Increase of radiocarbon concentration in tree rings from Kujawy (SE Poland) around AD 774–775

Rakowski, Andrzej; Krąpiec, Marek; Huels, Mathias; Pawlyta, Jacek; Dreves, Alexander; Meadows, John

doi:10.1016/j.nimb.2015.03.035

Cited by 24 publications

(27 citation statements)

References 17 publications

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“…The strongest peak of Δ 14 C, corresponding to the event of AD 775 (called henceforth M12), and another peak in AD 993/4 were measured by Miyake (Miyake et al 2012(Miyake et al , 2013) using 14 C in annually resolved Japanese cedar tree-ring sequences, and M12 has been confirmed by several studies (Usoskin et al 2013;Jull et al 2014;Güttler et al 2015;Rakowski et al 2015;Büntgen et al 2016) including three that showed peaks with slightly different starting times. Data from high-latitude Siberian and Altai (Jull et al 2014;Büntgen et al 2016) record the AD 775 peak but show a Δ 14 C rise beginning one year earlier, and Δ 14 C data in New Zealand kauri (Güttler et al 2015) indicate a peak delayed by half a year.…”

Section: Introductionmentioning

confidence: 72%

Relationship between solar activity and Δ¹⁴C peaks in AD 775, AD 994, and 660 BC

et al. 2017

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ABSTRACT. Since the AD 775 and AD 994 Δ 14 C peak (henceforth M12) was first measured by Miyake et al. (2012Miyake et al. ( , 2013, several possible production mechanisms for these spike have been suggested, but the work of Mekhaldi et al. (2015) shows that a very soft energy spectrum was involved, implying that a strong solar energetic particle (SEP) event (or series of events) was responsible. Here we present Δ 14 C values from AD 721-820 Sequoiadendron giganteum annual tree-ring samples from Sequoia National Park in California, USA, together with Δ 14 C in German oak from 650-670 BC. The AD 721-820 measurements confirm that a sharp Δ 14 C peak exists at AD 775, with a peak height of approximately 15‰ and show that this spike was preceded by several decades of rapidly decreasing Δ 14 C. A sharp peak is also present at 660 BC, with a peak height of about 10‰, and published data ) indicate that it too was preceded by a multi-decadal Δ 14 C decrease, suggesting that solar activity was very strong just prior to both Δ 14 C peaks and may be causally related. During periods of strong solar activity there is increased probability for coronal mass ejection (CME) events that can subject the Earth's atmosphere to high fluencies of solar energetic particles (SEPs). Periods of high solar activity (such as one in October-November 2003) can also often include many large, fast CMEs increasing the probability of geomagnetic storms. In this paper we suggest that the combination of large SEP events and elevated geomagnetic activity can lead to enhanced production of 14 C and other cosmogenic isotopes by increasing the area of the atmosphere that is irradiated by high solar energetic particles.

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Section: Introductionmentioning

confidence: 72%

Relationship between solar activity and Δ¹⁴C peaks in AD 775, AD 994, and 660 BC

et al. 2017

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“…Oak, on the other hand, used by Usoskin et al [2013] and Rakowski et al [2015], is a ring-porous angiosperm (also called hardwood or deciduous tree) [Ladefoged, 1952;Speer, 2010]. Oak, on the other hand, used by Usoskin et al [2013] and Rakowski et al [2015], is a ring-porous angiosperm (also called hardwood or deciduous tree) [Ladefoged, 1952;Speer, 2010].…”

Section: Tree Physiologymentioning

confidence: 99%

“…has since been identified in other high-resolution radiocarbon records from trees, such as German oak [Usoskin et al, 2013], Siberian larch, North American bristlecone pine [Jull et al, 2014], New Zealand kauri [Güttler et al, 2015], and Polish oak [Rakowski et al, 2015], as well as corals [Liu et al, 2014]. has since been identified in other high-resolution radiocarbon records from trees, such as German oak [Usoskin et al, 2013], Siberian larch, North American bristlecone pine [Jull et al, 2014], New Zealand kauri [Güttler et al, 2015], and Polish oak [Rakowski et al, 2015], as well as corals [Liu et al, 2014].…”

