!
!
!##################################################################
!##################################################################
!###### ######
!###### SUBROUTINE IRRAD ######
!###### ######
!###### Developed by ######
!###### ######
!###### Goddard Cumulus Ensemble Modeling Group, NASA ######
!###### ######
!###### Center for Analysis and Prediction of Storms ######
!###### University of Oklahoma ######
!###### ######
!##################################################################
!##################################################################
!
SUBROUTINE irrad(idim,jdim,m,n,np, & 1,13
taucl,ccld,pl,ta,wa,oa,co2,ts, &
high,flx,flc,dfdts,st4, &
fclr,dbs,trant,th2o,tcon,tco2, &
pa,dt,sh2o,swpre,swtem,sco3,scopre,scotem, &
dh2o,dcont,dco2,do3,flxu,flxd,clr,blayer, &
h2oexp,conexp,co2exp)
!
!-----------------------------------------------------------------------
!
! PURPOSE:
!
! Calculate IR fluxes due to water vapor, co2, and o3. Clouds in
! different layers are assumed randomly overlapped.
!
!-----------------------------------------------------------------------
!
! AUTHOR: (a) Radiative Transfer Model: M.-D. Chou and M. Suarez
! (b) Cloud Optics:Tao, Lang, Simpson, Sui, Ferrier and
! Chou (1996)
!
! MODIFICATION HISTORY:
!
! 03/15/1996 (Yuhe Liu)
! Adopted the original code and formatted it in accordance with the
! ARPS coding standard.
!
!-----------------------------------------------------------------------
!
! ORIGINAL COMMENTS:
!
!******************** CLIRAD IR1 Date: Oct. 17, 1994 ****************
!*********************************************************************
!
! This routine computes ir fluxes due to water vapor, co2, and o3.
! Clouds in different layers are assumed randomly overlapped.
!
! This is a vectorized code. It computes fluxes simultaneously for
! (m x n) soundings, which is a subset of (m x ndim) soundings.
! In a global climate model, m and ndim correspond to the numbers of
! grid boxes in the zonal and meridional directions, respectively.
!
! Detailed description of the radiation routine is given in
! Chou and Suarez (1994).
!
! There are two options for computing cooling rate profiles.
!
! if high = .true., transmission functions in the co2, o3, and the
! three water vapor bands with strong absorption are computed using
! table look-up. cooling rates are computed accurately from the
! surface up to 0.01 mb.
! if high = .false., transmission functions are computed using the
! k-distribution method with linear pressure scaling. cooling rates
! are not calculated accurately for pressures less than 20 mb.
! the computation is faster with high=.false. than with high=.true.
!
! The IR spectrum is divided into eight bands:
!
! bnad wavenumber (/cm) absorber method
!
! 1 0 - 340 h2o K/T
! 2 340 - 540 h2o K/T
! 3 540 - 800 h2o,cont,co2 K,S,K/T
! 4 800 - 980 h2o,cont K,S
! 5 980 - 1100 h2o,cont,o3 K,S,T
! 6 1100 - 1380 h2o,cont K,S
! 7 1380 - 1900 h2o K/T
! 8 1900 - 3000 h2o K
!
! Note : "h2o" for h2o line absorption
! "cont" for h2o continuum absorption
! "K" for k-distribution method
! "S" for one-parameter temperature scaling
! "T" for table look-up
!
! The 15 micrometer region (540-800/cm) is further divided into
! 3 sub-bands :
!
! subbnad wavenumber (/cm)
!
! 1 540 - 620
! 2 620 - 720
! 3 720 - 800
!
!---- Input parameters units size
!
! number of soundings in zonal direction (m) n/d 1
! number of soundings in meridional direction (n) n/d 1
! maximum number of soundings in
! meridional direction (ndim) n/d 1
! number of atmospheric layers (np) n/d 1
! cloud optical thickness (taucl) n/d m*ndim*np
! cloud cover (ccld) fraction m*ndim*np
! level pressure (pl) mb m*ndim*(np+1)
! layer temperature (ta) k m*ndim*np
! layer specific humidity (wa) g/g m*ndim*np
! layer ozone mixing ratio by mass (oa) g/g m*ndim*np
! surface temperature (ts) k m*ndim
! co2 mixing ratio by volumn (co2) pppv 1
! high 1
!
! pre-computed tables used in table look-up for transmittance calculations:
!
! c1 , c2, c3: for co2 (band 3)
! o1 , o2, o3: for o3 (band 5)
! h11,h12,h13: for h2o (band 1)
! h21,h22,h23: for h2o (band 2)
! h71,h72,h73: for h2o (band 7)
!
!---- output parameters
!
! net downward flux, all-sky (flx) w/m**2 m*ndim*(np+1)
! net downward flux, clear-sky (flc) w/m**2 m*ndim*(np+1)
! sensitivity of net downward flux
! to surface temperature (dfdts) w/m**2/k m*ndim*(np+1)
! emission by the surface (st4) w/m**2 m*ndim
!
! Notes:
!
! (1) Water vapor continuum absorption is included in 540-1380 /cm.
! (2) Scattering by clouds is not included.
! (3) Clouds are assumed "gray" bodies.
! (4) The diffuse cloud transmission is computed to be exp(-1.66*taucl).
! (5) If there are no clouds, flx=flc.
! (6) plevel(1) is the pressure at the top of the model atmosphere, and
! plevel(np+1) is the surface pressure.
!
! ARPS note: pl was replaced by pa at scalar points (layers)
!
! (7) Downward flux is positive, and upward flux is negative.
! (8) dfdts is always negative because upward flux is defined as negative.
! (9) For questions and coding errors, please contact with Ming-Dah Chou,
! Code 913, NASA/Goddard Space Flight Center, Greenbelt, MD 20771.
! Phone: 301-286-4012, Fax: 301-286-1759,
! e-mail: chou@climate.gsfc.nasa.gov
!
!-----parameters defining the size of the pre-computed tables for transmittance
! calculations using table look-up.
!
! "nx" is the number of intervals in pressure
! "no" is the number of intervals in o3 amount
! "nc" is the number of intervals in co2 amount
! "nh" is the number of intervals in h2o amount
! "nt" is the number of copies to be made from the pre-computed
! transmittance tables to reduce "memory-bank conflict"
! in parallel machines and, hence, enhancing the speed of
! computations using table look-up.
! If such advantage does not exist, "nt" can be set to 1.
!***************************************************************************
!
!fpp$ expand (expmn)
!dir$ inline always expmn
!*$* inline routine (expmn)
!
!-----------------------------------------------------------------------
!
!
!-----------------------------------------------------------------------
!
! Variable Declarations.
!
!-----------------------------------------------------------------------
!
IMPLICIT NONE
INTEGER :: idim,jdim
INTEGER :: nx,no,nc,nh,nt,m,n,np
INTEGER :: i,j,k,ip,iw,it,ib,ik,iq,isb,k1,k2
PARAMETER (nx=26,no=21,nc=24,nh=31,nt=7)
!---- input parameters ------
REAL :: taucl(idim,jdim,np)
REAL :: ccld(idim,jdim,np)
REAL :: pl(idim,jdim,np+1)
REAL :: ta(idim,jdim,np)
REAL :: wa(idim,jdim,np)
REAL :: oa(idim,jdim,np)
REAL :: ts(idim,jdim)
REAL :: co2
LOGICAL :: high
!---- output parameters ------
REAL :: flx(idim,jdim,np+1)
REAL :: flc(idim,jdim,np+1)
REAL :: dfdts(idim,jdim,np+1)
REAL :: st4(idim,jdim)
!
!-----------------------------------------------------------------------
!
! Temporary arrays
!
