noaa-forcing-18475 Solar Variability Over the Last 3000 Years Usoskin, I.G.; Hulot, G.; Gallet, Y.; Roth, R.; Licht, A.; Joos, F.; Kovaltsov, G.A.; Thébault, E.; Khokhlov, A. Solar Variability Over the Last 3000 Years 2015-04-26 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/18475 Investigator I.G. Usoskin Investigator G. Hulot Investigator Y. Gallet Investigator R. Roth Investigator A. Licht Investigator F. Joos Investigator G.A. Kovaltsov Investigator E. Thébault Investigator A. Khokhlov earth science paleoclimate climate forcing solar modulation potential,null,95% confidence interval upper bound,megavolt,null,climate forcing,null,null,N,null earth science paleoclimate climate forcing sunspot number,null,95% confidence interval lower bound,count,null,climate forcing,null,null,N,null earth science paleoclimate climate forcing sunspot number,null,95% confidence interval upper bound,count,null,climate forcing,null,null,N,null earth science paleoclimate climate forcing age,null,null,year Common Era,null,climate forcing,null,null,N,null earth science paleoclimate climate forcing solar modulation potential,null,95% confidence interval lower bound,megavolt,null,climate forcing,null,null,N,null earth science paleoclimate climate forcing solar modulation potential,null,null,megavolt,null,climate forcing,null,null,N,null earth science paleoclimate climate forcing sunspot number,null,null,count,null,climate forcing,null,null,N,null earth science paleoclimate climate forcing solar geoscientificInformation -1145 AD 1945 AD 3095 cal yr BP 5 cal yr BP Complete -90 90 -180 180 Geographic Region Global Global>LATITUDE >LONGITUDE None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Usoskin, I.G; Hulot, G; Gallet, Y.; Roth, R.; Licht, A.; Joos, F.; Kovaltsov, G.A.; Thébault, E.; Khokhlov, A. 2014 Astronomy and Astrophysics L10 562 10.1051/0004-6361/201423391 http://www.aanda.org/articles/aa/abs/2014/02/aa23391-14/aa23391-14.html

Aims. The Sun shows strong variability in its magnetic activity, from Grand minima to Grand maxima, but the nature of the variability is not fully understood, mostly because of the insufficient length of the directly observed solar activity records and of uncertainties related to long-term reconstructions. Here we present a new adjustment-free reconstruction of solar activity over three millennia and study its different modes. Methods. We present a new adjustment-free, physical reconstruction of solar activity over the past three millennia, using the latest verified carbon cycle, 14C production, and archeomagnetic field models. This great improvement allowed us to study different modes of solar activity at an unprecedented level of details. Results. The distribution of solar activity is clearly bi-modal, implying the existence of distinct modes of activity. The main regular activity mode corresponds to moderate activity that varies in a relatively narrow band between sunspot numbers 20 and 67. The existence of a separate Grand minimum mode with reduced solar activity, which cannot be explained by random fluctuations of the regular mode, is confirmed at a high confidence level. The possible existence of a separate Grand maximum mode is also suggested, but the statistics is too low to reach a confident conclusion. Conclusions. The Sun is shown to operate in distinct modes - a main general mode, a Grand minimum mode corresponding to an inactive Sun, and a possible Grand maximum mode corresponding to an unusually active Sun. These results provide important constraints for both dynamo models of Sun-like stars and investigations of possible solar influence on Earth's climate. STUDY NOTES: Solar variability, reconstructed from 14C data (Roth and Joos, 2013) using new archeomagnetic data (Licht et al., 2013)

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/solar_variability/usoskin2014solar.txt Data File; 3,000 Year Solar Variability Reconstruction USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11