Section: Introductionmentioning

confidence: 96%

Cosmic ray event in 994 C.E. recorded in radiocarbon from Danish oak

Fogtmann-Schulz

Østbø

Nielsen

et al. 2017

Geophysical Research Letters

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We present measurements of radiocarbon in annual tree rings from the time period 980–1006 Common Era (C.E.), hereby covering the cosmic ray event in 994 C.E. The new radiocarbon record from Danish oak is based on both earlywood and latewood fractions of the tree rings, which makes it possible to study seasonal variations in 14C production. The measurements show a rapid increase of ∼10‰ from 993 to 994 C.E. in latewood, followed by a modest decline and relatively high values over the ensuing ∼10 years. This rapid increase occurs from 994 to 995 C.E. in earlywood, suggesting that the cosmic ray event most likely occurred during the period between April and June 994 C.E. Our new record from Danish oak shows strong agreement with existing Δ14C records from Japan, thus supporting the hypothesis that the 994 C.E. cosmic ray event was uniform throughout the Northern Hemisphere and therefore can be used as an astrochronological tie point to anchor floating chronologies of ancient history.

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“…Geophysical Research Letters Thereby, with the above magnitudes of R flash , n str , _ N cosm 14 6 C À Á , δ, and σ abs /σ 14 for the initial and moderated neutron spectra, numbers of neutrons per lightning stroke N n1 required to account for 10% (k = 0.1), and a half (k = 0.5) of the observed RPR, at different areas of the globe varies as given in Table 1. Note that the fraction k = 0.1 corresponds to the observed fluctuations in the 14 6 C production (Dorman, 2004, section 17;Lingenfelter, 1963;Pavlov et al, 2013;Rakowski et al, 2015;Suess, 1965;Usoskin et al, 2013).…”

Section: 1002/2017gl075131mentioning

confidence: 96%

Radiocarbon Production by Thunderstorms

Babich

2017

Geophysical Research Letters

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In view of the neutron flux enhancements observed in thunderstorms, a contribution of thunderstorm neutrons to atmospheric radiocarbon (isotope 14 6 C) production is analyzed in connection with the archaeometry. Herein, estimates of neutron fluence per lightning electromagnetic pulse in regions with severe thunderstorm activity, at which a local rate of the 14 6 C production is comparable to the observed rates, are shown to be consistent with the measured magnitudes of thunderstorm neutron fluence. At present, available observations of atmospheric neutron and parent gamma ray flashes correlated with thunderstorms do not allow making final conclusions about thunderstorm contributions to 14 6 C production. For this, numerous studies of high-energy phenomena in thunderstorms are required, especially in the tropical belt where the thunderstorm activity is especially severe and where the 14 6 C production by galactic cosmic rays is almost independent of the solar activity disturbing the Earth's magnetic field shielding the Earth from cosmic rays. Plain Language Summary Decay of radiocarbon accumulated in fossil biota is widely used in archaeometry. A capture by atmospheric nitrogen nuclei of neutrons, produced by cosmic rays, is causal to the radiocarbon production. In view of that thunderstorms produce neutrons their contribution in the radiocarbon production is analyzed. In regions with severe thunderstorm activity, evaluated neutron numbers per unit area (fluence) per lightning required for a rate of the radiocarbon production by thunderstorms to be comparable to the measured rate magnitudes are consistent with the measured magnitudes of thunderstorm neutron fluence. Available data on thunderstorm neutrons and parent to them gamma ray flashes do not allow making final conclusion about the thunderstorm deposition in the radiocarbon production. For this, numerous observations are required, especially in tropics where the thunderstorm activity is extremely strong and where the radiocarbon production is almost independent of the solar activity disturbing the Earth's magnetic field shielding the Earth from cosmic rays.

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Increase of radiocarbon concentration in tree rings from Kujawy (SE Poland) around AD 774–775

Cited by 24 publications

References 17 publications

Relationship between solar activity and Δ¹⁴C peaks in AD 775, AD 994, and 660 BC

Relationship between solar activity and Δ¹⁴C peaks in AD 775, AD 994, and 660 BC

Cosmic ray event in 994 C.E. recorded in radiocarbon from Danish oak

Radiocarbon Production by Thunderstorms

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Increase of radiocarbon concentration in tree rings from Kujawy (SE Poland) around AD 774–775

Cited by 24 publications

References 17 publications

Relationship between solar activity and Δ14C peaks in AD 775, AD 994, and 660 BC

Relationship between solar activity and Δ14C peaks in AD 775, AD 994, and 660 BC

Cosmic ray event in 994 C.E. recorded in radiocarbon from Danish oak

Radiocarbon Production by Thunderstorms

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Product

Resources

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Relationship between solar activity and Δ¹⁴C peaks in AD 775, AD 994, and 660 BC

Relationship between solar activity and Δ¹⁴C peaks in AD 775, AD 994, and 660 BC