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

@article{Thomas2013TerrestrialEO,
  title={Terrestrial effects of possible astrophysical sources of an AD 774‐775 increase in 14C production},
  author={Brian C. Thomas and Adrian L. Melott and Keith R. Arkenberg and Brock R. Snyder},
  journal={Geophysical Research Letters},
  year={2013},
  volume={40},
  pages={1237-1240}
}
[1] 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… 

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Two radiocarbon excursions (AD 774–775 and AD 993–994) occurred due to an increase of incoming cosmic rays on a short timescale. The most plausible cause of these events is considered to be extreme
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References

SHOWING 1-10 OF 49 REFERENCES
A signature of cosmic-ray increase in ad 774–775 from tree rings in Japan
TLDR
It is argued that neither a solar flare nor a local supernova is likely to have been responsible for the increase in 14C concentrations in tree rings of Japanese cedar trees, and the data are consistent with the decadal IntCal 14C data from North American and European trees.
A Galactic short gamma-ray burst as cause for the 14C peak in AD 774/5
In the last 3000 yr, one significant and rapid increase in the concentration of 14 Ci n tree rings was observed; it corresponds to a γ -ray energy input of 7 × 10 24 erg at Earth within up to one
Occurrence of extreme solar particle events: Assessment from historical proxy data
The probability of occurrence of extreme solar particle events (SPEs) with proton fluence (>30 MeV) F 30 ≥ 1010 cm–2 is evaluated based on data on the cosmogenic isotopes 14C and 10Be in terrestrial
Climatic and biogeochemical effects of a galactic gamma ray burst
TLDR
The results support the hypothesis that the characteristics of the Late Ordovician mass extinction are consistent with GRB initiation, and show the first detailed computation of two other significant effects.
Solar cosmic ray events for the period 1561–1994: 1. Identification in polar ice, 1561–1950
The geophysical significance of the thin nitrate-rich layers that have been found in both Arctic and Antarctic firn and ice cores, dating from the period 1561–1991, is examined in detail. It is shown
Causes of an ad 774–775 14C increase
TLDR
It is found that the coronal mass ejection energy based on 14C production is much smaller than claimed in ref. 1, but still substantially larger than the maximum historical Carrington Event of 1859.
Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage
TLDR
This work focuses on gamma-ray bursts (Thorsett 1995; Scalo and Wheeler 2002), a proposed causal agent for the end-Ordovician extinction, a threat approximately competitive with, for example, that of nearby supernovae.
Atmospheric impact of the Carrington event solar protons
[1] The Carrington event of August/September 1859 was the most significant solar proton event (SPE) of the last 450 years, about four times larger than the solar proton fluence of the largest event
Terrestrial Consequences of Spectral and Temporal Variability in Ionizing Photon Events
TLDR
The effect of many astrophysical events causing atmospheric ionization can be approximated without including time development by generalizing atmospheric computations to include a broad range of peak photon energies and investigating the effect of burst duration.
Estimating the frequency of extremely energetic solar events, based on solar, stellar, lunar, and terrestrial records
[1] The most powerful explosions on the Sun – in the form of bright flares, intense storms of solar energetic particles (SEPs), and fast coronal mass ejections (CMEs) – drive the most severe
...
1
2
3
4
5
...