Fluctuations of atmospheric carbon-14 concentrations during the past century

1971 ◽  
Vol 321 (1544) ◽  
pp. 105-127 ◽  
Keyword(s):  
Solar Activity ◽  
Production Rate ◽  
Cosmic Ray ◽  
Solar Modulation ◽  
Past Century ◽  
Activity Maximum ◽  
Carbon 14 ◽  
The Past ◽  
Natural Carbon ◽  
Atmospheric Carbon

Variations in atmospheric carbon-14 concentrations during the past century have been studied through the analyses of wines, spirits and plant seeds. The results reveal that short-term fluctuations of carbon-14 concentrations have occurred which are negatively correlated with solar activity. Maximum correlation occurs with carbon-14 concentration minima preceding sunspot maxima by one year. The overall magnitude of the fluctuations, 3 % of the natural carbon-14 concentration, appears too large to be attributed to variations in the isotope production rate by solar modulation of the galactic cosmic ray flux. It is proposed that the fluctuations are the result of solar-sensitive mixing of stratospheric and tropospheric air masses through variations of the incident ultraviolet and corpuscular radiation over each solar cycle. Theoretical considerations require that stratospheric carbon-14 levels fluctuate in direct correlation with solar activity. These variations of natural carbon-14 activities in the troposphere represent a significant deviation from the basic assumption of the radiocarbon dating method and may introduce further uncertainty in the dating of ‘young’ materials. In addition, they endorse the universal use of the N. B. S. modern standard in carbon -14 assay. A long-term decrease in tropospheric carbon-14 concentrations was also observed and is attributed to a reduction in the mean production rate of carbon-14 through enhanced solar activity.

scholarly journals Solar Modulation Effects in Terrestrial Production of Carbon-14

Radiocarbon ◽  
1980 ◽  
Vol 22 (2) ◽  
pp. 133-158 ◽  
Author(s):  
Giuliana Castagnoli ◽  
Devendra Lal
Keyword(s):  
Solar Activity ◽  
Cosmic Ray ◽  
Solar Modulation ◽  
Carbon 14 ◽  
Cosmic Ray Modulation ◽  
The Earth ◽  
Secular Variations ◽  
Galactic Cosmic Ray ◽  
Long Term Variations

This paper is concerned with the expected deviations in the production rate of natural 14C on the earth due to changes in solar activity. We review the published estimates of the global production rates of 14C due to galactic and solar cosmic ray particles, and present new estimates of the expected secular variations in 14C production, taking into account the latest information available on galactic cosmic ray modulation and long-term variations in solar activity.

scholarly journals The Influence of Solar Activity and Cosmic Rays on Terrestrial Clouds and Global Warming

2001 ◽  
Vol 203 ◽  
pp. 602-605
Author(s):  
E. Pallé Bagó ◽  
C. J. Butler
Keyword(s):  
Solar Activity ◽  
Indirect Effects ◽  
Radiative Forcing ◽  
Cosmic Ray ◽  
Past Century ◽  
Direct And Indirect Effects ◽  
Cloud Data ◽  
The Past ◽  
Full Period ◽  
Cosmic Ray Flux

We analyse the new ISCCP (International Satellite Cloud Climatology Project) D2 cloud data to ascertain whether or not a connection between cosmic ray flux and cloud cover exists. Our results indicate that only the low-level cloud follows solar activity over the full period, 1983-1994. Using several proxies for solar activity and the radiative forcing for the ISCCP cloud types, we estimate the possible impact that such a solar-terrestrial connection may have on climate. We conclude that, possibly excluding the most recent decades, much of the warming of the past century can be quantitatively accounted for by the direct and indirect effects of solar activity.

scholarly journals Modeling of Atmospheric Radiocarbon Fluctuations for the Past Three Centuries

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 249-258 ◽  
Author(s):  
P E Damon ◽  
R S Sternberg ◽  
C J Radnell
Keyword(s):  
Magnetic Field ◽  
Fossil Fuels ◽  
Magnetic Field Intensity ◽  
Cosmic Ray ◽  
Solar Modulation ◽  
Geomagnetic Index ◽  
The Past ◽  
Dipole Magnetic Field ◽  
Climatic Time Series ◽  
Sunspot Record

