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Mars's Dayside Upper Ionospheric Composition Is Affected by Magnetic Field Conditions.

ABSTRACT: Previous observations have shown that electron density and temperature in the dayside ionosphere of Mars vary between strongly and weakly magnetized regions of the planet. Here we use data from the Neutral Gas and Ion Mass Spectrometer (NGIMS) on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft to examine whether dayside ion densities and ionospheric composition also vary. We find that O⁺, O2+ , and CO2+ densities above ~200 km are greater in strongly magnetized regions than in weakly magnetized regions. Fractional abundances of ion species are also affected. The O+/O2+ ratio at 300-km altitude increases from ~0.5 in strongly magnetized regions to ~0.8 in weakly magnetized regions. Consequently, the plasma reservoir available for escape is fundamentally different between strongly magnetized and weakly magnetized regions.

SUBMITTER: Withers P

PROVIDER: S-EPMC7458070 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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Mars's Dayside Upper Ionospheric Composition Is Affected by Magnetic Field Conditions.

Withers Paul P Flynn C L CL Vogt M F MF Mayyasi M M Mahaffy P P Benna M M Elrod M M McFadden J P JP Dunn P P Liu G G Andersson L L England S S

Journal of geophysical research. Space physics 20190412 4

Previous observations have shown that electron density and temperature in the dayside ionosphere of Mars vary between strongly and weakly magnetized regions of the planet. Here we use data from the Neutral Gas and Ion Mass Spectrometer (NGIMS) on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft to examine whether dayside ion densities and ionospheric composition also vary. We find that O<sup>+</sup>, O 2 + , and CO 2 + densities above ~200 km are greater in strongly magnetize ...[more]

PMID: 32874820

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