A Phenomenological Study of the Cosmic Ray Variations over the Past 9400 Years, and Their Implications Regarding Solar Activity and the Solar Dynamo
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Two 9400-year long 10Be data records from the Arctic and Antarctic and a 14C record of equal length were used to investigate the periodicities in the cosmic radiation incident on Earth throughout the past 9400 years. Fifteen significant periodicities between 40 and 2320 years are observed in the 10Be and 14C records, there being close agreement between the periodicities in each record. We found that the periodic variations in the galactic cosmic radiation are the primary cause for periods < 250 years, with minor contributions of terrestrial origin possible > 250 years. The spectral line for the Gleissberg (87-year) periodicity is narrow, indicating a stability of ≈ 0.5 %. The 9400-year record contains 26 Grand Minima (GM) similar to the Maunder Minimum, most of which occurred as sequences of 2 – 7 GM with intervals of 800 – 1200 years in between, in which there were no GM. The intervals between the GM sequences are characterised by high values of the modulation function. Periodicities < 150 years are observed in both the GM intervals and the intervals in between. The longer-period variations such as the de Vries (208-year) cycle have high amplitudes during the GM sequences and are undetectable in between. There are three harmonically related pairs of periodicities (65 and 130 years), (75 and 150 years), and (104 and 208 years). The long periodicities at 350, 510, and 708 years closely approximate 4, 6, and 8 times the Gleissberg period (87 years). The well-established properties of cosmic-ray modulation theory and the known dependence of the heliospheric magnetic field on the solar magnetic fields lead us to speculate that the periodicities evident in the paleo-cosmic-ray record are also present in the solar magnetic fields and in the solar dynamo. The stable, narrow natures of the Gleissberg and other periodicities suggest that there is a strong “frequency control” in the solar dynamo, in strong contrast to the variable nature (8 – 15 years) of the Schwabe (11-year) solar cycle.
KeywordsCosmic-rays Cosmic-ray modulation Cosmogenic 10Be and 14C Solar periodicities Grand Minima Solar dynamo
The research at the University of Maryland was supported by NSF grant 1050002. The Swiss component of this research was supported by NCCR Climate – Swiss climate research and by the Swiss National Science Foundation under grant CRSI122-130642 (FUPSOL). Support of KGMcC by the International Space Science Institute (ISSI) is gratefully acknowledged.
- Abreu, J.A., Beer, J., Steinhilber, F., Christl, M., Kubik, P.W.: 2012a, 10Be in ice cores and 14C in tree rings: separation of production and climate effects. Space Sci. Rev. 1 – 7. doi: 10.1007/s11214-011-9864-y.
- Charbonneau, P.: 2010, Dynamo models of the solar cycle. Living Rev. Solar Phys. 7(3). http://www.livingreviews.org/lrsp-2010-3.
- Gleissberg, W.: 1958, The eighty-year sunspot cycle. J. Br. Astron. Assoc. 68, 148 – 152. Google Scholar
- Gleissberg, W.: 1965, The eighty-year solar cycle in auroral frequency numbers. J. Br. Astron. Assoc. 75, 227 – 231. Google Scholar
- Jokipii, J.R.: 1991, Variations of the cosmic-ray flux with time. In: Sonett, C.P., Giampapa, H.S., Mathews, M.S. (eds.) The Sun in Time, Univ. Ariz. Press, Tucson, 205 – 220. Google Scholar
- McCracken, K., Beer, J., Steinhilber, F.: 2013, Evidence for planetary forcing of the cosmic ray intensity, and solar activity throughout the past 9400 years. Solar Phys. submitted Google Scholar
- Reimer, P.J., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Blackwell, P.G., Ramsey, C.B., Buck, C.E., Burr, G.S., Edwards, R.L., Friedrich, M., Grootes, P.M., Guilderson, T.P., Hajdas, I., Heaton, T.J., Hogg, A.G., Hughen, K.A., Kaiser, K.F., Kromer, B., McCormac, F.G., Manning, S.W., Reimer, R.W., Richards, D.A., Southon, J.R., Talamo, S., Turney, C.S.M., van der Plicht, J., Weyhenmeye, C.E.: 2009, Intcal09 and Marine09 radiocarbon age calibration curves, 0 – 50 000 years Cal Bp. Radiocarbon 51, 1111 – 1150. Google Scholar
- Steinhilber, F., Abreu, J.A., Beer, J., Brunner, I., Christl, M., Fischer, H., Heikkilä, U., Kubik, P.W., Mann, M., McCracken, K.G., Miller, H., Miyahara, H., Oerter, H., Wilhelms, H.: 2012, 9400 years of cosmic radiation and solar activity from ice cores and tree rings. Proc. Natl. Acad. Sci. USA 109. doi: 10.1073/pnas1118965109.
- Webber, W.R., Higbie, P.R.: 2010, A comparison of new calculations of 10Be production in the Earth’s polar atmosphere by cosmic-rays with 10Be concentration measurements in polar ice cores between 1939 and 2005 – A troubling lack of concordance, paper 1. arXiv:1003.4989.
- Webber, W.R., Higbie, P.R., Webber, C.W.: 2010, A comparison of new calculations of the yearly 10Be production in the Earth’s polar atmosphere by cosmic rays with yearly 10Be measurements in multiple Greenland ice cores between 1939 and 1994 – A troubling lack of concordance, paper 2. arXiv:1004.2675.