Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record
Sunspot observations since 1610 A.D. show that the solar magnetic activity displays long-term changes, from Maunder Minimum-like low-activity states to Modern Maximum-like high-activity episodes, as well as short-term variations, such as the pronounced 11-year periodicity. Information on changes in...
Published in: | Solar Physics |
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2014
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Online Access: | https://pure.au.dk/portal/da/publications/reconstruction-of-subdecadal-changes-in-sunspot-numbers-based-on-the-ngrip-10be-record(81288ee0-d3f6-4dfc-8de3-717629959a6f).html https://doi.org/10.1007/s11207-014-0563-1 http://adsabs.harvard.edu/abs/2014SoPh.289.4377I |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/81288ee0-d3f6-4dfc-8de3-717629959a6f 2023-05-15T16:30:15+02:00 Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record Inceoglu, Fadil Knudsen, Mads Faurschou Karoff, Christoffer Olsen, Jesper 2014-11 https://pure.au.dk/portal/da/publications/reconstruction-of-subdecadal-changes-in-sunspot-numbers-based-on-the-ngrip-10be-record(81288ee0-d3f6-4dfc-8de3-717629959a6f).html https://doi.org/10.1007/s11207-014-0563-1 http://adsabs.harvard.edu/abs/2014SoPh.289.4377I eng eng info:eu-repo/semantics/restrictedAccess Inceoglu , F , Knudsen , M F , Karoff , C & Olsen , J 2014 , ' Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record ' , Solar Physics , vol. 289 , no. 11 , pp. 4377-4392 . https://doi.org/10.1007/s11207-014-0563-1 Sun: activity Sun: dynamo Solar-terrestrial relations Sunspots article 2014 ftuniaarhuspubl https://doi.org/10.1007/s11207-014-0563-1 2022-05-25T22:50:59Z Sunspot observations since 1610 A.D. show that the solar magnetic activity displays long-term changes, from Maunder Minimum-like low-activity states to Modern Maximum-like high-activity episodes, as well as short-term variations, such as the pronounced 11-year periodicity. Information on changes in solar activity levels before 1610 relies on proxy records of solar activity stored in natural archives, such as 10Be in ice cores and 14C in tree rings. These cosmogenic radionuclides are produced by the interaction between Galactic cosmic rays (GCRs) and atoms in the Earth's atmosphere; their production rates are anti-correlated with the solar magnetic activity. The GCR intensity displays a distinct 11-year periodicity due to solar modulation of the GCRs in the heliosphere, which is inversely proportional to, but out of phase with, the 11-year solar cycle. This implies a time lag between the actual solar cycles and the GCR intensity, which is known as the hysteresis effect. In this study, we use the North Greenland Ice Core Project (NGRIP) records of the 10Be flux to reconstruct the solar modulation strength (Φ), which describes the modulation of GCRs throughout the heliosphere, to reconstruct both long-term and subdecadal changes in sunspot numbers (SSNs). We compare three different approaches for reconstructing subdecadal-scale changes in SSNs, including a linear approach and two approaches based on the hysteresis effect, i.e. models with ellipse-linear and ellipse relationships between Φ and SSNs. We find that the ellipse approach provides an amplitude-sensitive reconstruction and the highest cross-correlation coefficients in comparison with the ellipse-linear and linear approaches. The long-term trend in the reconstructed SSNs is computed using a physics-based model and agrees well with the other group SSN reconstructions. The new empirical approach, combining a physics-based model with ellipse-modeling of the 11-year cycle, therefore provides a method for reconstructing SSNs during individual solar cycles based ... Article in Journal/Newspaper Greenland Greenland ice core Greenland Ice core Project ice core NGRIP North Greenland North Greenland Ice Core Project Aarhus University: Research Greenland Solar Physics 289 11 4377 4392 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Sun: activity Sun: dynamo Solar-terrestrial relations Sunspots |
spellingShingle |
Sun: activity Sun: dynamo Solar-terrestrial relations Sunspots Inceoglu, Fadil Knudsen, Mads Faurschou Karoff, Christoffer Olsen, Jesper Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record |
topic_facet |
Sun: activity Sun: dynamo Solar-terrestrial relations Sunspots |
description |
Sunspot observations since 1610 A.D. show that the solar magnetic activity displays long-term changes, from Maunder Minimum-like low-activity states to Modern Maximum-like high-activity episodes, as well as short-term variations, such as the pronounced 11-year periodicity. Information on changes in solar activity levels before 1610 relies on proxy records of solar activity stored in natural archives, such as 10Be in ice cores and 14C in tree rings. These cosmogenic radionuclides are produced by the interaction between Galactic cosmic rays (GCRs) and atoms in the Earth's atmosphere; their production rates are anti-correlated with the solar magnetic activity. The GCR intensity displays a distinct 11-year periodicity due to solar modulation of the GCRs in the heliosphere, which is inversely proportional to, but out of phase with, the 11-year solar cycle. This implies a time lag between the actual solar cycles and the GCR intensity, which is known as the hysteresis effect. In this study, we use the North Greenland Ice Core Project (NGRIP) records of the 10Be flux to reconstruct the solar modulation strength (Φ), which describes the modulation of GCRs throughout the heliosphere, to reconstruct both long-term and subdecadal changes in sunspot numbers (SSNs). We compare three different approaches for reconstructing subdecadal-scale changes in SSNs, including a linear approach and two approaches based on the hysteresis effect, i.e. models with ellipse-linear and ellipse relationships between Φ and SSNs. We find that the ellipse approach provides an amplitude-sensitive reconstruction and the highest cross-correlation coefficients in comparison with the ellipse-linear and linear approaches. The long-term trend in the reconstructed SSNs is computed using a physics-based model and agrees well with the other group SSN reconstructions. The new empirical approach, combining a physics-based model with ellipse-modeling of the 11-year cycle, therefore provides a method for reconstructing SSNs during individual solar cycles based ... |
format |
Article in Journal/Newspaper |
author |
Inceoglu, Fadil Knudsen, Mads Faurschou Karoff, Christoffer Olsen, Jesper |
author_facet |
Inceoglu, Fadil Knudsen, Mads Faurschou Karoff, Christoffer Olsen, Jesper |
author_sort |
Inceoglu, Fadil |
title |
Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record |
title_short |
Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record |
title_full |
Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record |
title_fullStr |
Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record |
title_full_unstemmed |
Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record |
title_sort |
reconstruction of subdecadal changes in sunspot numbers based on the ngrip 10 be record |
publishDate |
2014 |
url |
https://pure.au.dk/portal/da/publications/reconstruction-of-subdecadal-changes-in-sunspot-numbers-based-on-the-ngrip-10be-record(81288ee0-d3f6-4dfc-8de3-717629959a6f).html https://doi.org/10.1007/s11207-014-0563-1 http://adsabs.harvard.edu/abs/2014SoPh.289.4377I |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Greenland ice core Greenland Ice core Project ice core NGRIP North Greenland North Greenland Ice Core Project |
genre_facet |
Greenland Greenland ice core Greenland Ice core Project ice core NGRIP North Greenland North Greenland Ice Core Project |
op_source |
Inceoglu , F , Knudsen , M F , Karoff , C & Olsen , J 2014 , ' Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10 Be Record ' , Solar Physics , vol. 289 , no. 11 , pp. 4377-4392 . https://doi.org/10.1007/s11207-014-0563-1 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1007/s11207-014-0563-1 |
container_title |
Solar Physics |
container_volume |
289 |
container_issue |
11 |
container_start_page |
4377 |
op_container_end_page |
4392 |
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1766019973947326464 |