c------------------------------------------------------------------
c
      subroutine mkeo200(tn,xo2,xo,xn2,id,fout)
c
c 3/9/94:
c Given tn, xo2,xo,xn2 (species in cm-3), dimensioned id, return 
c   O2 (0-0) band emission:
c   (from Ian McDade, (mcdade@windic.yorku.ca) Mar 7, 1994 mail 
c    communication to Roble)
c
c The nighttime O2 Atmospheric (0-0) band emission rates in the region may be
c similarly modelled using:
c
c              A1 k1 [O]^2 {[N2]+[O2]} [O2]
c Vat=--------------------------------------------------(photons cm-3 sec-1)
c     {A2 + k2a[O2] + k2b[N2] + k2c[O]} {D'[O2] + D"[O]} 
c
c where [O], [O2] and [N2] are number densities cm-3
c A1 = 0.079 sec-1
c A2 = 0.083 sec-1
c k1 = 4.7E-33 (300/T)^2  cm6 sec-1
c k2a = 4.0E-17 cm3 sec-1
c k2b = 2.2E-15 cm3 sec-1
c k2c = 8.0E-14 cm3 sec-1
c D' = 6.6 dimensionless
c D" = 19  dimensionless
c
      dimension tn(id),xo2(id),xo(id),xn2(id),fout(id)
      parameter(a1=.079, a2=.083, rk2a=4.e-17, rk2b=2.2e-15, 
     +          rk2c=8.e-14, dp=6.6, dpp=19.)
c
      do k=1,id
        rk1 = 4.7e-33*(300./tn(k))**2
        fout(k) = (a1*rk1*xo(k)**2 * (xn2(k)+xo2(k)) * xo2(k)) /
     +    ((a2 + rk2a*xo2(k) + rk2b*xn2(k) + rk2c*xo(k)) *
     +    (dp*xo2(k)+dpp*xo(k)))
      enddo
      return
      end 
c
c------------------------------------------------------------------