!-----------------------------------------------------------------------
!
REAL :: fclr(m,n)
REAL :: dbs(m,n)
REAL :: trant(m,n)
REAL :: th2o(m,n,6)
REAL :: tcon(m,n,3)
REAL :: tco2(m,n,6,2)
REAL :: pa(m,n,np)
REAL :: dt(m,n,np)
REAL :: sh2o(m,n,np+1)
REAL :: swpre(m,n,np+1)
REAL :: swtem(m,n,np+1)
REAL :: sco3(m,n,np+1)
REAL :: scopre(m,n,np+1)
REAL :: scotem(m,n,np+1)
REAL :: dh2o(m,n,np)
REAL :: dcont(m,n,np)
REAL :: dco2(m,n,np)
REAL :: do3(m,n,np)
REAL :: flxu(m,n,np+1)
REAL :: flxd(m,n,np+1)
REAL :: clr(m,n,0:np+1)
REAL :: blayer(m,n,0:np+1)
REAL :: h2oexp(m,n,np,6)
REAL :: conexp(m,n,np,3)
REAL :: co2exp(m,n,np,6,2)
!
!-----------------------------------------------------------------------
!
! Misc. local variables
!
!-----------------------------------------------------------------------
!
LOGICAL :: oznbnd
LOGICAL :: co2bnd
LOGICAL :: h2otbl
LOGICAL :: conbnd
REAL :: c1 (nx,nc,nt),c2 (nx,nc,nt),c3 (nx,nc,nt)
REAL :: o1 (nx,no,nt),o2 (nx,no,nt),o3 (nx,no,nt)
REAL :: h11(nx,nh,nt),h12(nx,nh,nt),h13(nx,nh,nt)
REAL :: h21(nx,nh,nt),h22(nx,nh,nt),h23(nx,nh,nt)
REAL :: h71(nx,nh,nt),h72(nx,nh,nt),h73(nx,nh,nt)
REAL :: xx, w1,p1,dwe,dpe
!---- static data -----
REAL :: cb(5,8)
!-----the following coefficients (table 2 of chou and suarez, 1995)
! are for computing spectrally integtrated planck fluxes of
! the 8 bands using eq. (22)
DATA cb/ &
-2.6844E-1,-8.8994E-2, 1.5676E-3,-2.9349E-6, 2.2233E-9, &
3.7315E+1,-7.4758E-1, 4.6151E-3,-6.3260E-6, 3.5647E-9, &
3.7187E+1,-3.9085E-1,-6.1072E-4, 1.4534E-5,-1.6863E-8, &
-4.1928E+1, 1.0027E+0,-8.5789E-3, 2.9199E-5,-2.5654E-8, &
-4.9163E+1, 9.8457E-1,-7.0968E-3, 2.0478E-5,-1.5514E-8, &
-1.0345E+2, 1.8636E+0,-1.1753E-2, 2.7864E-5,-1.1998E-8, &
-6.9233E+0,-1.5878E-1, 3.9160E-3,-2.4496E-5, 4.9301E-8, &
1.1483E+2,-2.2376E+0, 1.6394E-2,-5.3672E-5, 6.6456E-8/
!-----copy tables to enhance the speed of co2 (band 3), o3 (band5),
! and h2o (bands 1, 2, and 7 only) transmission calculations
! using table look-up.
LOGICAL :: first
SAVE first
DATA first /.true./
!
!-----------------------------------------------------------------------
!
! Functions:
!
!-----------------------------------------------------------------------
!
REAL :: expmn
!
!-----------------------------------------------------------------------
!
! Include files:
!
!-----------------------------------------------------------------------
!
! include "h2o.tran3"
! include "co2.tran3"
! include "o3.tran3"
COMMON /radtab001/ h11,h12,h13,h21,h22,h23,h71,h72,h73
COMMON /radtab002/ c1,c2,c3
COMMON /radtab003/ o1,o2,o3
!
!-----------------------------------------------------------------------
!
! Save variables:
!
!-----------------------------------------------------------------------
!
! save c1,c2,c3,o1,o2,o3
! save h11,h12,h13,h21,h22,h23,h71,h72,h73
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
! Beginning of executable code...
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
IF (first) THEN
!-----tables co2 and h2o are only used with 'high' option
IF (high) THEN
DO iw=1,nh
DO ip=1,nx
h11(ip,iw,1)=1.0-h11(ip,iw,1)
h21(ip,iw,1)=1.0-h21(ip,iw,1)
h71(ip,iw,1)=1.0-h71(ip,iw,1)
END DO
END DO
DO iw=1,nc
DO ip=1,nx
c1(ip,iw,1)=1.0-c1(ip,iw,1)
END DO
END DO
!-----tables are replicated to avoid memory bank conflicts
DO it=2,nt
DO iw=1,nc
DO ip=1,nx
c1 (ip,iw,it)= c1(ip,iw,1)
c2 (ip,iw,it)= c2(ip,iw,1)
c3 (ip,iw,it)= c3(ip,iw,1)
END DO
END DO
DO iw=1,nh
DO ip=1,nx
h11(ip,iw,it)=h11(ip,iw,1)
h12(ip,iw,it)=h12(ip,iw,1)
h13(ip,iw,it)=h13(ip,iw,1)
h21(ip,iw,it)=h21(ip,iw,1)
h22(ip,iw,it)=h22(ip,iw,1)
h23(ip,iw,it)=h23(ip,iw,1)
h71(ip,iw,it)=h71(ip,iw,1)
h72(ip,iw,it)=h72(ip,iw,1)
h73(ip,iw,it)=h73(ip,iw,1)
END DO
END DO
END DO
END IF
!-----always use table look-up for ozone transmittance
DO iw=1,no
DO ip=1,nx
o1(ip,iw,1)=1.0-o1(ip,iw,1)
END DO
END DO
DO it=2,nt
DO iw=1,no
DO ip=1,nx
o1 (ip,iw,it)= o1(ip,iw,1)
o2 (ip,iw,it)= o2(ip,iw,1)
o3 (ip,iw,it)= o3(ip,iw,1)
END DO
END DO
END DO
first=.false.
END IF
!-----compute layer pressure (pa) and layer temperature minus 250K (dt)
DO k=1,np
DO j=1,n
DO i=1,m
dt(i,j,k)=ta(i,j,k)-250.0
pa(i,j,k)=0.5*(pl(i,j,k)+pl(i,j,k+1))
END DO
END DO
END DO
!-----compute layer absorber amount
! dh2o : water vapor amount (g/cm**2)
! dcont: scaled water vapor amount for continuum absorption (g/cm**2)
! dco2 : co2 amount (cm-atm)stp
! do3 : o3 amount (cm-atm)stp
! the factor 1.02 is equal to 1000/980
! factors 789 and 476 are for unit conversion
! the factor 0.001618 is equal to 1.02/(.622*1013.25)
! the factor 6.081 is equal to 1800/296
DO k=1,np
DO j=1,n
DO i=1,m
dh2o(i,j,k) = 1.02*wa(i,j,k)*(pl(i,j,k+1)-pl(i,j,k))+1.e-10
dco2(i,j,k) = 789.*co2*(pl(i,j,k+1)-pl(i,j,k))+1.e-10
do3 (i,j,k) = 476.0*oa(i,j,k)*(pl(i,j,k+1)-pl(i,j,k))+1.e-10
!-----compute scaled water vapor amount for h2o continuum absorption
! following eq. (43).
xx=pa(i,j,k)*0.001618*wa(i,j,k)*wa(i,j,k) &
*(pl(i,j,k+1)-pl(i,j,k))
dcont(i,j,k) = xx*expmn(1800./ta(i,j,k)-6.081)+1.e-10
!-----compute effective cloud-free fraction, clr, for each layer.
