The Nice Oxidation Occasion was a interval throughout which Earth’s atmospheric oxygen (O2) concentrations elevated from ∼10−5 occasions its current atmospheric degree (PAL) to close trendy ranges, marking the beginning of the Proterozoic geological eon 2.4 billion years in the past.
Utilizing WACCM6, an Earth System Mannequin, we simulate the environment of Earth-analogue exoplanets with O2 mixing ratios between 0.1% and 150% PAL. Utilizing these simulations, we calculate the reflection/emission spectra over a number of orbits utilizing the Planetary Spectrum Generator.
We spotlight how observer angle, albedo, chemistry, and clouds have an effect on the simulated observations. We present that inter-annual local weather variations, in addition to short-term variations because of clouds, could be noticed in our simulated atmospheres with a telescope idea resembling LUVOIR or HabEx.
Annual variability and seasonal variability can change the planet’s mirrored flux (together with the mirrored flux of key spectral options resembling O2 and H2O) by as much as components of 5 and 20, respectively, for a similar orbital part.
This variability is finest noticed with a high-throughput coronagraph. For instance, HabEx (4 m) with a starshade performs as much as an element of two occasions higher than a LUVOIR B (6 m) fashion telescope. The variability and signal-to-noise ratio of some spectral options relies upon non-linearly on atmospheric O2 focus.
That is brought on by temperature and chemical column depth variations, in addition to usually elevated liquid and ice cloud content material for atmospheres with O2 concentrations of
Gregory Cooke (1), Dan Marsh (1 and a couple of), Catherine Walsh (1), Sarah Rugheimer (3 and 4), Geronimo Villanueva (5) ((1) College of Physics and Astronomy, College of Leeds, UK, ( 2) Nationwide Heart for Atmospheric Analysis, Boulder, USA, (3) College Oxford, Atmospheric, Oceanic, and Planetary Physics Division, UK, (4) Dept of Physics and Astronomy, York College, Canada, (5) NASA Goddard Area Flight Heart, Photo voltaic System Exploration Division, USA)
Feedback: 14 pages, 7 figures. Accepted for publication in MNRAS
Topics: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2209.07566 [astro-ph.EP] (or arXiv:2209.07566v1 [astro-ph.EP] for this model)
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Submission historical past
From: Gregory Cooke
[v1] Thu, 15 Sep 2022 19:10:00 UTC (9,395 KB)