Calculated Photoelectron Flux Validation under Solar Minimum Condition using High-resolution Cross sections

Terrestrial low latitude Photoelectron flux spectrum observed by Atmospheric Explorer - E (AE-E) during a solar minimum condition has been compared with calculated photoelectron flux spectrum by Atmospheric Ultraviolet Radiance Integrated Code (AURIC, Strickland et al, 1999) using high-resolution photoabsorption and photoionization cross sections for N2 and O. Comparison between theory and measurement shows convincing agreement in low energy regime (0 - 100 eV) at all altitudes in between 150 km to 300 km where photoelectron transport effects are negligible. Our comparison accounts well resolved peaks between 20 eV to 30 eV due to photoionization of N2 and O at 25.2 eV and 27.2 eV, respectively, by the solar 304Å He II line. We also checked the large dip around 2.5 eV caused by the vibrational-rotational excitation of N2. Our study suggests that the numerical calculation done in AURIC is not unreasonable based on the comparison between data and model except 0 - 5 eV energy range. For the high altitude and high latitude data-model comparison, it is expected to account for pitch angle distribution of photoelectron flux. In future, we will employ the data observed by Fast Auroral Snapshot Explorer (FAST) for high-energy regime comparison between data and model.