Hostname: page-component-745bb68f8f-kw2vx Total loading time: 0 Render date: 2025-01-08T00:39:39.427Z Has data issue: false hasContentIssue false
  • English
  • Français

Patterns of Atmospheric 14C Changes

Published online by Cambridge University Press:  18 July 2016

Minze Stuiver  and
Paul D Quay
Minze Stuiver
Affiliation:
Department of Geological Sciences, Quaternary Research Center, University of Washington, Seattle, Washington 98195
Paul D Quay
Affiliation:
Department of Geological Sciences, Quaternary Research Center, University of Washington, Seattle, Washington 98195
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

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.

Type
Natural 14C Variations
Information
Radiocarbon , Volume 22 , Issue 2 , 1980 , pp. 166 - 176
Copyright
Copyright © The American Journal of Science 

References

Barton, C E, Merrill, R T, and Barbetti, Michael, in press, Intensity of the earth's magnetic field during the past 10,000 years: Phys Earth Planetary Interiors, in press.Google Scholar
Eddy, J A, 1976, The Maunder Minimum: Science, v 192, p 1189–1202.Google Scholar
Houtermans, J C, 1971, Geophysical interpretations of the Bristlecone radiocarbon measurements using the method of Fourier analysis of unequally spaced data: Doctoral dissert, Univ Bern.Google Scholar
de Jong, A F M, Mook, W G, and Becker, Bernd, 1979, Confirmation of the Suess wiggles: 3200-3700 BC: Nature, v 280, p 48–49.Google Scholar
Lingenfelter, R E, and Ramaty, R, 1970, Astrophysical and geophysical variations in 14C production, in Olsson, I U, ed, Radiocarbon variations and absolute chronology, Nobel symposium, 12th, Proc: New York, John Wiley & Sons, p 513–537.Google Scholar
Mayaud, P N, 1972, The Aa indices: A 100 year series characterizing the magnetic activity: Jour Geophys Research, v 77, p 6870–6874.Google Scholar
Oeschger, Hans, Siegenthaler, U, Schotterer, U, and Gugelmann, A, 1975, A box diffusion model to study the carbon dioxide exchange in nature: Tellus, v 27, p 168–192.Google Scholar
Stuiver, Minze and Quay, P D, 1980, Changes in atmospheric 14C attributed to a variable sun: Science, v 207, p 11–19.Google Scholar
Waldmeyer, M, 1961, The sunspot activity in the years 1610-1960: Zürich, Pub Schulthess.Google Scholar