Climate Change Data Portal
| DOI | 10.1016/j.epsl.2021.116818 |
| Photochemical modelling of atmospheric oxygen levels confirms two stable states | |
| Gregory B.S.; Claire M.W.; Rugheimer S. | |
| 发表日期 | 2021 |
| ISSN | 0012821X |
| 卷号 | 561 |
| 英文摘要 | Various proxies and numerical models have been used to constrain O2 levels over geological time, but considerable uncertainty remains. Previous investigations using 1-D photochemical models have predicted how O3 concentrations vary with assumed ground-level O2 concentrations, and indicate how the ozone layer might have developed over Earth history. These classic models have utilised the numerical simplification of fixed mixing ratio boundary conditions. Critically, this modelling assumption requires verification that predicted fluxes of biogenic and volcanic gases are realistic, but also that the resulting steady states are in fact stable equilibrium solutions against trivial changes in flux. Here, we use a 1-D photochemical model with fixed flux boundary conditions to simulate the effects on O3 and O2 concentrations as O2 (and CH4) fluxes are systematically varied. Our results suggest that stable equilibrium solutions exist for trace- and high-O2/O3 cases, separated by a region of instability. In particular, the model produces few stable solutions with ground O2 mixing ratios between 6×10−7 and 2×10−3 (3×10−6 and 1% of present atmospheric levels). A fully UV-shielding ozone layer only exists in the high-O2 states. Our atmospheric modelling supports prior work suggesting a rapid bimodal transition between reducing and oxidising conditions and proposes Proterozoic oxygen levels higher than some recent proxies suggest. We show that the boundary conditions of photochemical models matter, and should be chosen and explained with care. © 2021 The Author(s) |
| 关键词 | 1-D photochemical modellingatmospheric evolutionmethaneoxygenozoneProterozoic |
| 英文关键词 | Mixing; Ozone; Ozone layer; Atmospheric levels; Atmospheric modelling; Atmospheric oxygen; Flux boundary conditions; Photochemical modeling; Photochemical modelling; Photochemical models; Stable equilibrium; Boundary conditions; boundary condition; concentration (composition); methane; mixing ratio; one-dimensional modeling; oxygen; ozone; paleoatmosphere; photochemistry; Proterozoic |
| 语种 | 英语 |
| 来源期刊 | Earth and Planetary Science Letters
 |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/203107 |
| 作者单位 | School of Earth and Environmental Sciences, University of St Andrews, St Andrews, KY16 9AL, United Kingdom; Centre for Exoplanet Sciences, University of St Andrews, St Andrews, KY16 9AL, United Kingdom; Blue Marble Space Institute of Science, 1001 4th Ave, Suite 3201, Seattle, WA 98154, United States; Department of Physics, University of Oxford, Oxford, OX1 3PU, United Kingdom |
| 推荐引用方式 GB/T 7714 | Gregory B.S.,Claire M.W.,Rugheimer S.. Photochemical modelling of atmospheric oxygen levels confirms two stable states[J],2021,561. |
| APA | Gregory B.S.,Claire M.W.,&Rugheimer S..(2021).Photochemical modelling of atmospheric oxygen levels confirms two stable states.Earth and Planetary Science Letters,561. |
| MLA | Gregory B.S.,et al."Photochemical modelling of atmospheric oxygen levels confirms two stable states".Earth and Planetary Science Letters 561(2021). |
| 条目包含的文件 | 条目无相关文件。 | |||||
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
