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Solar Activity of the Past 100 Years Inferred From 10Be in Ice Cores—Implications for Long-Term Solar Activity Reconstructions

Zheng, Minjie LU ; Adolphi, Florian LU ; Sjolte, Jesper LU orcid ; Aldahan, Ala ; Possnert, Göran ; Wu, Mousong LU ; Chen, Peng LU and Muscheler, Raimund LU orcid (2021) In Geophysical Research Letters 48(4).
Abstract

Differences between 10Be records from Greenland and Antarctica over the last 100 years have led to different conclusions about past changes in solar activity. The reasons for this disagreement remain unresolved. We analyze a seasonally resolved 10Be record from a firn core (North Greenland Eemian Ice Drilling [NEEM] ice core project) in Northwestern Greenland for 1887–2002. By comparing the NEEM data to 10Be data from the NGRIP and Dye3 ice cores, we find that the Dye3 data after 1958 are significantly lower. These low values lead to a normalization problem in solar reconstructions when connecting 10Be variations to modern observations. Excluding these data strongly reduces the differences... (More)

Differences between 10Be records from Greenland and Antarctica over the last 100 years have led to different conclusions about past changes in solar activity. The reasons for this disagreement remain unresolved. We analyze a seasonally resolved 10Be record from a firn core (North Greenland Eemian Ice Drilling [NEEM] ice core project) in Northwestern Greenland for 1887–2002. By comparing the NEEM data to 10Be data from the NGRIP and Dye3 ice cores, we find that the Dye3 data after 1958 are significantly lower. These low values lead to a normalization problem in solar reconstructions when connecting 10Be variations to modern observations. Excluding these data strongly reduces the differences between solar reconstructions over the last 2,000 years based on Greenland and Antarctic 10Be data. Furthermore, 10Be records from polar regions and group sunspot numbers do not support a substantial increase in solar activity for the 1937–1950 period as proposed by previous extensions of the neutron monitor data.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Dye3, ice core, NEEM, neutron monitor data, seasonally resolved Be, solar reconstructions
in
Geophysical Research Letters
volume
48
issue
4
article number
e2020GL090896
publisher
American Geophysical Union (AGU)
external identifiers
  • scopus:85101498734
ISSN
0094-8276
DOI
10.1029/2020GL090896
language
English
LU publication?
yes
id
fb72753c-434d-4162-aa02-8ba2699a4519
date added to LUP
2021-12-27 08:12:36
date last changed
2023-02-21 10:07:31
@article{fb72753c-434d-4162-aa02-8ba2699a4519,
  abstract     = {{<p>Differences between <sup>10</sup>Be records from Greenland and Antarctica over the last 100 years have led to different conclusions about past changes in solar activity. The reasons for this disagreement remain unresolved. We analyze a seasonally resolved <sup>10</sup>Be record from a firn core (North Greenland Eemian Ice Drilling [NEEM] ice core project) in Northwestern Greenland for 1887–2002. By comparing the NEEM data to <sup>10</sup>Be data from the NGRIP and Dye3 ice cores, we find that the Dye3 data after 1958 are significantly lower. These low values lead to a normalization problem in solar reconstructions when connecting <sup>10</sup>Be variations to modern observations. Excluding these data strongly reduces the differences between solar reconstructions over the last 2,000 years based on Greenland and Antarctic <sup>10</sup>Be data. Furthermore, <sup>10</sup>Be records from polar regions and group sunspot numbers do not support a substantial increase in solar activity for the 1937–1950 period as proposed by previous extensions of the neutron monitor data.</p>}},
  author       = {{Zheng, Minjie and Adolphi, Florian and Sjolte, Jesper and Aldahan, Ala and Possnert, Göran and Wu, Mousong and Chen, Peng and Muscheler, Raimund}},
  issn         = {{0094-8276}},
  keywords     = {{Dye3; ice core; NEEM; neutron monitor data; seasonally resolved Be; solar reconstructions}},
  language     = {{eng}},
  number       = {{4}},
  publisher    = {{American Geophysical Union (AGU)}},
  series       = {{Geophysical Research Letters}},
  title        = {{Solar Activity of the Past 100 Years Inferred From <sup>10</sup>Be in Ice Cores—Implications for Long-Term Solar Activity Reconstructions}},
  url          = {{http://dx.doi.org/10.1029/2020GL090896}},
  doi          = {{10.1029/2020GL090896}},
  volume       = {{48}},
  year         = {{2021}},
}