2013/02/07 by Brian C. Thomas, Adrian L. Melott, Keith R. Arkenberg +2 · 63 citations
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Astro and Planetary Science #Atmosphere (unit) #Coronal mass ejection #Event (particle physics) #Extinction event #Magnitude (astronomy) #Ozone #Solar and Space Plasma Dynamics #Solar energetic particles #Solar flare #Stellar, planetary, and galactic studies #astro-ph.SR #physics.ao-ph #physics.geo-ph #physics.space-ph #q-bio.PE
paper · pdf · doi:10.1002/grl.50222
published in Geophysical Research Letters 40(6), 1237-1240 (American Geophysical Union) · In press at Geophysical Research Letters
arxiv created 2013/02/07 · openalex publication_date 2013/02/12 · arxiv updated 2015/03/26 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We examine possible sources of a substantial increase in tree ring 14 C measurements for the years AD 774‐775. Contrary to claims regarding a coronal mass ejection (CME), the required CME energy is not several orders of magnitude greater than known solar events. We consider solar proton events (SPEs) with three different fluences and two different spectra. The data may be explained by an event with fluence about one order of magnitude beyond the October 1989 SPE. Two hard spectrum cases considered here result in moderate ozone depletion, so no mass extinction is implied, though we do predict increases in erythema and damage to plants from enhanced solar UV. We are able to rule out an event with a very soft spectrum that causes severe ozone depletion and subsequent biological impacts. Nitrate enhancements are consistent with their apparent absence in ice core data. The modern technological implications of such an event may be extreme, and considering recent confirmation of superflares on solar‐type stars, this issue merits attention.