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Titel |
The ~ 2400-year cycle in atmospheric radiocarbon concentration: bispectrum of 14C data over the last 8000 years |
VerfasserIn |
S. S. Vasiliev, V. A. Dergachev |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 20, no. 1 ; Nr. 20, no. 1, S.115-120 |
Datensatznummer |
250014347
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Publikation (Nr.) |
copernicus.org/angeo-20-115-2002.pdf |
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Zusammenfassung |
We have carried out power
spectrum, time-spectrum and bispectrum analyses of the long-term series of the
radiocarbon concentrations deduced from measurements of the radiocarbon content
in tree rings for the last 8000 years. Classical harmonic analysis of this time
series shows a number of periods: 2400, 940, 710, 570, 500, 420, 360, 230, 210
and 190 years. A principle feature of the time series is the long period of ~
2400 years, which is well known. The lines with periods of 710, 420 and 210
years are found to be the primary secular components of power spectrum. The
complicated structure of the observed power spectrum is the result of ~
2400-year modulation of primary secular components. The modulation induces the
appearance of two side lines for every primary one, namely lines with periods
of 940 and 570 years, of 500 and 360 years, and 230 and 190 years. The
bispectral analysis shows that the parameters of carbon exchange system varied
with the ~ 2400-year period during the last 8000 years. Variations of these
parameters appear to be a climate effect on the rate of transfer of 14C
between the atmosphere and the the ocean.
Key words. Meteorology and
atmospheric dynamics (climatology; ocean-atmosphere interaction;
paleoclimatology) |
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