Supernovae and Single-Year Anomalies in the Atmospheric Radiocarbon Record

Dee, Michael W.; Pope, Benjamin; Miles, Daniel; Manning, Sturt W.; Miyake, Fusa

doi:10.1017/rdc.2016.50

Cited by 29 publications

(32 citation statements)

References 44 publications

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“…The deviation in terms of standard deviations (dev σ) is calculated as ( 14 C Museum and prepared and analyzed at AARAMS like the wood pieces used in this study. Some disagreements between the AD 1000 dataset of this study and the data by Fogtmann-Schulz et al 2017 1995Dee et al 2017Güttler et al 2013Menjo et al 2005Miyake et al 2013Miyake et al 2014 IntCal13 T−filter F=3…”

Section: Methodscontrasting

confidence: 53%

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New Single-Year Radiocarbon Measurements Based on Danish oak Covering the Periods AD 692–790 and 966–1057

et al. 2019

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Single-year measurements of radiocarbon (14C) in tree rings have led to the discovery of rapid cosmic-ray events as well as longer lasting anomalies, which have given new insights into the Sun’s behavior in the past. Here, we present two new single-year 14C records based on Danish oak that span the periods AD 692–790 and 966–1057, respectively, and consequently include the two rapid cosmic-ray events in AD 775 and 994. The new data are presented along with relevant information on the dendrochronological dating of the wood pieces, implying that these new measurements may contribute towards generating the next international calibration curve. The new data covering the AD 966–1057 period suggest that the increase in atmospheric 14C associated with the cosmic-ray event in AD 994 actually occurred in AD 993, i.e. one year earlier than the year reported in Fogtmann-Schulz et al. (2017) based on oak from southern Denmark. Careful reanalysis of the dendrochronology that underpins the new 14C records based on oak material from southern Denmark reveals that the cosmic-ray event reported in Fogtmann-Schulz et al. (2017) actually took place in AD 993.

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Section: Methodscontrasting

confidence: 53%

“…records have also been used to search for similar excursions in the atmospheric 14 C content that may be caused by near-Earth supernova explosions, but so far no clear indications of such an event have been found (Damon et al 1995;Menjo et al 2005;Dee et al 2017).…”

Section: Introductionmentioning

confidence: 99%

New Single-Year Radiocarbon Measurements Based on Danish oak Covering the Periods AD 692–790 and 966–1057

et al. 2019

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“…If M12 was caused by a supernova, a candidate supernova should exist, but observations spanning several hundred years before AD 775 record no such event. Supernovae emit both high-energy particles and gamma rays, but high-energy particles from supernova have sufficient energy spread that extended arrival times spanning at least 10 yr would be expected (Gehrels 2003;Dee et al 2017) *Corresponding author. Email: jsouthon@uci.edu.…”

Section: Introductionmentioning

confidence: 99%

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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“…Recent research has shown that analysis of cosmogenic isotopes may be the only available proxy for historic extreme SEP events (Usoskin et al, 2006;Miyake et al, 2012Miyake et al, , 2013Usoskin et al, 2013;Herbst et al, 2015;McCracken & Beer, 2015;Dee et al, 2016). This would be a hugely valuable data source in constraining the limits of extreme SEP events, which have quite poor statistics over the space age , and are critical for assessing the hazards and risks to our continuing exploration and development of the solar system (Cannon et al, 2013), especially for manned missions.…”

Section: Discussionmentioning

confidence: 99%

“…It has also been argued, both through observations and physical modelling, that extreme SEP events may measurably perturb the 14 C and 10 Be cosmogenic isotope records (Usoskin et al, 2006;Miyake et al, 2012Miyake et al, , 2013Usoskin et al, 2013;Herbst et al, 2015;McCracken & Beer, 2015;Dee et al, 2016). Therefore, cosmogenic isotopes may provide the only viable proxy record for historic SEP fluxes.…”

Section: Introductionmentioning

confidence: 99%

What can the annual ¹⁰Be solar activity reconstructions tell us about historic space weather?

Barnard

McCracken²,

Owens

et al. 2018

J. Space Weather Space Clim.

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-Context: Cosmogenic isotopes provide useful estimates of past solar magnetic activity, constraining past space climate with reasonable uncertainty. Much less is known about past space weather conditions. Recent advances in the analysis of 10 Be by McCracken & Beer (2015, Sol Phys 290: 305-3069) (MB15) suggest that annually resolved 10 Be can be significantly affected by solar energetic particle (SEP) fluxes. This poses a problem, and presents an opportunity, as the accurate quantification of past solar magnetic activity requires the SEP effects to be determined and isolated, whilst doing so might provide a valuable record of past SEP fluxes. Aims: We compare the MB15 reconstruction of the heliospheric magnetic field (HMF), with two independent estimates of the HMF derived from sunspot records and geomagnetic variability. We aim to quantify the differences between the HMF reconstructions, and speculate on the origin of these differences. We test whether the differences between the reconstructions appear to depend on known significant space weather events. Methods: We analyse the distributions of the differences between the HMF reconstructions. We consider how the differences vary as a function of solar cycle phase, and, using a Kolmogorov-Smirnov test, we compare the distributions under the two conditions of whether or not large space weather events were known to have occurred. Results: We find that the MB15 reconstructions are generally marginally smaller in magnitude than the sunspot and geomagnetic HMF reconstructions. This bias varies as a function of solar cycle phase, and is largest in the declining phase of the solar cycle. We find that MB15's excision of the years with very large ground level enhancement (GLE) improves the agreement of the 10 Be HMF estimate with the sunspot and geomagnetic reconstructions. We find no statistical evidence that GLEs, in general, affect the MB15 reconstruction, but this analysis is limited by having too few samples. We do find evidence that the MB15 reconstructions appear statistically different in years with great geomagnetic storms.

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Supernovae and Single-Year Anomalies in the Atmospheric Radiocarbon Record

Cited by 29 publications

References 44 publications

New Single-Year Radiocarbon Measurements Based on Danish oak Covering the Periods AD 692–790 and 966–1057

New Single-Year Radiocarbon Measurements Based on Danish oak Covering the Periods AD 692–790 and 966–1057

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

What can the annual ¹⁰Be solar activity reconstructions tell us about historic space weather?

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Supernovae and Single-Year Anomalies in the Atmospheric Radiocarbon Record

Cited by 29 publications

References 44 publications

New Single-Year Radiocarbon Measurements Based on Danish oak Covering the Periods AD 692–790 and 966–1057

New Single-Year Radiocarbon Measurements Based on Danish oak Covering the Periods AD 692–790 and 966–1057

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

What can the annual 10Be solar activity reconstructions tell us about historic space weather?

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Product

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

What can the annual ¹⁰Be solar activity reconstructions tell us about historic space weather?