Mars

A Systematic Study Of Hot Oxygen Production And Escape From Martian Atmosphere In Response To Enhanced EUV Irradiance From Solar Flares

By Keith Cowing
Status Report
astro-ph.SR
June 30, 2025
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A Systematic Study Of Hot Oxygen Production And Escape From Martian Atmosphere In Response To Enhanced EUV Irradiance From Solar Flares
Pictorial representation of the atmospheric layers of Mars. This purpose of this figure is to show the integrated nature of the planetary atmosphere and re-emphasizes the need to study these coupling processes. — astro-ph.SR

The study of the evolution of Martian atmosphere and its response to EUV irradiation is an extremely important topic in planetary science. One of the dominant effects of atmospheric losses is the photochemical escape of atomic oxygen from Mars.

Increasing the magnitude of the irradiation changes the response of the atmosphere. The purpose of the current paper is to analyze the effects of enhanced EUV irradiation on the escape rates of oxygen atoms.

We have used the solar flare of 2017 September 10 as the baseline flare intensity and varied the intensity of the flare from a factor of 3 up to 10 times the baseline flare. We see an increase in the escape flux by 40% for flares up to 5x the intensity of the baseline flare.

However, beyond this point, the increase in escape flux tapers off, reaching only about 17% above the baseline. At 10x the baseline flare intensity, the escape flux decreases by nearly 25% compared to the escape rate of the original flare. We also found that the total escape amount of hot O peaks at 7x the original flare intensity.

Additionally, we have studied the effects of the time scales over which the flare energy is delivered. We find that energy dissipative processes like radiative cooling and thermal collisions do not come into play instantaneously. The escape flux from higher intensity flares dominate initially, but as time progresses, energy dissipative processes have a significant effect on the escape rate.

Chirag Rathi, Dimitra Atri, Dattaraj B. Dhuri

Comments: 11 pages, 7 figures
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2506.20337 [astro-ph.SR] (or arXiv:2506.20337v1 [astro-ph.SR] for this version)
https://doi.org/10.48550/arXiv.2506.20337
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Related DOI:
https://doi.org/10.3847/PSJ/ade708
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Submission history
From: Chirag Rathi
[v1] Wed, 25 Jun 2025 11:48:01 UTC (1,141 KB)
https://arxiv.org/abs/2506.20337
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