He²⁺ transport in the Martian upper atmosphere with an induced magnetic field

Abstract

[1] Solar wind helium may be a significant source of neutral helium in the Martian atmosphere. The precipitating particles also transfer mass, energy, and momentum. , and the energy flux is equal to 9-10 Â 10 -3 erg cm -2 s -1. The calculations of the upward flux have been made for the Martian atmosphere during solar minimum. It was found, that if the induced magnetic field is not introduced in the simulations the precipitating He 2+ ions are not backscattered at all by the Martian upper atmosphere. If we include a 20 nT horizontal magnetic field, a typical field measured by Mars Global Surveyor in the altitude range of 85-500 km, we find that up to 30%-40% of the energy flux of the precipitating He 2+ ions is backscattered depending on the velocity distribution of the precipitating particles. We thus conclude that the induced magnetic field plays a crucial role in the transport of charged particles in the upper atmosphere of Mars and, therefore, that it determines the energy deposition of the solar wind.

Monte Carlo study of interaction between solar wind plasma and Venusian upper atmosphere

“…precipitation (Shematovich et al, 2013) into the plan etary atmosphere were modified to take all Venus spe cific parameters into account, including the composi tion and temperature conditions of its neutral atmo sphere. The magnetic field around Venus induced by the solar wind plasma interaction with the partly ion ized atmosphere is based on the estimates by Zhang et al (2006;2010).…”

“…The Monte Carlo model for calculation of the pro ton and alpha particle precipitation into neutral atmo spheres (Schematovich et al, 2011;2013) was adapted for Venusian conditions and was used for calculations of reflected and upward directed particle fluxes. Pro ton and alpha particle spectra measured with the VEX ASPERA 4 instrument were used as input.…”

“…We use a Monte Carlo method to solve a kinetic equation which describes the transfport and kinetics of high energy (Е ≤ 10 keV) protons (Shematovich et al, 2011) and alpha particles (Shematovich et al, 2013) in the upper atmospheres of the terrestrial planets, taking into account the induced magnetic field. The follow ing points are considered:…”

Scientific problems addressed by the Spektr-UV space project (world space Observatory—Ultraviolet)

“…We should note the complex of mathematical models for the calibration and interpretation of UV images of polar aurorae, developed earlier and refined using Monte Carlo models [247][248][249][250][251][252]. These enable joint analyses of processes related to the precipitation of electrons, protons, and H atoms with high kinetic energies into the polar regions of a planetary atmosphere.…”

Proton and alpha particle precipitation onto the upper atmosphere of Venus

“…For Mars both observations and models (Chanteur et al, 2009;Modolo et al, 2005) indicate this might be the case. Models also suggest the magnetic field strength in the magnetic barrier regulates the net inflow and energy deposition of both protons and He 2 þ both on Mars and on Venus (Shematovich et al, 2011(Shematovich et al, , 2013(Shematovich et al, , 2014.…”