The model used to produce the following images includes only the upflowing ions from the cleft ion fountain, the auroral zone and the polar cap as well as backsplash ENA produced by precipitating ring current O+ ions. Additional sources of ENA that will contribute to these images (which be added to future versions of the model) include the low energy component of the precipitating ring current ions H+ and O+ ions as well as precipitating cusp ions.

The assumptions and characteristics of the model are:

• The model assumes that the flux of ions coming from the ionosphere is proportional to the energy flux carried by precipitating electrons as given by the Hardy et al. [1987] empirical model.
• The total flux of O+ and H+ ions coming from the ionosphere is consistent with the results of Yau et al. [1988] and Pollock et al. [1990].
  

• A solution is found by launching many ions from the source altitude and tracking them as they follow field lines, drifting due to the convection electric field and losing energy to gravity.
• The ions begin life having velocities drawn from a perpendicularly heated biMaxwellian distribution whose perpendicular temperature is 10 times its parallel temperature.
• The magnetic field is assumed to be dipolar and the convection electric field model is that of Volland [1978].
• The neutral atmosphere used is that of the MSIS 86 model. O+ densities are from the IRI 90 model.
• The following charge exchange reactions are used.
  

• The solution found is steady state and depends mainly on Kp. There is also a dependence of F10.7 as given by the Yau et al. [1988] results.

Modeling Results

• Upflowing ion ENA movies during an IMAGE perigee pass
• Selected hydrogen images from the movie (all energy channels)
• Selected oxygen images from the movie (all energy channels)