Lethal surface ozone concentrations are possible on habitable zone exoplanets

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Cooke, G. J., Marsh, D. R., Walsh, C., Sainsbury-Martinez, F.
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866929366356721664
author Cooke, G. J.
Marsh, D. R.
Walsh, C.
Sainsbury-Martinez, F.
author_facet Cooke, G. J.
Marsh, D. R.
Walsh, C.
Sainsbury-Martinez, F.
contents Ozone ($\textrm{O}_3$) is important for the survival of life on Earth because it shields the surface from ionising ultraviolet (UV) radiation. However, the existence of $\textrm{O}_3$ in Earth's atmosphere is not always beneficial. Resulting from anthropogenic activity, $\textrm{O}_3$ exists as a biologically harmful pollutant at the surface when it forms in the presence of sunlight and other pollutants. As a strong oxidiser, $\textrm{O}_3$ can be lethal to several different organisms; thus, when assessing the potential habitability of an exoplanet, a key part is determining whether toxic gases could be present at its surface. Using the Whole Atmosphere Community Climate Model version 6 (WACCM6; a three-dimensional chemistry-climate model), twelve atmospheric simulations of the terrestrial exoplanet TRAPPIST-1 e are performed with a variety of $\textrm{O}_2$ concentrations and assuming two different stellar spectra proposed in the literature. Four atmospheric simulations of the exoplanet Proxima Centauri b are also included. Some scenarios for both exoplanets exhibit time-averaged surface $\textrm{O}_3$ mixing ratios exceeding harmful levels of 40 ppbv, with 2200 ppbv the maximum concentration found in the cases simulated. These concentrations are toxic and can be fatal to most life on Earth. In other scenarios $\textrm{O}_3$ remains under harmful limits over a significant fraction of the surface, despite there being present regions which may prove inhospitable. In the case that $\textrm{O}_3$ is detected in a terrestrial exoplanet's atmosphere, determining the surface concentration is an important step when evaluating a planet's habitability.
format Preprint
id arxiv_https___arxiv_org_abs_2405_20167
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Lethal surface ozone concentrations are possible on habitable zone exoplanets
Cooke, G. J.
Marsh, D. R.
Walsh, C.
Sainsbury-Martinez, F.
Earth and Planetary Astrophysics
Ozone ($\textrm{O}_3$) is important for the survival of life on Earth because it shields the surface from ionising ultraviolet (UV) radiation. However, the existence of $\textrm{O}_3$ in Earth's atmosphere is not always beneficial. Resulting from anthropogenic activity, $\textrm{O}_3$ exists as a biologically harmful pollutant at the surface when it forms in the presence of sunlight and other pollutants. As a strong oxidiser, $\textrm{O}_3$ can be lethal to several different organisms; thus, when assessing the potential habitability of an exoplanet, a key part is determining whether toxic gases could be present at its surface. Using the Whole Atmosphere Community Climate Model version 6 (WACCM6; a three-dimensional chemistry-climate model), twelve atmospheric simulations of the terrestrial exoplanet TRAPPIST-1 e are performed with a variety of $\textrm{O}_2$ concentrations and assuming two different stellar spectra proposed in the literature. Four atmospheric simulations of the exoplanet Proxima Centauri b are also included. Some scenarios for both exoplanets exhibit time-averaged surface $\textrm{O}_3$ mixing ratios exceeding harmful levels of 40 ppbv, with 2200 ppbv the maximum concentration found in the cases simulated. These concentrations are toxic and can be fatal to most life on Earth. In other scenarios $\textrm{O}_3$ remains under harmful limits over a significant fraction of the surface, despite there being present regions which may prove inhospitable. In the case that $\textrm{O}_3$ is detected in a terrestrial exoplanet's atmosphere, determining the surface concentration is an important step when evaluating a planet's habitability.
title Lethal surface ozone concentrations are possible on habitable zone exoplanets
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2405.20167