TRAPPIST-1

3D Simulations Of TRAPPIST-1e With Varying CO2, CH4 And Haze Profiles

By Keith Cowing

Status Report

astro-ph.EP

March 12, 2024

Filed under astro-ph.EP, atmosphere, general circulation model, Haze, TRAPPIST 1-e, TRAPPIST-1

3D Simulations Of TRAPPIST-1e With Varying CO2, CH4 And Haze Profiles — Contour plot of surface temperature of the simulations, overlapping with arrows indicating the direction and magnitude of the surface wind.. a, b and c show the noAER simulations with pCO2 = 100, 3,000 and 20,000 Pa (pCH4 fixed at 0 Pa). d, e and f show the noAER simulations with CH4/CO2 = 0.02, 0.04 and 0.1 (pCO2 fixed at 20,000 Pa). g, h and i show the AER simulations with CH4/CO2 = 0.1, 0.125 and 0.175 (pCO2 fixed at 3,000 Pa). The liquid-water region, defined as the area with the surface temperature larger than 273 K and can maintain liquid water on the surface, is denoted with a white line. The wind structure of each simulation is also denoted, with the single jet structure denoted as “SJ” and the double jet structure denoted as “DJ”. — astro-ph.EP

Using a 3D General Circulation Model, the Unified Model, we present results from simulations of a tidally-locked TRAPPIST-1e with varying carbon dioxide CO₂ and methane CH₄ gas concentrations, and their corresponding prescribed spherical haze profiles.

Our results show that the presence of CO₂ leads to a warmer atmosphere globally due to its greenhouse effect, with the increase of surface temperature on the dayside surface reaching up to ~14.1 K, and on the nightside up to ~21.2 K. Increasing presence of CH₄ first elevates the surface temperature on the dayside, followed by a decrease due to the balance of tropospheric warming and stratospheric cooling.

A thin layer of haze, formed when the partial pressures of CH₄ to CO₂ (pCH₄/pCO₂) = 0.1, leads to a dayside warming of ~4.9K due to a change in the water vapour H₂O distribution. The presence of a haze layer that formed beyond the ratio of 0.1 leads to dayside cooling. The haze reaches an optical threshold thickness when pCH₄/pCO₂ ~0.4 beyond which the dayside mean surface temperature does not vary much. The planet is more favourable to maintaining liquid water on the surface (mean surface temperature above 273.15 K) when pCO₂ is high, pCH₄ is low and the haze layer is thin.

The effect of CO₂, CH₄ and haze on the dayside is similar to that for a rapidly-rotating planet. On the contrary, their effect on the nightside depends on the wind structure and the wind speed in the simulation.

Mei Ting Mak, Denis Sergeev, Nathan Mayne, Nahum Banks, Jake Eager-Nash, James Manners, Giada Arney, Eric Hebrard, Krisztian Kohary

Comments: 17 pages, 16 figures, 2 tables
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2403.06928 [astro-ph.EP] (or arXiv:2403.06928v1 [astro-ph.EP] for this version)
Submission history
From: Mei Ting Mak
[v1] Mon, 11 Mar 2024 17:17:01 UTC (3,252 KB)
https://arxiv.org/abs/2403.06928
Astrobiology, Astrochemistry,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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