University of Oulu

Wu, C.-J.; Krivova, N. A.; Solanki, S. K.; Usoskin, I. G. (2018) Solar total and spectral irradiance reconstruction over the last 9000 years. A&A 620, A120,

Solar total and spectral irradiance reconstruction over the last 9000 years

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Author: Wu, C.-J.1,2; Krivova, N. A.1; Solanki, S. K.1,3;
Organizations: 1Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, Göttingen, Germany
2Georg-August-Universität Göttingen, Institute for Astrophysics, Göttingen, Germany
3School of Space Research, Kyung Hee University, Yongin, South Korea
4Space Climate Research Unit and Sodankylä Geophysical Observatory, University of Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.7 MB)
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Language: English
Published: EDP Sciences, 2018
Publish Date: 2019-10-04


Context: Changes in solar irradiance and in its spectral distribution are among the main natural drivers of the climate on Earth. However, irradiance measurements are only available for less than four decades, while assessment of solar influence on Earth requires much longer records.

Aims: The aim of this work is to provide the most up-to-date physics-based reconstruction of the solar total and spectral irradiance (TSI/SSI) over the last nine millennia.

Methods: The concentrations of the cosmogenic isotopes 14C and 10Be in natural archives have been converted to decadally averaged sunspot numbers through a chain of physics-based models. TSI and SSI are reconstructed with an updated SATIRE model. Reconstructions are carried out for each isotope record separately, as well as for their composite.

Results: We present the first ever SSI reconstruction over the last 9000 years from the individual 14C and 10Be records as well as from their newest composite. The reconstruction employs physics-based models to describe the involved processes at each step of the procedure.

Conclusions: Irradiance reconstructions based on two different cosmogenic isotope records, those of 14C and 10Be, agree well with each other in their long-term trends despite their different geochemical paths in the atmosphere of Earth. Over the last 9000 years, the reconstructed secular variability in TSI is of the order of 0.11%, or 1.5 W m−2. After the Maunder minimum, the reconstruction from the cosmogenic isotopes is consistent with that from the direct sunspot number observation. Furthermore, over the nineteenth century, the agreement of irradiance reconstructions using isotope records with the reconstruction from the sunspot number by Chatzistergos et al. (2017, A&A, 602, A69) is better than that with the reconstruction from the WDC-SILSO series (Clette et al. 2014, Space Sci. Rev., 186, 35), with a lower χ2-value.

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Series: Astronomy and astrophysics
ISSN: 0004-6361
ISSN-E: 1432-0746
ISSN-L: 0004-6361
Volume: 620
Article number: A120
DOI: 10.1051/0004-6361/201832956
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Funding: C.-J. Wu acknowledges support by the Max Planck Research School (IMPRS). I. U. acknowledges support by the Center of Excellence ReSoLVE (Academy of Finland Project No. 272157).
Academy of Finland Grant Number: 272157
Detailed Information: 272157 (Academy of Finland Funding decision)
Copyright information: © ESO 2018.