Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production

This is the publisher's version, also available electronically from http://onlinelibrary.wiley.com/doi/10.1002/grl.50222/abstract We examine possible sources of a substantial increase in tree ring 14C measurements for the years AD 774-775. Contrary to claims regarding a coronal mass ejection (C...

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Published in:Geophysical Research Letters
Main Authors: Thomas, Brian C., Melott, Adrian L., Arkenberg, Keith R.
Format: Article in Journal/Newspaper
Language:unknown
Published: American Geophysical Union 2014
Subjects:
Online Access:http://hdl.handle.net/1808/14474
https://doi.org/10.1002/grl.50222
id ftunivkansas:oai:kuscholarworks.ku.edu:1808/14474
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spelling ftunivkansas:oai:kuscholarworks.ku.edu:1808/14474 2023-05-15T16:39:09+02:00 Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production Thomas, Brian C. Melott, Adrian L. Arkenberg, Keith R. 2014-07-03T15:29:12Z http://hdl.handle.net/1808/14474 https://doi.org/10.1002/grl.50222 unknown American Geophysical Union Brian C. Thomas et al. (2013). Terrestrial effects due to possible astrophysical sources of an AD 774-775 increase in 14C production. Geophysical Research Letters 40:41643. http://www.dx.doi.org/10.1002/grl.50222 0094-8276 http://hdl.handle.net/1808/14474 doi:10.1002/grl.50222 orcid:0000-0001-9091-0830 openAccess Solar proton event Ozone carbon-14 Article 2014 ftunivkansas https://doi.org/10.1002/grl.50222 2022-08-26T13:14:56Z This is the publisher's version, also available electronically from http://onlinelibrary.wiley.com/doi/10.1002/grl.50222/abstract We examine possible sources of a substantial increase in tree ring 14C 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. Article in Journal/Newspaper ice core The University of Kansas: KU ScholarWorks Geophysical Research Letters 40 6 1237 1240
institution Open Polar
collection The University of Kansas: KU ScholarWorks
op_collection_id ftunivkansas
language unknown
topic Solar proton event
Ozone
carbon-14
spellingShingle Solar proton event
Ozone
carbon-14
Thomas, Brian C.
Melott, Adrian L.
Arkenberg, Keith R.
Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production
topic_facet Solar proton event
Ozone
carbon-14
description This is the publisher's version, also available electronically from http://onlinelibrary.wiley.com/doi/10.1002/grl.50222/abstract We examine possible sources of a substantial increase in tree ring 14C 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.
format Article in Journal/Newspaper
author Thomas, Brian C.
Melott, Adrian L.
Arkenberg, Keith R.
author_facet Thomas, Brian C.
Melott, Adrian L.
Arkenberg, Keith R.
author_sort Thomas, Brian C.
title Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production
title_short Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production
title_full Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production
title_fullStr Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production
title_full_unstemmed Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production
title_sort terrestrial effects of possible astrophysical sources of an ad 774-775 increase in 14c production
publisher American Geophysical Union
publishDate 2014
url http://hdl.handle.net/1808/14474
https://doi.org/10.1002/grl.50222
genre ice core
genre_facet ice core
op_relation Brian C. Thomas et al. (2013). Terrestrial effects due to possible astrophysical sources of an AD 774-775 increase in 14C production. Geophysical Research Letters 40:41643. http://www.dx.doi.org/10.1002/grl.50222
0094-8276
http://hdl.handle.net/1808/14474
doi:10.1002/grl.50222
orcid:0000-0001-9091-0830
op_rights openAccess
op_doi https://doi.org/10.1002/grl.50222
container_title Geophysical Research Letters
container_volume 40
container_issue 6
container_start_page 1237
op_container_end_page 1240
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