ih=1,2 do j= 1, n do i= 1, m tda(i,j,1,ih,1)=td(i,j,1,ih) tta(i,j,1,ih,1)=tt(i,j,1,ih) rsa(i,j,1,ih,1)=rs(i,j,1,ih) tda(i,j,1,ih,2)=td(i,j,1,ih) tta(i,j,1,ih,2)=tt(i,j,1,ih) rsa(i,j,1,ih,2)=rs(i,j,1,ih) enddo enddo do k= 2, ict-1 do j= 1, n do i= 1, m denm = ts(i,j,k,ih)/( 1.-rsa(i,j,k-1,ih,1)*rs(i,j,k,ih)) tda(i,j,k,ih,1)= tda(i,j,k-1,ih,1)*td(i,j,k,ih) tta(i,j,k,ih,1)= tda(i,j,k-1,ih,1)*tt(i,j,k,ih) * +(tda(i,j,k-1,ih,1)*rr(i,j,k,ih) * *rsa(i,j,k-1,ih,1)+tta(i,j,k-1,ih,1))*denm rsa(i,j,k,ih,1)= rs(i,j,k,ih)+ts(i,j,k,ih) * *rsa(i,j,k-1,ih,1)*denm tda(i,j,k,ih,2)= tda(i,j,k,ih,1) tta(i,j,k,ih,2)= tta(i,j,k,ih,1) rsa(i,j,k,ih,2)= rsa(i,j,k,ih,1) enddo enddo enddo c-----for middle clouds do 10 im=1,2 do k= ict, icb-1 do j= 1, n do i= 1, m denm = ts(i,j,k,im)/( 1.-rsa(i,j,k-1,ih,im)*rs(i,j,k,im)) tda(i,j,k,ih,im)= tda(i,j,k-1,ih,im)*td(i,j,k,im) tta(i,j,k,ih,im)= tda(i,j,k-1,ih,im)*tt(i,j,k,im) * +(tda(i,j,k-1,ih,im)*rr(i,j,k,im) * *rsa(i,j,k-1,ih,im)+tta(i,j,k-1,ih,im))*denm rsa(i,j,k,ih,im)= rs(i,j,k,im)+ts(i,j,k,im) * *rsa(i,j,k-1,ih,im)*denm enddo enddo enddo 10 continue c-----layers are added one at a time, going up from the surface. c rra is the composite reflectance illuminated by beam radiation c rxa is the composite reflectance illuminated from above c by diffuse radiation c rra and rxa are computed from eqs. (4a) and (3a) of Chou c-----for the low clouds do 20 is=1,2 do j= 1, n do i= 1, m rra(i,j,np+1,1,is)=rr(i,j,np+1,is) rxa(i,j,np+1,1,is)=rs(i,j,np+1,is) rra(i,j,np+1,2,is)=rr(i,j,np+1,is) rxa(i,j,np+1,2,is)=rs(i,j,np+1,is) enddo enddo do k=np,icb,-1 do j= 1, n do i= 1, m denm=ts(i,j,k,is)/( 1.-rs(i,j,k,is)*rxa(i,j,k+1,1,is) ) rra(i,j,k,1,is)=rr(i,j,k,is)+(td(i,j,k,is) * *rra(i,j,k+1,1,is)+tt(i,j,k,is)*rxa(i,j,k+1,1,is))*denm rxa(i,j,k,1,is)= rs(i,j,k,is)+ts(i,j,k,is) * *rxa(i,j,k+1,1,is)*denm rra(i,j,k,2,is)=rra(i,j,k,1,is) rxa(i,j,k,2,is)=rxa(i,j,k,1,is) enddo enddo enddo c-----for middle clouds do 20 im=1,2 do k= icb-1,ict,-1 do j= 1, n do i= 1, m denm=ts(i,j,k,im)/( 1.-rs(i,j,k,im)*rxa(i,j,k+1,im,is) ) rra(i,j,k,im,is)= rr(i,j,k,im)+(td(i,j,k,im) * *rra(i,j,k+1,im,is)+tt(i,j,k,im)*rxa(i,j,k+1,im,is))*denm rxa(i,j,k,im,is)= rs(i,j,k,im)+ts(i,j,k,im) * *rxa(i,j,k+1,im,is)*denm enddo enddo enddo 20 continue c-----integration over eight sky situations. c ih, im, is denotes high, middle and low cloud groups. do 100 ih=1,2 c-----clear portion if(ih.eq.1) then do j=1,n do i=1,m ch(i,j)=1.0-cc(i,j,1) enddo enddo else c-----cloudy portion do j=1,n do i=1,m ch(i,j)=cc(i,j,1) enddo enddo endif do 100 im=1,2 c-----clear portion if(im.eq.1) then do j=1,n do i=1,m cm(i,j)=ch(i,j)*(1.0-cc(i,j,2)) enddo enddo else c-----cloudy portion do j=1,n do i=1,m cm(i,j)=ch(i,j)*cc(i,j,2) enddo enddo endif do 100 is=1,2 c-----clear portion if(is.eq.1) then do j=1,n do i=1,m ct(i,j)=cm(i,j)*(1.0-cc(i,j,3)) enddo enddo else c-----cloudy portion do j=1,n do i=1,m ct(i,j)=cm(i,j)*cc(i,j,3) enddo enddo endif c-----add one layer at a time, going down. do k= icb, np do j= 1, n do i= 1, m denm = ts(i,j,k,is)/( 1.