The nitric oxide molecule is both a potential biomarker and an indicator of electron precipitation into the planet’s atmosphere. Using this fact, as well as a previously developed model for calculating NO concentrations in the N2–O2-dominated atmosphere, we can independently estimate the attenuation of e– precipitation under the influence of the planet’s magnetic field, Bpl. To make such an estimate, we need at least two points at different field values. We have one such point—the case of the Earth. Indeed, under fixed heliophysical conditions, we have experimental values of the NO concentration, as well as calculation results for the case of Earth’s magnetic field. The numerical model tested on the Earth can be used for other field values. However, calculations for arbitrary field values are only possible with additional, correct modeling of the entire complex of physical and chemical processes leading to the precipitation of magnetospheric electrons. This extremely complex problem can be solved relatively simply only in the case of a zero field value (Bpl = 0). The magnetohydrodynamic model of the interaction of the stellar wind with the atmosphere of a planet with Bpl = 0 that was previously developed and tested on Venus allows for the reliable determination of the parameters of precipitating electrons. Calculations of the NO concentration at Bpl = 0 provide a second point for estimation. Based on calculations for a quiet Sun, it was determined that the total number of NO molecules on a planet with Bpl = 0 could be 10 times greater than that on Earth. Thus, it can be argued that the presence of a planetary magnetic field with terrestrial parameters (a dipole field with an average value on the surface of ~50 μT) leads to a noticeable (by an order of magnitude under quiet Sun conditions) decrease in the energy flux of precipitating electrons. This allows for an independent estimate of the magnetic field’s role as a protective mechanism against the impacts of the solar wind.
Bisikalo et al. (Thu,) studied this question.