Relatively precise quantitative observations of geophysical parameters are available to evaluate the fluctuations of atmospheric 14C activity during the past three centuries. As reviewed by Damon, Lerman, and Long (1978), these fluctuations seem to result from three factors: 1) changes in the earth's dipole magnetic field intensity, which has been decreasing since the first measurements by Gauss (McDonald and Gunst, 1968); 2) solar modulation of the cosmic-ray production, which has been correlated with the sunspot record of Waldmeier (1961), and more recently, to the Aa geomagnetic index by Stuiver and Quay (1980); and 3) the combustion of fossil fuels (Suess, 1955). A relationship between the climatic time series and the 14C-derived record of solar change has not yet been demonstrated (Stuiver, 1980).

scholarly journals Long-term solar activity explored with wavelet methods

2006 ◽  
Vol 24 (2) ◽  
pp. 769-778 ◽  
Author(s):  
H. Lundstedt ◽  
L. Liszka ◽  
R. Lundin ◽  
R. Muscheler
Keyword(s):  
Solar Activity ◽  
Production Rate ◽  
Sunspot Number ◽  
Maunder Minimum ◽  
High Solar Activity ◽  
Solar Modulation ◽  
Group Sunspot ◽  
Group Sunspot Number ◽  
Wavelet Methods

Abstract. Long-term solar activity has been studied with a set of wavelet methods. The following indicators of long-term solar activity were used; the group sunspot number, the sunspot number, and the 14C production rate. Scalograms showed the very long-term scales of 2300 years (Hallstat cycle), 900-1000 years, 400-500 years, and 200 years (de Vries cycle). Scalograms of a newly-constructed 14C production rate showed interesting solar modulation during the Maunder minimum. Multi-Resolution Analysis (MRA) revealed the modulation in detail, as well as peaks of solar activity not seen in the sunspot number. In both the group sunspot number scalogram and the 14C production rate scalogram, a process appeared, starting or ending in late 1700. This process has not been discussed before. Its solar origin is unclear. The group sunspot number ampligram and the sunspot number ampligram showed the Maunder and the Dalton minima, and the period of high solar activity, which already started about 1900 and then decreased again after mid 1990. The decrease starts earlier for weaker components. Also, weak semiperiodic activity was found. Time Scale Spectra (TSS) showed both deterministic and stochastic processes behind the variability of the long-term solar activity. TSS of the 14C production rate, group sunspot number and Mt. Wilson sunspot index and plage index were compared in an attempt to interpret the features and processes behind the long-term variability.

Evidence for Planetary Forcing of the Cosmic Ray Intensity and Solar Activity Throughout the Past 9400 Years

Solar Physics ◽  
2014 ◽  
Vol 289 (8) ◽  
pp. 3207-3229 ◽  
Author(s):  
K. G. McCracken ◽  
J. Beer ◽  
F. Steinhilber
Keyword(s):  
Solar Activity ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity ◽  
The Past

scholarly journals Patterns of Atmospheric 14C Changes

Radiocarbon ◽  
1980 ◽  
Vol 22 (2) ◽  
pp. 166-176 ◽  
Author(s):  
Minze Stuiver ◽  
Paul D Quay
Keyword(s):  
Solar Wind ◽  
Geomagnetic Field ◽  
Cosmic Ray ◽  
Solar Modulation ◽  
Production Rates ◽  
Climatic Fluctuation ◽  
The Past ◽  
Earth Magnetic Field ◽  
Carbon Reservoir ◽  
Cosmic Ray Flux

Natural atmospheric 14C changes are caused by fluctuations in upper atmospheric 14C production rates (Q) that are related to earth geomagnetic field variations and changes in solar wind magnetic shielding properties. Climate variability may also be responsible for some of the changes because it influences exchange rates of 14C between the various terrestrial carbon reservoirs.Upper atmospheric 14C production rates QM, in at/sec cm2 (earth), were calculated for the past 1200 years from the atmospheric 14C record and a carbon reservoir model. The changes in QM are compared in detail with the predicted Q variability derived from an Aa solar modulation mechanism and 20th century neutron flux observations. The influence of earth geomagnetic field changes on the magnitude of the solar wind modulation is discussed, and it is shown that the variations in this magnitude agree with the known differences in earth magnetic field intensity during the past 1200 years. The larger calculated QM oscillations during the sixth millennium bp also agree with this concept.Solar wind magnetic as well as geomagnetic forces modulate the incoming cosmic ray flux and explain the main features of the atmospheric 14C record. It is argued that climatic fluctuation is not a dominant cause.The oscillations between 3200 and 3700 BC, as measured by de Jong, Mook, and Becker, differ in rise time from those found for the current millennium.

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