Compositional Variation of the Dayside Martian Ionosphere: Inference from Photochemical Equilibrium Computations

Abstract The Martian ionosphere plays a crucial role in driving the interactions of planet with solar photons and wind particles. variations dayside several controlling factors, including extreme ultraviolet radiation, background atmosphere, underlying thermal structure, have been topic extensive research terms electron distribution. In contrast, how ionospheric composition varies has not systematically investigated, that is attempted this study based on photochemical equilibrium computations performed at 100–200 km altitude, large number reactions. Our calculations reveal following compositional as natural outcomes chemistry Mars. (1) With increasing irradiance, proportions majority nonterminal ions are enhanced expense reduced terminal ions, O 2 + , HCO + NO H 3 O . (2) At high temperatures, proportion modestly reduced, whereas other species nearly unaffected. (3) response to upper atmospheric complicated, showing strong negative many trace ambient CO 2 O, CO, well positive protonated nitrogen-bearing N water-group ${\mathrm{HO}}_{2}^{+}$?> HO As an application model results, recent ion measurements made board Mars Atmosphere Volatile Evolution used provide hints about realistic atmosphere.