! the cloud diffuse transmittance is approximated by using a
! diffusivity factor of 1.66.
clr(i,j,k)=1.0-(ccld(i,j,k)*(1.-expmn(-1.66*taucl(i,j,k))))
END DO
END DO
END DO
!-----compute column-integrated h2o amoumt, h2o-weighted pressure
! and temperature. it follows eqs. (37) and (38).
IF (high) THEN
CALL column
(m,n,np,pa,dt,dh2o,sh2o,swpre,swtem)
END IF
!-----the surface (with an index np+1) is treated as a layer filled with
! black clouds.
DO j=1,n
DO i=1,m
clr(i,j,0) = 1.0
clr(i,j,np+1) = 0.0
st4(i,j) = 0.0
END DO
END DO
!-----initialize fluxes
DO k=1,np+1
DO j=1,n
DO i=1,m
flx(i,j,k) = 0.0
flc(i,j,k) = 0.0
dfdts(i,j,k)= 0.0
flxu(i,j,k) = 0.0
flxd(i,j,k) = 0.0
END DO
END DO
END DO
!-----integration over spectral bands
DO ib=1,8
!-----if h2otbl, compute h2o (line) transmittance using table look-up.
! if conbnd, compute h2o (continuum) transmittance in bands 3, 4, 5 and 6.
! if co2bnd, compute co2 transmittance in band 3.
! if oznbnd, compute o3 transmittance in band 5.
h2otbl=high.AND.(ib == 1.OR.ib == 2.OR.ib == 7)
conbnd=ib >= 3.AND.ib <= 6
co2bnd=ib == 3
oznbnd=ib == 5
!-----blayer is the spectrally integrated planck flux of the mean layer
! temperature derived from eq. (22)
! the fitting for the planck flux is valid in the range 160-345 K.
DO k=1,np
DO j=1,n
DO i=1,m
blayer(i,j,k)=ta(i,j,k)*(ta(i,j,k)*(ta(i,j,k) &
*(ta(i,j,k)*cb(5,ib)+cb(4,ib))+cb(3,ib)) &
+cb(2,ib))+cb(1,ib)
END DO
END DO
END DO
!-----the earth's surface, with an index "np+1", is treated as a layer
DO j=1,n
DO i=1,m
blayer(i,j,0) = 0.0
blayer(i,j,np+1)=ts(i,j)*(ts(i,j)*(ts(i,j) &
*(ts(i,j)*cb(5,ib)+cb(4,ib))+cb(3,ib)) &
+cb(2,ib))+cb(1,ib)
!-----dbs is the derivative of the surface planck flux with respect to
! surface temperature (eq. 59).
dbs(i,j)=ts(i,j)*(ts(i,j)*(ts(i,j) &
*4.*cb(5,ib)+3.*cb(4,ib))+2.*cb(3,ib))+cb(2,ib)
END DO
END DO
!-----compute column-integrated absorber amoumt, absorber-weighted
! pressure and temperature for co2 (band 3) and o3 (band 5).
! it follows eqs. (37) and (38).
!-----this is in the band loop to save storage
IF( high .AND. co2bnd) THEN
CALL column(m,n,np,pa,dt,dco2,sco3,scopre,scotem)
END IF
IF(oznbnd) THEN
CALL column(m,n,np,pa,dt,do3,sco3,scopre,scotem)
END IF
!-----compute the exponential terms (eq. 32) at each layer for
! water vapor line absorption when k-distribution is used
IF( .NOT. h2otbl) THEN
CALL h2oexps(ib,m,n,np,dh2o,pa,dt,h2oexp)
END IF
!-----compute the exponential terms (eq. 46) at each layer for
! water vapor continuum absorption
IF( conbnd) THEN
CALL conexps(ib,m,n,np,dcont,conexp)
END IF
!-----compute the exponential terms (eq. 32) at each layer for
! co2 absorption
IF( .NOT.high .AND. co2bnd) THEN
CALL co2exps(m,n,np,dco2,pa,dt,co2exp)
END IF
!-----compute transmittances for regions between levels k1 and k2
! and update the fluxes at the two levels.
DO k1=1,np
!-----initialize fclr, th2o, tcon, and tco2
DO j=1,n
DO i=1,m
fclr(i,j)=1.0
END DO
END DO
!-----for h2o line absorption
IF(.NOT. h2otbl) THEN
DO ik=1,6
DO j=1,n
DO i=1,m
th2o(i,j,ik)=1.0
END DO
END DO
END DO
END IF
!-----for h2o continuum absorption
IF (conbnd) THEN
DO iq=1,3
DO j=1,n
DO i=1,m
tcon(i,j,iq)=1.0
END DO
END DO
END DO
END IF
!-----for co2 absorption when using k-distribution method.
! band 3 is divided into 3 sub-bands, but sub-bands 3a and 3c
! are combined in computing the co2 transmittance.
IF (.NOT. high .AND. co2bnd) THEN
DO isb=1,2
DO ik=1,6
DO j=1,n
DO i=1,m
tco2(i,j,ik,isb)=1.0
END DO
END DO
END DO
END DO
END IF
!-----loop over the bottom level of the region (k2)
DO k2=k1+1,np+1
DO j=1,n
DO i=1,m
trant(i,j)=1.0
END DO
END DO
IF(h2otbl) THEN
w1=-8.0
p1=-2.0
dwe=0.3
dpe=0.2
!-----compute water vapor transmittance using table look-up
IF (ib == 1 ) THEN
CALL tablup(k1,k2,m,n,np,nx,nh,nt,sh2o,swpre,swtem, &
w1,p1,dwe,dpe,h11,h12,h13,trant)
END IF
IF (ib == 2 ) THEN
CALL tablup(k1,k2,m,n,np,nx,nh,nt,sh2o,swpre,swtem, &
w1,p1,dwe,dpe,h21,h22,h23,trant)
END IF
IF (ib == 7 ) THEN
CALL tablup(k1,k2,m,n,np,nx,nh,nt,sh2o,swpre,swtem, &
w1,p1,dwe,dpe,h71,h72,h73,trant)
END IF
ELSE
!-----compute water vapor transmittance using k-distribution.
CALL wvkdis(ib,m,n,np,k2-1,h2oexp,conexp,th2o,tcon,trant)
END IF
IF(co2bnd) THEN
IF( high ) THEN
!-----compute co2 transmittance using table look-up method
w1=-4.0
p1=-2.0
dwe=0.3
dpe=0.2
CALL tablup(k1,k2,m,n,np,nx,nc,nt,sco3,scopre,scotem, &
w1,p1,dwe,dpe,c1,c2,c3,trant)
ELSE
!-----compute co2 transmittance using k-distribution method
CALL co2kdis(m,n,np,k2-1,co2exp,tco2,trant)
END IF
END IF
!-----compute o3 transmittance using table look-up
IF (oznbnd) THEN
w1=-6.0
p1=-2.0
dwe=0.3
dpe=0.2
CALL tablup(k1,k2,m,n,np,nx,no,nt,sco3,scopre,scotem, &
w1,p1,dwe,dpe,o1,o2,o3,trant)
END IF
!-----fclr is the clear line-of-sight between levels k1 and k2.
! in computing fclr, clouds are assumed randomly overlapped
! using eq. (10).
DO j=1,n
DO i=1,m
fclr(i,j) = fclr(i,j)*clr(i,j,k2-1)
END DO
END DO
!-----compute upward and downward fluxes
!-----add "boundary" terms to the net downward flux.
! these are the first terms on the right-hand-side of
! eqs. (56a) and (56b).
