Thomas Brian C, Goracke Byron D
Department of Physics and Astronomy, Washburn University , Topeka, Kansas.
Astrobiology. 2016 Jan;16(1):1-6. doi: 10.1089/ast.2015.1311. Epub 2016 Jan 8.
Astrophysical ionizing radiation events such as supernovae, gamma-ray bursts, and solar proton events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in solar UV radiation at Earth's surface and in the upper levels of the ocean. Other work has also considered the potential impact of nitric acid rainout, concluding that no significant threat is likely. Not yet studied to date is the potential impact of ozone produced in the lower atmosphere following an ionizing radiation event. Ozone is a known irritant to organisms on land and in water and therefore may be a significant additional hazard. Using previously completed atmospheric chemistry modeling, we examined the amount of ozone produced in the lower atmosphere for the case of a gamma-ray burst and found that the values are too small to pose a significant additional threat to the biosphere. These results may be extended to other ionizing radiation events, including supernovae and extreme solar proton events.
诸如超新星爆发、伽马射线暴和太阳质子事件等天体物理电离辐射事件，主要通过平流层臭氧的消耗以及随后地球表面和海洋上层太阳紫外线辐射的增加，被认为是对地球上生命的潜在威胁。其他研究也考虑了硝酸雨沉降的潜在影响，得出不太可能构成重大威胁的结论。迄今为止尚未研究的是电离辐射事件后低层大气中产生的臭氧的潜在影响。臭氧是陆地和水中生物已知的刺激物，因此可能是一个重大的额外危害。利用先前完成的大气化学模型，我们研究了伽马射线暴情况下低层大气中产生的臭氧量，发现其数值太小，不会对生物圈构成重大的额外威胁。这些结果可能适用于其他电离辐射事件，包括超新星爆发和极端太阳质子事件。
