3D Modeling of Supersaturated H2O/H2O2 on Early Mars Climate During the Noachia

EPSC Abstracts Vol. 15, EPSC2021-302, 2021, updated on 30 Sep 2021 https://doi.org/10.5194/epsc2021-302 Europlanet Science Congress 2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License.

3D Modeling of Supersaturated H2O/H2O2 on Early Mars Climate during the Noachia

Antony Delavois1, François Forget1, Martin Turbet2, and Ehouarn Millour1 1Laboratoire Météorologie Dynamique, Institut Pierre Simon Laplace, Paris, France 2Observatoire Astronomique de l’Université de Genève, Chemin Pegasi 51, 1290 Sauverny,Switzerland

The climate of Mars during its first billion years is one of the most intriguing question in our understanding of the Solar System. The planet was host of a large amount of liquid water flowing on the surface throughout the Noachian era, approximatively 4Gya. Geomorphological observations is the main evidence for liquid water since valley networks and lakes are still visible on the surface, although dry nowadays.

Different studies have tried to reproduce the conditions that may have occured on the planet, trying to find an atmospheric process or composition that could solve the Faint Young Sun Paradox. Theses modeling studies, through the use of 3-dimensional Global Climate Models struggled to warm sufficiently the past climate of Mars, even considering different greenhouse gases, the role of clouds, meteoritic impact or even volcanism (XXX). However, the presence of H2 could be an interesting solution for a sustainable warming as some recent studies suggest (Turbet and Forget, 2021). Another recent study (Ito et al. 2020) suggested that H2O2 might be a convincing candidate but has to be in high supersaturation ratio in the atmosphere, even though it only used a simplified 1D model and relatively high supersaturation levels.

We try here to explore more in detail the scenario of supersaturated H2O2 and H2O, that also might be a specy able to provide a sufficient global warming under supersaturated conditions or through the formation of high altitude clouds. Since H2O is the major source of H2O2 in the atmosphere, it is important to assess whether the H2O content in the atmosphere is enough to provide high quantities of H2O2. We also try to constrain the theoritical supersaturation level of H2O/H2O2 that will allow the warming of the climate above 273K, but with a detailled 3D GCM simulation. Even if we do not tackle the question whether the supersaturation hypothesis is realistic or not, these results give a better understanding of what would be Early Mars' climate under such conditions.