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The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
ABSTRACT Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a…
A signature of cosmic-ray increase in ad 774–775 from tree rings in Japan
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.
Another rapid event in the carbon-14 content of tree rings.
- F. Miyake, K. Masuda, Toshio Nakamura
- Environmental Science, PhysicsNature communications
- 23 April 2013
New ( 14)C measurements from AD 822 to 1020, and the discovery of a second rapid increase of (14)C content from AD 992 to 993 are reported, suggesting that solar activity is a plausible cause of the (14), and it is highly possible that these events have the same origin.
Verification of the Cosmic-Ray Event in AD 993–994 by Using a Japanese Hinoki Tree
A rapid yearly increase in the radiocarbon content has been detected for the period from AD 993 to 994. However, this event is supported by the 14C measurements of only one cedar tree sample, and…
Atmospheric impacts of the strongest known solar particle storm of 775 AD
- T. Sukhodolov, I. Usoskin, R. Traversi
- Environmental Science, PhysicsScientific reports
- 28 March 2017
It is shown that such a severe SEP event is able to perturb the polar stratosphere for at least one year, leading to regional changes in the surface temperature during northern hemisphere winters, and adds to prior conclusions that any nitrate deposition signal from SEP events remains too weak to be detected in ice cores.
Lengths of Schwabe cycles in the seventh and eighth centuries indicated by precise measurement of carbon‐14 content in tree rings
Radiocarbon (14C) is produced in the atmosphere by galactic cosmic rays, which are modulated by solar magnetic activity. Its content in tree rings is retained and provides a record of past cosmic ray…
Tree rings reveal globally coherent signature of cosmogenic radiocarbon events in 774 and 993 CE
The identification of distinct 14C excursions in 484 individual tree rings enable the authors to confirm the dating of 44 dendrochronologies from five continents, and suggest a global exposure to strong solar proton radiation.
Large 14C excursion in 5480 BC indicates an abnormal sun in the mid-Holocene
- F. Miyake, A. Jull, Toshio Nakamura
- Environmental Science, PhysicsProceedings of the National Academy of Sciences
- 18 January 2017
The possible causes of the mid-Holocene 14C variation of the 5480 BC event are an unknown phase of grand solar minimum, or a combination of successive solar proton events and a normal grand solar Minimum.
Cosmic ray event of A.D. 774–775 shown in quasi‐annual 10Be data from the Antarctic Dome Fuji ice core
14C content in tree rings and 10Be concentration records in polar ice core provide information about past cosmic ray intensities. The A.D. 774–775 cosmic ray event has been identified by 14C…
Radiocarbon Ages of Annual Rings from Japanese Wood: Evident Age Offset Based on IntCal09
- Toshio Nakamura, K. Masuda, F. Miyake, Kentaro Nagaya, Takahiro Yoshimitsu
- Environmental ScienceRadiocarbon
- 9 May 2013
To investigate the radiocarbon concentration of atmospheric CO2 over the past few millennia in Japan, we measured the 14C age of annual rings from 3 Japanese trees with calendar dates ranging from…