! downward fluxes are positive.
IF (k2 == k1+1) THEN
DO j=1,n
DO i=1,m
flc(i,j,k1)=flc(i,j,k1)-blayer(i,j,k1)
flc(i,j,k2)=flc(i,j,k2)+blayer(i,j,k1)
END DO
END DO
END IF
!-----add flux components involving the four layers above and below
! the levels k1 and k2. it follows eqs. (56a) and (56b).
DO j=1,n
DO i=1,m
xx=trant(i,j)*(blayer(i,j,k2-1)-blayer(i,j,k2))
flc(i,j,k1) =flc(i,j,k1)+xx
xx=trant(i,j)*(blayer(i,j,k1-1)-blayer(i,j,k1))
flc(i,j,k2) =flc(i,j,k2)+xx
END DO
END DO
!-----compute upward and downward fluxes for all-sky situation
IF (k2 == k1+1) THEN
DO j=1,n
DO i=1,m
flxu(i,j,k1)=flxu(i,j,k1)-blayer(i,j,k1)
flxd(i,j,k2)=flxd(i,j,k2)+blayer(i,j,k1)
END DO
END DO
END IF
DO j=1,n
DO i=1,m
xx=trant(i,j)*(blayer(i,j,k2-1)-blayer(i,j,k2))
flxu(i,j,k1) =flxu(i,j,k1)+xx*fclr(i,j)
xx=trant(i,j)*(blayer(i,j,k1-1)-blayer(i,j,k1))
flxd(i,j,k2) =flxd(i,j,k2)+xx*fclr(i,j)
END DO
END DO
END DO
!-----compute the partial derivative of fluxes with respect to
! surface temperature (eq. 59).
DO j=1,n
DO i=1,m
dfdts(i,j,k1) =dfdts(i,j,k1)-dbs(i,j)*trant(i,j)*fclr(i,j)
END DO
END DO
END DO
!-----add contribution from the surface to the flux terms at the surface.
DO j=1,n
DO i=1,m
dfdts(i,j,np+1) =dfdts(i,j,np+1)-dbs(i,j)
END DO
END DO
DO j=1,n
DO i=1,m
flc(i,j,np+1)=flc(i,j,np+1)-blayer(i,j,np+1)
flxu(i,j,np+1)=flxu(i,j,np+1)-blayer(i,j,np+1)
st4(i,j)=st4(i,j)-blayer(i,j,np+1)
END DO
END DO
! write(7,3211) ib, flxd(1,1,52),flxu(1,1,52)
! write(7,3211) ib, flxd(1,1,np+1),flxu(1,1,np+1)
! 3211 FORMAT ('ib, fluxd, fluxu=', i3,2F12.3)
END DO
DO k=1,np+1
DO j=1,n
DO i=1,m
flx(i,j,k)=flxd(i,j,k)+flxu(i,j,k)
END DO
END DO
END DO
RETURN
END SUBROUTINE irrad
!
!
!##################################################################
!##################################################################
!###### ######
!###### SUBROUTINE H2OEXPS ######
!###### ######
!###### Developed by ######
!###### ######
!###### Goddard Cumulus Ensemble Modeling Group, NASA ######
!###### ######
!###### Center for Analysis and Prediction of Storms ######
!###### University of Oklahoma ######
!###### ######
!##################################################################
!##################################################################
!
SUBROUTINE h2oexps(ib,m,n,np,dh2o,pa,dt,h2oexp) 1
!
!-----------------------------------------------------------------------
!
! PURPOSE:
!
! Calculate exponentials for water vapor line absorption in
! individual layers.
!
!-----------------------------------------------------------------------
!
!
! AUTHOR: (a) Radiative Transfer Model: M.-D. Chou and M. Suarez
! (b) Cloud Optics:Tao, Lang, Simpson, Sui, Ferrier and
! Chou (1996)
!
! MODIFICATION:
!
! 03/11/1996 (Yuhe Liu)
! Formatted code to ARPS standard format
!
!-----------------------------------------------------------------------
!
! ORIGINAL COMMENTS:
!
! compute exponentials for water vapor line absorption
! in individual layers.
!
!---- input parameters
! spectral band (ib)
! number of grid intervals in zonal direction (m)
! number of grid intervals in meridional direction (n)
! number of layers (np)
! layer water vapor amount for line absorption (dh2o)
! layer pressure (pa)
! layer temperature minus 250K (dt)
!
!---- output parameters
! 6 exponentials for each layer (h2oexp)
!
!**********************************************************************
!
!fpp$ expand (expmn)
!dir$ inline always expmn
!*$* inline routine (expmn)
!
!-----------------------------------------------------------------------
!
! Variable declarations
!
!-----------------------------------------------------------------------
!
IMPLICIT NONE
INTEGER :: ib,m,n,np
!---- input parameters ------
REAL :: dh2o(m,n,np)
REAL :: pa(m,n,np)
REAL :: dt(m,n,np)
!---- output parameters -----
REAL :: h2oexp(m,n,np,6)
!---- static data -----
INTEGER :: mw(8)
REAL :: xkw(8)
REAL :: aw(8)
REAL :: bw(8)
!---- temporary arrays -----
REAL :: xh
!---- local misc. variables
INTEGER :: i,j,k,ik
!-----xkw are the absorption coefficients for the first
! k-distribution function due to water vapor line absorption
! (tables 4 and 7). units are cm**2/g
DATA xkw / 29.55 , 4.167E-1, 1.328E-2, 5.250E-4, &
5.25E-4, 2.340E-3, 1.320E-0, 5.250E-4/
!-----mw are the ratios between neighboring absorption coefficients
! for water vapor line absorption (tables 4 and 7).
DATA mw /6,6,8,6,6,8,6,16/
!-----aw and bw (table 3) are the coefficients for temperature scaling
! in eq. (25).
DATA aw/ 0.0021, 0.0140, 0.0167, 0.0302, &
0.0307, 0.0154, 0.0008, 0.0096/
DATA bw/ -1.01E-5, 5.57E-5, 8.54E-5, 2.96E-4, &
2.86E-4, 7.53E-5,-3.52E-6, 1.64E-5/
!-----expmn is an external function
REAL :: expmn
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
! Beginning of executable code...
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
!**********************************************************************
! note that the 3 sub-bands in band 3 use the same set of xkw, aw,
! and bw. therefore, h2oexp for these sub-bands are identical.
!**********************************************************************
DO k=1,np
DO j=1,n
DO i=1,m
!-----xh is the scaled water vapor amount for line absorption
! computed from (27).
xh = dh2o(i,j,k)*(pa(i,j,k)*0.002) &
* ( 1.+(aw(ib)+bw(ib)* dt(i,j,k))*dt(i,j,k) )
!-----h2oexp is the water vapor transmittance of the layer (k2-1)
! due to line absorption
h2oexp(i,j,k,1) = expmn(-xh*xkw(ib))
END DO
END DO
END DO
DO ik=2,6
IF(mw(ib) == 6) THEN
DO k=1,np
DO j=1,n
DO i=1,m
xh = h2oexp(i,j,k,ik-1)*h2oexp(i,j,k,ik-1)
h2oexp(i,j,k,ik) = xh*xh*xh
END DO
END DO
END DO
ELSE IF(mw(ib) == 8) THEN
DO k=1,np
DO j=1,n
DO i=1,m
xh = h2oexp(i,j,k,ik-1)*h2oexp(i,j,k,ik-1)
xh = xh*xh
h2oexp(i,j,k,ik) = xh*xh
END DO
END DO
END DO
ELSE
DO k=1,np
DO j=1,n
DO i=1,m
xh = h2oexp(i,j,k,ik-1)*h2oexp(i,j,k,ik-1)
xh = xh*xh
xh = xh*xh
h2oexp(i,j,k,ik) = xh*xh
END DO
END DO
END DO
END IF
END DO
RETURN
END SUBROUTINE h2oexps
!
