Title: Effects of a Solar Flare on the Martian Hot O Corona and Photochemical Escape

Abstract

Here, we examine for the first time the flare–induced effects on the Martian hot O corona. The rapid ionospheric response to the increase in the soft X–ray flux (~800%) facilitates more hot O production at altitudes below the main ionospheric peak, but almost all of these atoms are thermalized before escape. In response to the increase in the extreme ultraviolet (EUV) flux (~170%), the overall upper ionospheric and thermospheric densities are enhanced, and the peak thermospheric responses are found ~1.5 hr later. The photochemical escape rate is predicted to increase by ~20% with the increases in the soft X–ray and EUV fluxes but decrease rapidly by ~13% about 2.5 hr later before recovering the preflare level. Since escaping hot O atoms are mostly produced at high altitudes where ionization by the EUV flux is the greatest, the main contributor to the 20% increase in escape rate is the enhancement in the EUV flux.

Authors:

Lee, Yuni  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-0463-7650"

Dong, Chuanfei  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-8990-094X"

Pawlowski, Dave ^[3]; Thiemann, Edward  ^[4];

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• Search DOE PAGES for ORCID "0000-0002-5305-9466"

Tenishev, Valeriy ^[5]; Mahaffy, Paul  ^[6];

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• Search DOE PAGES for ORCID "0000-0003-1896-1726"

Benna, Mehdi  ^[7];

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• Search DOE PAGES for ORCID "0000-0002-2770-4820"

Combi, Michael  ^[5];

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• Search DOE PAGES for ORCID "0000-0002-9805-0078"

Bougher, Stephen  ^[5];

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• Search DOE PAGES for ORCID "0000-0002-4178-2729"

Eparvier, Frank  ^[4]

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• Search DOE PAGES for ORCID "0000-0001-7143-2730"

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+ Show Author Affiliations

1. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); GESTAR, Univ. Space Research Assoc., Columbia, MD (United States)
2. Princeton Univ., Princeton, NJ (United States)
3. Eastern Michigan Univ., Ypsilanti, MI (United States)
4. Univ. of Colorado Boulder, Boulder, CO (United States)
5. Univ. of Michigan, Ann Arbor, MI (United States)
6. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
7. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland, Baltimore, MD (United States)

Publication Date:

Tue Jun 12 00:00:00 EDT 2018

Research Org.:

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:

This work was supported by NASA’s NGIMS/MAVEN investigation. Resources for all simulations were provided by NASA Center for Climate Simulation (NCCS).; USDOE

OSTI Identifier:

1472014

Resource Type:

Accepted Manuscript

Journal Name:

Geophysical Research Letters

Additional Journal Information:

Journal Volume: 45; Journal Issue: 14; Journal ID: ISSN 0094-8276

Publisher:

American Geophysical Union

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; Mars upper atmosphere; MAVEN mission; photochemical escape; hot O corona; solar flare; numerical simulation