A coupled model of the D and E regions of Mars' ionosphere for flare and non-flare electron density profiles

Abstract

Solar X-ray flare responses in the E region of Mars' ionosphere were observed from Mars Global Surveyor (MGS) on 6 April 2001 and 17 March 2003. We have developed a coupled model for the calculation of Ionospheric Electron Content (IEC), flare and non-flare electron density profiles due to impact of X-rays (0.5–90 Å) and Galactic Cosmic Rays (GCR) in the D and E regions of Mars' ionosphere simultaneously. In the non-flare profile the D layer is produced at 25 km due to impact of GCR and hard X-rays (0.5–3 Å) with electron densities 1.0 × 102 cm−3 and 8 × 102 cm−3 respectively while E layer is produced at 100–110 km with electron density ~ 4–5 × 104 cm−3 due to impact of soft X-rays (3–90 Å). The D flare peak is produced at 30 km with electron density ~ 2–4 × 104 cm−3. The E flare peak is produced at 100 km with electron density 1–2 × 105 cm−3. The predicted flare E-peak density is higher by a factor of ~2 than the measurements carried out by MGS. The D peak density of flare profile is larger by 1–2 orders of magnitude than that produced for non-flare profiles. Our model suggests that hard X-ray is a major source of the D layer in the Martian ionosphere.