!
!##################################################################
!##################################################################
!###### ######
!###### SUBROUTINE CONEXPS ######
!###### ######
!###### Developed by ######
!###### ######
!###### Goddard Cumulus Ensemble Modeling Group, NASA ######
!###### ######
!###### Center for Analysis and Prediction of Storms ######
!###### University of Oklahoma ######
!###### ######
!##################################################################
!##################################################################
!
SUBROUTINE conexps(ib,m,n,np,dcont,conexp) 1
!
!-----------------------------------------------------------------------
!
! PURPOSE:
!
! Calculate exponentials for continuum absorption in individual
! layers.
!
!-----------------------------------------------------------------------
!
! AUTHOR: (a) Radiative Transfer Model: M.-D. Chou and M. Suarez
! (b) Cloud Optics:Tao, Lang, Simpson, Sui, Ferrier and
! Chou (1996)
!
! MODIFICATION HISTORY:
!
! 03/15/1996 (Yuhe Liu)
! Adopted the original code and formatted it in accordance with the
! ARPS coding standard.
!
!-----------------------------------------------------------------------
!
! ORIGINAL COMMENTS:
!
!**********************************************************************
! compute exponentials for continuum absorption in individual layers.
!
!---- input parameters
! spectral band (ib)
! number of grid intervals in zonal direction (m)
! number of grid intervals in meridional direction (n)
! number of layers (np)
! layer scaled water vapor amount for continuum absorption (dcont)
!
!---- output parameters
! 1 or 3 exponentials for each layer (conexp)
!
!**********************************************************************
!
!fpp$ expand (expmn)
!dir$ inline always expmn
!*$* inline routine (expmn)
!
!-----------------------------------------------------------------------
!
! Variable Declarations.
!
!-----------------------------------------------------------------------
!
IMPLICIT NONE
INTEGER :: ib,m,n,np,i,j,k,iq
!---- input parameters ------
REAL :: dcont(m,n,np)
!---- updated parameters -----
REAL :: conexp(m,n,np,3)
!---- static data -----
INTEGER :: NE(8)
REAL :: xke(8)
!-----xke are the absorption coefficients for the first
! k-distribution function due to water vapor continuum absorption
! (table 6). units are cm**2/g
DATA xke / 0.00, 0.00, 27.40, 15.8, &
9.40, 7.75, 0.0, 0.0/
!-----ne is the number of terms in computing water vapor
! continuum transmittance (Table 6).
! band 3 is divided into 3 sub-bands.
DATA NE /0,0,3,1,1,1,0,0/
!
!-----------------------------------------------------------------------
!
! Functions:
!
!-----------------------------------------------------------------------
!
!-----expmn is an external function
REAL :: expmn
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
! Beginning of executable code...
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
DO k=1,np
DO j=1,n
DO i=1,m
conexp(i,j,k,1) = expmn(-dcont(i,j,k)*xke(ib))
END DO
END DO
END DO
IF (ib == 3) THEN
!-----the absorption coefficients for sub-bands 3b (iq=2) and 3a (iq=3)
! are, respectively, double and quadruple that for sub-band 3c (iq=1)
! (table 6).
DO iq=2,3
DO k=1,np
DO j=1,n
DO i=1,m
conexp(i,j,k,iq) = conexp(i,j,k,iq-1) *conexp(i,j,k,iq-1)
END DO
END DO
END DO
END DO
END IF
RETURN
END SUBROUTINE conexps
!
!
!##################################################################
!##################################################################
!###### ######
!###### SUBROUTINE CO2EXPS ######
!###### ######
!###### Developed by ######
!###### ######
!###### Goddard Cumulus Ensemble Modeling Group, NASA ######
!###### ######
!###### Center for Analysis and Prediction of Storms ######
!###### University of Oklahoma ######
!###### ######
!##################################################################
!##################################################################
!
SUBROUTINE co2exps(m,n,np,dco2,pa,dt,co2exp) 1
!
!-----------------------------------------------------------------------
!
! PURPOSE:
!
! Calculate co2 exponentials for individual layers.
!
!-----------------------------------------------------------------------
!
! AUTHOR: (a) Radiative Transfer Model: M.-D. Chou and M. Suarez
! (b) Cloud Optics:Tao, Lang, Simpson, Sui, Ferrier and
! Chou (1996)
!
! MODIFICATION HISTORY:
!
! 03/15/1996 (Yuhe Liu)
! Adopted the original code and formatted it in accordance with the
! ARPS coding standard.
!
!-----------------------------------------------------------------------
!
! ORIGINAL COMMENTS:
!
!
!**********************************************************************
! compute co2 exponentials for individual layers.
!
!---- input parameters
! number of grid intervals in zonal direction (m)
! number of grid intervals in meridional direction (n)
! number of layers (np)
! layer co2 amount (dco2)
! layer pressure (pa)
! layer temperature minus 250K (dt)
!
!---- output parameters
! 6 exponentials for each layer (co2exp)
!**********************************************************************
!
!fpp$ expand (expmn)
!dir$ inline always expmn
!*$* inline routine (expmn)
!
!-----------------------------------------------------------------------
!
! Variable Declarations.
!
!-----------------------------------------------------------------------
!
IMPLICIT NONE
INTEGER :: m,n,np,i,j,k
!---- input parameters -----
REAL :: dco2(m,n,np)
REAL :: pa(m,n,np)
REAL :: dt(m,n,np)
!---- output parameters -----
REAL :: co2exp(m,n,np,6,2)
!---- static data -----
REAL :: xkc(2),ac(2),bc(2),pm(2),prc(2)
!---- temporary arrays -----
REAL :: xc
!-----xkc is the absorption coefficients for the
! first k-distribution function due to co2 (table 7).
! units are 1/(cm-atm)stp.
DATA xkc/2.656E-5,2.656E-3/
!-----parameters (table 3) for computing the scaled co2 amount
! using (27).
DATA prc/ 300.0, 30.0/
DATA pm / 0.5, 0.85/
DATA ac / 0.0182, 0.0042/
DATA bc /1.07E-4,2.00E-5/
!
!-----------------------------------------------------------------------
!
! Functions:
!
!-----------------------------------------------------------------------
!
!-----function expmn
REAL :: expmn
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
! Beginning of executable code...
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
DO k=1,np
DO j=1,n
DO i=1,m
!-----compute the scaled co2 amount from eq. (27) for band-wings
! (sub-bands 3a and 3c).
xc = dco2(i,j,k)*(pa(i,j,k)/prc(1))**pm(1) &
*(1.+(ac(1)+bc(1)*dt(i,j,k))*dt(i,j,k))
!-----six exponential by powers of 8 (table 7).
co2exp(i,j,k,1,1)=expmn(-xc*xkc(1))
xc=co2exp(i,j,k,1,1)*co2exp(i,j,k,1,1)
xc=xc*xc
co2exp(i,j,k,2,1)=xc*xc
xc=co2exp(i,j,k,2,1)*co2exp(i,j,k,2,1)
xc=xc*xc
co2exp(i,j,k,3,1)=xc*xc
xc=co2exp(i,j,k,3,1)*co2exp(i,j,k,3,1)
xc=xc*xc
co2exp(i,j,k,4,1)=xc*xc
xc=co2exp(i,j,k,4,1)*co2exp(i,j,k,4,1)
xc=xc*xc
co2exp(i,j,k,5,1)=xc*xc
xc=co2exp(i,j,k,5,1)*co2exp(i,j,k,5,1)
xc=xc*xc
co2exp(i,j,k,6,1)=xc*xc
!-----compute the scaled co2 amount from eq. (27) for band-center
! region (sub-band 3b).
