Flare X-ray photochemistry of the E region ionosphere of Mars

Abstract

Based on electron density profiles obtained from the Mars Global Surveyor (MGS) we report X-ray flare responses in the E region ionosphere of Mars during six events that occurred on 28 March and 6 April 2001, 17 and 18 March and 21 April 2003, and 19 February 2005. We have developed a time-dependent Analytical Yield Spectrum model to calculate a time series of photoionization rate, photoelectron impact ionization rate, photoelectron flux, ion density, electron density, and ionospheric electron content (IEC) of the E region for each flare day. The estimated production rate, flux, and densities increase by 1–2 orders of magnitude due to effect of these flares in the E region ionosphere of Mars. The estimated IEC are compared with the measured IEC. It is found that the normalized IEC of the simulated E layer increased by a factor of 5–10 at the flare time compared to a factor of 2 enhancements in the normalized IEC of the corresponding MGS profiles.