Climatic and Biogeochemical Effects of a Galactic Gamma-Ray Burst
Abstract
It is likely that one or more gamma-ray bursts within our galaxy have strongly irradiated the Earth in the last Gy. This produces significant atmospheric ionization and dissociation, resulting in ozone depletion and DNA-damaging ultraviolet solar flux reaching the surface for up to a decade. Here we show the first detailed computation of two other significant effects. Visible opacity of NO2 is sufficient to reduce solar energy at the surface up to a few percent, with the greatest effect at the poles, which may be sufficient to initiate glaciation. Rainout of dilute nitric acid is could have been important for a burst nearer than our conservative nearest burst. These results support the hypothesis that the characteristics of the late Ordovician mass extinction are consistent with GRB initiation.
Keywords
Cite
@article{arxiv.astro-ph/0503625,
title = {Climatic and Biogeochemical Effects of a Galactic Gamma-Ray Burst},
author = {Adrian L. Melott and Brian C. Thomas and Daniel P. Hogan and Larissa M. Ejzak and Charles H. Jackman},
journal= {arXiv preprint arXiv:astro-ph/0503625},
year = {2007}
}
Comments
12 pages, 2 figures, in press at Geophysical Research Letters. Minor revisions, including details on falsifying the hypothesis