xc = dco2(i,j,k)*(pa(i,j,k)/prc(2))**pm(2) &
*(1.+(ac(2)+bc(2)*dt(i,j,k))*dt(i,j,k))
co2exp(i,j,k,1,2)=expmn(-xc*xkc(2))
xc=co2exp(i,j,k,1,2)*co2exp(i,j,k,1,2)
xc=xc*xc
co2exp(i,j,k,2,2)=xc*xc
xc=co2exp(i,j,k,2,2)*co2exp(i,j,k,2,2)
xc=xc*xc
co2exp(i,j,k,3,2)=xc*xc
xc=co2exp(i,j,k,3,2)*co2exp(i,j,k,3,2)
xc=xc*xc
co2exp(i,j,k,4,2)=xc*xc
xc=co2exp(i,j,k,4,2)*co2exp(i,j,k,4,2)
xc=xc*xc
co2exp(i,j,k,5,2)=xc*xc
xc=co2exp(i,j,k,5,2)*co2exp(i,j,k,5,2)
xc=xc*xc
co2exp(i,j,k,6,2)=xc*xc
END DO
END DO
END DO
RETURN
END SUBROUTINE co2exps
!
!
!##################################################################
!##################################################################
!###### ######
!###### SUBROUTINE COLUMN ######
!###### ######
!###### Developed by ######
!###### ######
!###### Goddard Cumulus Ensemble Modeling Group, NASA ######
!###### ######
!###### Center for Analysis and Prediction of Storms ######
!###### University of Oklahoma ######
!###### ######
!##################################################################
!##################################################################
!
SUBROUTINE column(m,n,np,pa,dt,sabs0,sabs,spre,stem) 3
!
!-----------------------------------------------------------------------
!
! PURPOSE:
!
! Calculate column-integrated (from top of the model atmosphere)
! absorber amount, absorber-weighted pressure and temperature.
!
!-----------------------------------------------------------------------
!
! AUTHOR: (a) Radiative Transfer Model: M.-D. Chou and M. Suarez
! (b) Cloud Optics:Tao, Lang, Simpson, Sui, Ferrier and
! Chou (1996)
!
! MODIFICATION HISTORY:
!
! 03/15/1996 (Yuhe Liu)
! Adopted the original code and formatted it in accordance with the
! ARPS coding standard.
!
!-----------------------------------------------------------------------
!
! ORIGINAL COMMENTS:
!
!**************************************************************************
!-----compute column-integrated (from top of the model atmosphere)
! absorber amount (sabs), absorber-weighted pressure (spre) and
! temperature (stem).
! computations of spre and stem follows eqs. (37) and (38).
!
!--- input parameters
! number of soundings in zonal direction (m)
! number of soundings in meridional direction (n)
! number of atmospheric layers (np)
! layer pressure (pa)
! layer temperature minus 250K (dt)
! layer absorber amount (sabs0)
!
!--- output parameters
! column-integrated absorber amount (sabs)
! column absorber-weighted pressure (spre)
! column absorber-weighted temperature (stem)
!
!--- units of pa and dt are mb and k, respectively.
! units of sabs are g/cm**2 for water vapor and (cm-atm)stp for co2 and o3
!**************************************************************************
!
!-----------------------------------------------------------------------
!
! Variable Declarations.
!
!-----------------------------------------------------------------------
!
IMPLICIT NONE
INTEGER :: m,n,np,i,j,k
!---- input parameters -----
REAL :: pa(m,n,np)
REAL :: dt(m,n,np)
REAL :: sabs0(m,n,np)
!---- output parameters -----
REAL :: sabs(m,n,np+1)
REAL :: spre(m,n,np+1)
REAL :: stem(m,n,np+1)
!*********************************************************************
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
! Beginning of executable code...
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
DO j=1,n
DO i=1,m
sabs(i,j,1)=0.0
spre(i,j,1)=0.0
stem(i,j,1)=0.0
END DO
END DO
DO k=1,np
DO j=1,n
DO i=1,m
sabs(i,j,k+1)=sabs(i,j,k)+sabs0(i,j,k)
spre(i,j,k+1)=spre(i,j,k)+pa(i,j,k)*sabs0(i,j,k)
stem(i,j,k+1)=stem(i,j,k)+dt(i,j,k)*sabs0(i,j,k)
END DO
END DO
END DO
RETURN
END SUBROUTINE column
!
!
!##################################################################
!##################################################################
!###### ######
!###### SUBROUTINE TABLUP ######
!###### ######
!###### Developed by ######
!###### ######
!###### Goddard Cumulus Ensemble Modeling Group, NASA ######
!###### ######
!###### Center for Analysis and Prediction of Storms ######
!###### University of Oklahoma ######
!###### ######
!##################################################################
!##################################################################
!
SUBROUTINE tablup(k1,k2,m,n,np,nx,nh,nt,sabs,spre,stem,w1,p1, & 5
dwe,dpe,coef1,coef2,coef3,tran)
!
!-----------------------------------------------------------------------
!
! PURPOSE:
!
! Calculate water vapor, co2, and o3 transmittances using table
! look-up. rlwopt = 0, or high=.false.
!
!-----------------------------------------------------------------------
!
! AUTHOR: (a) Radiative Transfer Model: M.-D. Chou and M. Suarez
! (b) Cloud Optics:Tao, Lang, Simpson, Sui, Ferrier and
! Chou (1996)
!
! MODIFICATION HISTORY:
!
! 03/15/1996 (Yuhe Liu)
! Adopted the original code and formatted it in accordance with the
! ARPS coding standard.
!
!-----------------------------------------------------------------------
!
! ORIGINAL COMMENTS:
!
!**********************************************************************
! compute water vapor, co2, and o3 transmittances between levels k1 and k2
! using table look-up for m x n soundings.
!
! Calculations follow Eq. (40) of Chou and Suarez (1995)
!
!---- input ---------------------
! indices for pressure levels (k1 and k2)
! number of grid intervals in zonal direction (m)
! number of grid intervals in meridional direction (n)
! number of atmospheric layers (np)
! number of pressure intervals in the table (nx)
! number of absorber amount intervals in the table (nh)
! number of tables copied (nt)
! column-integrated absorber amount (sabs)
! column absorber amount-weighted pressure (spre)
! column absorber amount-weighted temperature (stem)
! first value of absorber amount (log10) in the table (w1)
! first value of pressure (log10) in the table (p1)
! size of the interval of absorber amount (log10) in the table (dwe)
! size of the interval of pressure (log10) in the table (dpe)
! pre-computed coefficients (coef1, coef2, and coef3)
!
!---- updated ---------------------
! transmittance (tran)
!
! Note:
! (1) units of sabs are g/cm**2 for water vapor and (cm-atm)stp for co2 and o3.
! (2) units of spre and stem are, respectively, mb and K.
! (3) there are nt identical copies of the tables (coef1, coef2, and
! coef3). the prupose of using the multiple copies of tables is
! to increase the speed in parallel (vectorized) computations.
! if such advantage does not exist, nt can be set to 1.
!
!**********************************************************************
!
!-----------------------------------------------------------------------
!
! Variable declarations
!
!-----------------------------------------------------------------------
!
