Significant Space Weather Impact on the Escape of Hydrogen from Mars

Majd Mayyasi (1) , Dolon Bhattacharyya (1) , John Clarke (1) , Amy Catalano (1) , Mehdi Benna (2) , Paul Mahaffy (2) , Edward Thiemann (3) , Christina O. Lee (4) , Justin Deighan (3) , Sonal Jain (3) , Michael Chaffin (3) , Matteo Crismani (3) , William Mcclintock (3) , Ian Stewart (3) , Greg Holsclaw (3) , Arnaud Stiepen (5) , Franck Montmessin (6) , Nick Schneider (3) , Bruce Jakosky (3)

1 CSP - Center for Space Physics [Boston]
2 GSFC - NASA Goddard Space Flight Center
3 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
4 SSL - Space Sciences Laboratory [Berkeley]
5 LPAP - Laboratoire de Physique Atmosphérique et Planétaire
6 PLANETO - LATMOS

In September 2017, an active region of the Sun produced a series of strong flares and a coronal mass ejection that swept past Mars producing enhanced ionization and heating in the upper atmosphere. Emissions from atmospheric hydrogen Lyman‐α were also enhanced at Mars. Temperatures derived from neutral species scale heights were used in conjunction with the H Lyman‐α observations to simulate the effects of this space weather event on martian hydrogen properties in the exosphere. It was found that hydrogen abundance in the upper atmosphere decreased by ~25%, and that the H escape rate increased by a factor of 5, mainly through an increase in upper atmospheric temperature. This significant escape rate variation is comparable to seasonally observed trends but occurred at much shorter timescales. Such solar events would statistically impact extrapolation of martian water loss over time.

Domaines: Physique de l'espace [physics.space-ph]; Physique Atmosphérique et Océanique [physics.ao-ph]

Majd Mayyasi, Dolon Bhattacharyya, John Clarke, Amy Catalano, Mehdi Benna, et al.. Significant Space Weather Impact on the Escape of Hydrogen from Mars. Geophysical Research Letters, 2018, 45 (17), pp.8844-8852. ⟨10.1029/2018GL077727⟩. ⟨insu-01798739⟩