#include "dims.h"
      SUBROUTINE CMPCO
      use cons_module,only: len1,len2,kmax
      implicit none
C     ****
C     ****     ADVANCES PSI(CO) BY ONE TIME STEP
C     ****
#include "params.h"
#include "fcom.h"
#include "vscr.h"
#include "index.h"
#include "buff.h"
#include "crates_const.h"
#include "crates_tdep.h"
#include "lowbnd.h"
#include "phys.h"
#include "compcom.h"
#include "mwt.h"
#include "diffk.h"
#include "cmpdat.h"
!
! Local:
      real :: PHICO(3)=(/0.833,1.427,0.852/)
      integer :: nmsk,nopk,npcok,npco2k,npo1k,npch4k,njco2tk,nphoxk,i,k,
     |  ibnd,ibndb
      real :: alfa,xyco
C     ****
C     ****     NUMBER DENSITY MIXING RATIO OF CO AT LOWER BOUNDARY
C     ****
      NMSK = NJ+NMS
      NOPK = NJ+NOP
      NPCOK = NJ+NPCO
      NPCO2K = NJ+NPCO2
      NPO1K = NJ+NPO1
      NPCH4K = NJ+NPCH4
      NJCO2TK = NJCO2T-1
      NPHOXK = NJ+NPHOX
      DO 1 I=1,LEN1
C     ****
C     ****     VALUE AT BOTTOM GIVEN BY SPECIFIED NUMBER DENSITY
C     ****     MIXING RATIO XCOLB
C     ****
      T1(I) = 0.
      T2(I) = 1.
      T3(I) = -XCOLB(J)*RMCO/F(I,NMSK)
C     ****
C     ****     ZERO DIFFUSIVE FLUX AT TOP
C     ****
      T4(I) = 0.
    1 CONTINUE
      DO 2 K=1,KMAX
      NJCO2TK = NJCO2TK+1
      DO 2 I=1,LEN1
      S4(I,K) = 0.5*(F(I,NJCO2TK)+F(I,NJCO2TK+1))
    2 CONTINUE
C     ****
C     ****     SOURCES
C     ****
      DO 3 I=1,LEN2
C     ****
C     ****     S3 = N*MBAR  (K+1/2)
C     ****
      S3(I,1) = XNMBAR(I,1)
C     ****
C     ****     S2 = NUMBER DENSITY PRODUCTION OF CO
C     ****
CC    S2(I,1) = S3(I,1)*(S4(I,1)+RK13*F(I,NOPK)+GAM15*
CC   1          XNO1D(I,1)/RMO1*S3(I,1))*F(I,NPCO2K)/RMCO2
CC   2          +(GAM1(I,1)*F(I,NPHOXK)/RMTRU(I,1)*RATIO1(I,1)*
CC   3          RATIO3(I,1)+(RKM5A+RKM5B)*XNO1D(I,1)/
CC   4          RMO1+GAM13(I,1)*F(I,NPO1K)/RMO1+DEL3(I,1)*RMCL(I,1)
CC   5          /(.5*(F(I,NMSK)+F(I,NMSK+1))))*F(I,NPCH4K)
CC   6          /RMCH4*S3(I,1)*S3(I,1)
      S2(I,1) = S3(I,1)*(S4(I,1)+RK13*F(I,NOPK)+GAM15*
     1          XNO1D(I,1)/RMO1*S3(I,1))*F(I,NPCO2K)/RMCO2
     2          +(RKM43(I,1)*F(I,NPHOXK)/RMTRU(I,1)*RATIO1(I,1)*
     3          RATIO3(I,1)+RKM45*XNO1D(I,1)/
     4          RMO1+RKM44(I,1)*F(I,NPO1K)/RMO1+DEL3(I,1)*RMCL(I,1)
     5          /(.5*(F(I,NMSK)+F(I,NMSK+1))))*F(I,NPCH4K)
     6          /RMCH4*S3(I,1)*S3(I,1)
C     ****
C     ****     S1 = NUMBER DENSITY LOSS OF CO
C     ****
      S1(I,1) = -S3(I,1)*(RKM42(I,1)*F(I,NPHOXK)/RMTRU(I,1)*
     1          RATIO1(I,1)*RATIO3(I,1)+GAM14(I,1)*
     2          F(I,NPO1K)/RMO1*S3(I,1)/(.5*(F(I,NMSK)+F(I,NMSK+1))))
    3 CONTINUE
      IBND=0
      IBNDB=0
      ALFA=0.
      XYCO=1.E-3
      CALL MINOR(NPCO,NPCONM,RMCO,PHICO,ALFA,IBND,IBNDB,WCO,XYCO,NPDHCO,
     1 difkk)
      RETURN
      END