IMPLICIT NONE
INTEGER :: k1,k2,m,n,np,nx,nh,nt,i,j
!---- input parameters -----
REAL :: w1,p1,dwe,dpe
REAL :: sabs(m,n,np+1)
REAL :: spre(m,n,np+1)
REAL :: stem(m,n,np+1)
REAL :: coef1(nx,nh,nt)
REAL :: coef2(nx,nh,nt)
REAL :: coef3(nx,nh,nt)
!---- update parameter -----
REAL :: tran(m,n)
!---- temporary variables -----
REAL :: x1,x2,x3,we,pe,fw,fp,pa,pb,pc,ax,ba,bb,t1,ca,cb,t2
INTEGER :: iw,ip,nn
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
! Beginning of executable code...
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
DO j=1,n
DO i=1,m
nn=MOD(i,nt)+1
x1=sabs(i,j,k2)-sabs(i,j,k1)
x2=(spre(i,j,k2)-spre(i,j,k1))/x1
x3=(stem(i,j,k2)-stem(i,j,k1))/x1
we=(LOG10(x1)-w1)/dwe
pe=(LOG10(x2)-p1)/dpe
we=MAX(we,w1-2.*dwe)
pe=MAX(pe,p1)
iw=INT(we+1.5)
ip=INT(pe+1.5)
iw=MIN(iw,nh-1)
iw=MAX(iw, 2)
ip=MIN(ip,nx-1)
ip=MAX(ip, 1)
fw=we-FLOAT(iw-1)
fp=pe-FLOAT(ip-1)
!-----linear interpolation in pressure
pa = coef1(ip,iw-1,nn)*(1.-fp)+coef1(ip+1,iw-1,nn)*fp
pb = coef1(ip,iw, nn)*(1.-fp)+coef1(ip+1,iw, nn)*fp
pc = coef1(ip,iw+1,nn)*(1.-fp)+coef1(ip+1,iw+1,nn)*fp
!-----quadratic interpolation in absorber amount for coef1
ax = (-pa*(1.-fw)+pc*(1.+fw)) *fw*0.5 + pb*(1.-fw*fw)
!-----linear interpolation in absorber amount for coef2 and coef3
ba = coef2(ip,iw, nn)*(1.-fp)+coef2(ip+1,iw, nn)*fp
bb = coef2(ip,iw+1,nn)*(1.-fp)+coef2(ip+1,iw+1,nn)*fp
t1 = ba*(1.-fw) + bb*fw
ca = coef3(ip,iw, nn)*(1.-fp)+coef3(ip+1,iw, nn)*fp
cb = coef3(ip,iw+1,nn)*(1.-fp)+coef3(ip+1,iw+1,nn)*fp
t2 = ca*(1.-fw) + cb*fw
!-----update the total transmittance between levels k1 and k2
tran(i,j)= (ax + (t1+t2*x3) * x3)*tran(i,j)
END DO
END DO
RETURN
END SUBROUTINE tablup
!
!
!##################################################################
!##################################################################
!###### ######
!###### SUBROUTINE WVKDIS ######
!###### ######
!###### Developed by ######
!###### ######
!###### Goddard Cumulus Ensemble Modeling Group, NASA ######
!###### ######
!###### Center for Analysis and Prediction of Storms ######
!###### University of Oklahoma ######
!###### ######
!##################################################################
!##################################################################
!
SUBROUTINE wvkdis(ib,m,n,np,k,h2oexp,conexp,th2o,tcon,tran) 1
!
!-----------------------------------------------------------------------
!
! PURPOSE:
!
! Calculate water vapor transmittance using the k-distribution
! method.
!
!-----------------------------------------------------------------------
!
! AUTHOR: (a) Radiative Transfer Model: M.-D. Chou and M. Suarez
! (b) Cloud Optics:Tao, Lang, Simpson, Sui, Ferrier and
! Chou (1996)
!
! MODIFICATION HISTORY:
!
! 03/15/1996 (Yuhe Liu)
! Adopted the original code and formatted it in accordance with the
! ARPS coding standard.
!
!-----------------------------------------------------------------------
!
! ORIGINAL COMMENTS:
!
!**********************************************************************
! compute water vapor transmittance between levels k1 and k2 for
! m x n soundings using the k-distribution method.
!
! computations follow eqs. (34), (46), (50) and (52).
!
!---- input parameters
! spectral band (ib)
! number of grid intervals in zonal direction (m)
! number of grid intervals in meridional direction (n)
! number of levels (np)
! current level (k)
! exponentials for line absorption (h2oexp)
! exponentials for continuum absorption (conexp)
!
!---- updated parameters
! transmittance between levels k1 and k2 due to
! water vapor line absorption (th2o)
! transmittance between levels k1 and k2 due to
! water vapor continuum absorption (tcon)
! total transmittance (tran)
!
!**********************************************************************
!
!-----------------------------------------------------------------------
!
! Variable declarations
!
!-----------------------------------------------------------------------
!
IMPLICIT NONE
INTEGER :: ib,m,n,np,k,i,j
!---- input parameters ------
REAL :: conexp(m,n,np,3)
REAL :: h2oexp(m,n,np,6)
!---- updated parameters -----
REAL :: th2o(m,n,6)
REAL :: tcon(m,n,3)
REAL :: tran(m,n)
!---- static data -----
INTEGER :: NE(8)
REAL :: fkw(6,8),gkw(6,3)
!---- temporary variable -----
REAL :: trnth2o
!-----fkw is the planck-weighted k-distribution function due to h2o
! line absorption given in table 4 of Chou and Suarez (1995).
! the k-distribution function for the third band, fkw(*,3), is not used
DATA fkw / 0.2747,0.2717,0.2752,0.1177,0.0352,0.0255, &
0.1521,0.3974,0.1778,0.1826,0.0374,0.0527, &
6*1.00, &
0.4654,0.2991,0.1343,0.0646,0.0226,0.0140, &
0.5543,0.2723,0.1131,0.0443,0.0160,0.0000, &
0.1846,0.2732,0.2353,0.1613,0.1146,0.0310, &
0.0740,0.1636,0.4174,0.1783,0.1101,0.0566, &
0.1437,0.2197,0.3185,0.2351,0.0647,0.0183/
!-----gkw is the planck-weighted k-distribution function due to h2o
! line absorption in the 3 subbands (800-720,620-720,540-620 /cm)
! of band 3 given in table 7. Note that the order of the sub-bands
! is reversed.
DATA gkw/ 0.1782,0.0593,0.0215,0.0068,0.0022,0.0000, &
0.0923,0.1675,0.0923,0.0187,0.0178,0.0000, &
0.0000,0.1083,0.1581,0.0455,0.0274,0.0041/
!-----ne is the number of terms used in each band to compute water vapor
! continuum transmittance (table 6).
DATA NE /0,0,3,1,1,1,0,0/
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
! Beginning of executable code...
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
!-----tco2 are the six exp factors between levels k1 and k2
! tran is the updated total transmittance between levels k1 and k2
!-----th2o is the 6 exp factors between levels k1 and k2 due to
! h2o line absorption.
!-----tcon is the 3 exp factors between levels k1 and k2 due to
! h2o continuum absorption.
!-----trnth2o is the total transmittance between levels k1 and k2 due
! to both line and continuum absorption computed from eq. (52).
