DOI: 10.1038/ngeo2719
论文题名: Prebiotic chemistry and atmospheric warming of early Earth by an active young Sun
作者: Airapetian V.S. ; Glocer A. ; Gronoff G. ; Hébrard E. ; Danchi W.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2016
卷: 9, 期: 6 起始页码: 452
结束页码: 455
语种: 英语
Scopus关键词: atmospheric chemistry
; carbon dioxide
; coronal mass ejection
; early Earth
; greenhouse gas
; magnetohydrodynamics
; magnetosphere
; methane
; nitrogen fixation
; nitrous oxide
; ultraviolet radiation
; warming
英文摘要: Nitrogen is a critical ingredient of complex biological molecules. Molecular nitrogen, however, which was outgassed into the Earth's early atmosphere, is relatively chemically inert and nitrogen fixation into more chemically reactive compounds requires high temperatures. Possible mechanisms of nitrogen fixation include lightning, atmospheric shock heating by meteorites, and solar ultraviolet radiation. Here we show that nitrogen fixation in the early terrestrial atmosphere can be explained by frequent and powerful coronal mass ejection events from the young Sun - so-called superflares. Using magnetohydrodynamic simulations constrained by Kepler Space Telescope observations, we find that successive superflare ejections produce shocks that accelerate energetic particles, which would have compressed the early Earth's magnetosphere. The resulting extended polar cap openings provide pathways for energetic particles to penetrate into the atmosphere and, according to our atmospheric chemistry simulations, initiate reactions converting molecular nitrogen, carbon dioxide and methane to the potent greenhouse gas nitrous oxide as well as hydrogen cyanide, an essential compound for life. Furthermore, the destruction of N2, CO2 and CH4 suggests that these greenhouse gases cannot explain the stability of liquid water on the early Earth. Instead, we propose that the efficient formation of nitrous oxide could explain a warm early Earth. © 2016 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105990
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD, United States; Science Systems and Application, Inc., NASA Langley Research Center, Hampton, VA, United States; NASA Postdoctoral Program, Universities Space Research Association, Columbia, MD, United States
Recommended Citation:
Airapetian V.S.,Glocer A.,Gronoff G.,et al. Prebiotic chemistry and atmospheric warming of early Earth by an active young Sun[J]. Nature Geoscience,2016-01-01,9(6)