subroutine atmwrite(nnit,terr,ntit,herr,ndat,z,tmp,prs,den,col)
        implicit double precision (a-h,o-z)
        include "parameters.dat"
        dimension z(nd1),prs(nd1),tmp(nd1),den(nd1,0:4),col(nd1,0:4)

        open(unit=60,file='atm.int')

           write(unit=60,fmt=902) ndat,nnit,terr,ntit,herr
           write(unit=60,fmt=*) ' altitudes ' 
           write(unit=60,fmt=901) (z(n),n=1,ndat)
           write(unit=60,fmt=*) ' pressure ' 
           write(unit=60,fmt=901) (prs(n),n=1,ndat)
           write(unit=60,fmt=*) ' temperature ' 
           write(unit=60,fmt=901) (tmp(n),n=1,ndat)
           write(unit=60,fmt=*) ' atmospheric number density ' 
           write(unit=60,fmt=901) (den(n,0),n=1,ndat)
           write(unit=60,fmt=*) ' atmospheric column density ' 
           write(unit=60,fmt=901) (col(n,0),n=1,ndat)
           write(unit=60,fmt=*) ' methane number density ' 
           write(unit=60,fmt=901) (den(n,1),n=1,ndat)
           write(unit=60,fmt=*) ' methane column density ' 
           write(unit=60,fmt=901) (col(n,1),n=1,ndat)
           write(unit=60,fmt=*) ' acetlyene column density ' 
           write(unit=60,fmt=901) (den(n,2),n=1,ndat)
           write(unit=60,fmt=*) ' acetlyene column density ' 
           write(unit=60,fmt=901) (col(n,2),n=1,ndat)
           write(unit=60,fmt=*) ' ethane number density '
           write(unit=60,fmt=901) (den(n,3),n=1,ndat)
           write(unit=60,fmt=*) ' ethane column density ' 
           write(unit=60,fmt=901) (col(n,3),n=1,ndat)
           write(unit=60,fmt=*) ' HCN number density ' 
           write(unit=60,fmt=901) (den(n,4),n=1,ndat)
           write(unit=60,fmt=*) ' HCN column density ' 
           write(unit=60,fmt=901) (col(n,4),n=1,ndat)
        close(unit=60)

        return
 
 901    format(1x,1p10e11.3)
 902    format(1x,i4,3x,i3,e11.3,i3,e11.3)

        end