DO j=1,n
DO i=1,m
th2o(i,j,1) = th2o(i,j,1)*h2oexp(i,j,k,1)
th2o(i,j,2) = th2o(i,j,2)*h2oexp(i,j,k,2)
th2o(i,j,3) = th2o(i,j,3)*h2oexp(i,j,k,3)
th2o(i,j,4) = th2o(i,j,4)*h2oexp(i,j,k,4)
th2o(i,j,5) = th2o(i,j,5)*h2oexp(i,j,k,5)
th2o(i,j,6) = th2o(i,j,6)*h2oexp(i,j,k,6)
END DO
END DO
IF (NE(ib) == 0) THEN
DO j=1,n
DO i=1,m
trnth2o =(fkw(1,ib)*th2o(i,j,1) &
+ fkw(2,ib)*th2o(i,j,2) &
+ fkw(3,ib)*th2o(i,j,3) &
+ fkw(4,ib)*th2o(i,j,4) &
+ fkw(5,ib)*th2o(i,j,5) &
+ fkw(6,ib)*th2o(i,j,6))
tran(i,j)=tran(i,j)*trnth2o
END DO
END DO
ELSE IF (NE(ib) == 1) THEN
DO j=1,n
DO i=1,m
tcon(i,j,1)= tcon(i,j,1)*conexp(i,j,k,1)
trnth2o =(fkw(1,ib)*th2o(i,j,1) &
+ fkw(2,ib)*th2o(i,j,2) &
+ fkw(3,ib)*th2o(i,j,3) &
+ fkw(4,ib)*th2o(i,j,4) &
+ fkw(5,ib)*th2o(i,j,5) &
+ fkw(6,ib)*th2o(i,j,6))*tcon(i,j,1)
tran(i,j)=tran(i,j)*trnth2o
END DO
END DO
ELSE
DO j=1,n
DO i=1,m
tcon(i,j,1)= tcon(i,j,1)*conexp(i,j,k,1)
tcon(i,j,2)= tcon(i,j,2)*conexp(i,j,k,2)
tcon(i,j,3)= tcon(i,j,3)*conexp(i,j,k,3)
trnth2o = ( gkw(1,1)*th2o(i,j,1) &
+ gkw(2,1)*th2o(i,j,2) &
+ gkw(3,1)*th2o(i,j,3) &
+ gkw(4,1)*th2o(i,j,4) &
+ gkw(5,1)*th2o(i,j,5) &
+ gkw(6,1)*th2o(i,j,6) ) * tcon(i,j,1) &
+ ( gkw(1,2)*th2o(i,j,1) &
+ gkw(2,2)*th2o(i,j,2) &
+ gkw(3,2)*th2o(i,j,3) &
+ gkw(4,2)*th2o(i,j,4) &
+ gkw(5,2)*th2o(i,j,5) &
+ gkw(6,2)*th2o(i,j,6) ) * tcon(i,j,2) &
+ ( gkw(1,3)*th2o(i,j,1) &
+ gkw(2,3)*th2o(i,j,2) &
+ gkw(3,3)*th2o(i,j,3) &
+ gkw(4,3)*th2o(i,j,4) &
+ gkw(5,3)*th2o(i,j,5) &
+ gkw(6,3)*th2o(i,j,6) ) * tcon(i,j,3)
tran(i,j)=tran(i,j)*trnth2o
END DO
END DO
END IF
RETURN
END SUBROUTINE wvkdis
!
!
!##################################################################
!##################################################################
!###### ######
!###### SUBROUTINE CO2KDIS ######
!###### ######
!###### Developed by ######
!###### ######
!###### Goddard Cumulus Ensemble Modeling Group, NASA ######
!###### ######
!###### Center for Analysis and Prediction of Storms ######
!###### University of Oklahoma ######
!###### ######
!##################################################################
!##################################################################
!
SUBROUTINE co2kdis(m,n,np,k,co2exp,tco2,tran) 1
!
!-----------------------------------------------------------------------
!
! PURPOSE:
!
! Calculate co2 transmittances using the k-distribution method
!
!
!-----------------------------------------------------------------------
!
! AUTHOR: (a) Radiative Transfer Model: M.-D. Chou and M. Suarez
! (b) Cloud Optics:Tao, Lang, Simpson, Sui, Ferrier and
! Chou (1996)
!
! MODIFICATION HISTORY:
!
! 03/15/1996 (Yuhe Liu)
! Adopted the original code and formatted it in accordance with the
! ARPS coding standard.
!
!-----------------------------------------------------------------------
!
! ORIGINAL COMMENTS:
!
!**********************************************************************
! compute co2 transmittances between levels k1 and k2 for m x n soundings
! using the k-distribution method with linear pressure scaling.
!
! computations follow eq. (34).
!
!---- input parameters
! number of grid intervals in zonal direction (m)
! number of grid intervals in meridional direction (n)
!
!---- updated parameters
! transmittance between levels k1 and k2 due to co2 absorption
! for the various values of the absorption coefficient (tco2)
! total transmittance (tran)
!
!**********************************************************************
!
!-----------------------------------------------------------------------
!
! Variable declarations
!
!-----------------------------------------------------------------------
!
IMPLICIT NONE
INTEGER :: m,n,np,k,i,j
!---- input parameters -----
REAL :: co2exp(m,n,np,6,2)
!---- updated parameters -----
REAL :: tco2(m,n,6,2)
REAL :: tran(m,n)
!---- static data -----
REAL :: gkc(6,2)
!---- temporary variable -----
REAL :: xc
!-----gkc is the planck-weighted co2 k-distribution function
! in the band-wing and band-center regions given in table 7.
! for computing efficiency, sub-bands 3a and 3c are combined.
DATA gkc/ 0.1395,0.1407,0.1549,0.1357,0.0182,0.0220, &
0.0766,0.1372,0.1189,0.0335,0.0169,0.0059/
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
! Beginning of executable code...
!
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!
!-----tco2 is the 6 exp factors between levels k1 and k2.
! xc is the total co2 transmittance given by eq. (53).
DO j=1,n
DO i=1,m
!-----band-wings
tco2(i,j,1,1)=tco2(i,j,1,1)*co2exp(i,j,k,1,1)
xc= gkc(1,1)*tco2(i,j,1,1)
tco2(i,j,2,1)=tco2(i,j,2,1)*co2exp(i,j,k,2,1)
xc=xc+gkc(2,1)*tco2(i,j,2,1)
tco2(i,j,3,1)=tco2(i,j,3,1)*co2exp(i,j,k,3,1)
xc=xc+gkc(3,1)*tco2(i,j,3,1)
tco2(i,j,4,1)=tco2(i,j,4,1)*co2exp(i,j,k,4,1)
xc=xc+gkc(4,1)*tco2(i,j,4,1)
tco2(i,j,5,1)=tco2(i,j,5,1)*co2exp(i,j,k,5,1)
xc=xc+gkc(5,1)*tco2(i,j,5,1)
tco2(i,j,6,1)=tco2(i,j,6,1)*co2exp(i,j,k,6,1)
xc=xc+gkc(6,1)*tco2(i,j,6,1)
!-----band-center region
tco2(i,j,1,2)=tco2(i,j,1,2)*co2exp(i,j,k,1,2)
xc=xc+gkc(1,2)*tco2(i,j,1,2)
tco2(i,j,2,2)=tco2(i,j,2,2)*co2exp(i,j,k,2,2)
xc=xc+gkc(2,2)*tco2(i,j,2,2)
tco2(i,j,3,2)=tco2(i,j,3,2)*co2exp(i,j,k,3,2)
xc=xc+gkc(3,2)*tco2(i,j,3,2)
tco2(i,j,4,2)=tco2(i,j,4,2)*co2exp(i,j,k,4,2)
xc=xc+gkc(4,2)*tco2(i,j,4,2)
tco2(i,j,5,2)=tco2(i,j,5,2)*co2exp(i,j,k,5,2)
xc=xc+gkc(5,2)*tco2(i,j,5,2)
tco2(i,j,6,2)=tco2(i,j,6,2)*co2exp(i,j,k,6,2)
xc=xc+gkc(6,2)*tco2(i,j,6,2)
tran(i,j)=tran(i,j)*xc
END DO
END DO
RETURN
END SUBROUTINE co2kdis