-rsa(i,j,k-1,ih,im)*rs(i,j,k,is) ) tda(i,j,k,ih,im)= tda(i,j,k-1,ih,im)*td(i,j,k,is) tta(i,j,k,ih,im)= tda(i,j,k-1,ih,im)*tt(i,j,k,is) * +(tda(i,j,k-1,ih,im)*rr(i,j,k,is) * *rsa(i,j,k-1,ih,im)+tta(i,j,k-1,ih,im))*denm rsa(i,j,k,ih,im)= rs(i,j,k,is)+ts(i,j,k,is) * *rsa(i,j,k-1,ih,im)*denm enddo enddo enddo c-----add one layer at a time, going up. do k= ict-1,1,-1 do j= 1, n do i= 1, m denm =ts(i,j,k,ih)/(1.-rs(i,j,k,ih)*rxa(i,j,k+1,im,is)) rra(i,j,k,im,is)= rr(i,j,k,ih)+(td(i,j,k,ih) * *rra(i,j,k+1,im,is)+tt(i,j,k,ih)*rxa(i,j,k+1,im,is))*denm rxa(i,j,k,im,is)= rs(i,j,k,ih)+ts(i,j,k,ih) * *rxa(i,j,k+1,im,is)*denm enddo enddo enddo c-----compute fluxes following eq (5) of Chou (1992) c fdndir is the direct downward flux c fdndif is the diffuse downward flux c fupdif is the diffuse upward flux do k=2,np+1 do j=1, n do i=1, m denm= 1./(1.- rxa(i,j,k,im,is)*rsa(i,j,k-1,ih,im)) fdndir(i,j)= tda(i,j,k-1,ih,im) xx = tda(i,j,k-1,ih,im)*rra(i,j,k,im,is) fdndif(i,j)= (xx*rsa(i,j,k-1,ih,im)+tta(i,j,k-1,ih,im))*denm fupdif= (xx+tta(i,j,k-1,ih,im)*rxa(i,j,k,im,is))*denm flxdn(i,j,k)=fdndir(i,j)+fdndif(i,j)-fupdif enddo enddo enddo do j=1, n do i=1, m flxdn(i,j,1)=1.0-rra(i,j,1,im,is) enddo enddo c-----summation of fluxes over all (eight) sky situations. do k=1,np+1 do j=1,n do i=1,m if(ih.eq.1 .and. im.eq.1 .and. is.eq.1) then fclr(i,j,k)=flxdn(i,j,k) endif fall(i,j,k)=fall(i,j,k)+flxdn(i,j,k)*ct(i,j) enddo enddo enddo do j=1,n do i=1,m fsdir(i,j)=fsdir(i,j)+fdndir(i,j)*ct(i,j) fsdif(i,j)=fsdif(i,j)+fdndif(i,j)*ct(i,j) enddo enddo 100 continue return end c***************************************************************** subroutine flxco2(m,n,np,swc,swh,csm,df) c***************************************************************** c-----compute the reduction of clear-sky downward solar flux c due to co2 absorption. implicit none c-----input parameters integer m,n,np _RL csm(m,n),swc(m,n,np+1),swh(m,n,np+1),cah(22,19) c-----output (undated) parameter _RL df(m,n,np+1) c-----temporary array integer i,j,k,ic,iw _RL xx,clog,wlog,dc,dw,x1,x2,y2 c******************************************************************** c-----include co2 look-up table #include "cah-dat.h" c save cah c******************************************************************** c-----table look-up for the reduction of clear-sky solar c radiation due to co2. The fraction 0.0343 is the c extraterrestrial solar flux in the co2 bands. do k= 2, np+1 do j= 1, n do i= 1, m xx=1./.3 clog=log10(swc(i,j,k)*csm(i,j)) wlog=log10(swh(i,j,k)*csm(i,j)) ic=int( (clog+3.15)*xx+1.) iw=int( (wlog+4.15)*xx+1.) if(ic.lt.2)ic=2 if(iw.lt.2)iw=2 if(ic.gt.22)ic=22 if(iw.gt.19)iw=19 dc=clog-float(ic-2)*.3+3. dw=wlog-float(iw-2)*.3+4. x1=cah(1,iw-1)+(cah(1,iw)-cah(1,iw-1))*xx*dw x2=cah(ic-1,iw-1)+(cah(ic-1,iw)-cah(ic-1,iw-1))*xx*dw y2=x2+(cah(ic,iw-1)-cah(ic-1,iw-1))*xx*dc if (x1.lt.y2) x1=y2 df(i,j,k)=df(i,j,k)+0.0343*(x1-y2) enddo enddo enddo return end