Recurring variations of probably solar origin in the atmospheric. Delta. sup 14 C time record

Journal Article · Sun Dec 31 23:00:00 EST 1989 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/GL017i001p00085· OSTI ID:5315341

Hood, L L; Jirikowic, J L ^[1]

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1. Univ. of Arizona (USA)

After removal of the {approximately}11,000-year geomagnetic contribution to a relatively high-precision atmospheric {Delta}{sup 14}C record covering the past 7,200 years, residual variations exhibit a 2,200-2,600 year quasi-periodicity that has been recognized in earlier studies. The authors find here that century-scale variations in the most recent cycle are positively correlated with similar short-term variations in each of the two previous cycles. Thus the quasi-periodicity consists of both a long-term variation of the mean and a superposed, approximately recurring pattern of century-scale variations. The strongest of these latter variations occur near successive maxima of the {approximately}2,400 year cycles. During the last millennium, the largest century-scale variations (occurring near the most recent 2,400 year maximum) are known to be mainly a consequence of the pronounced Maunder, Spoerer, and Wolf solar activity minima. Therefore, the recurrence of large amplitude {Delta}{sup 14}C variations at 2,400 year intervals is mot directly explained as due to solar forcing at both the {approximately}2,400 year and century-scale periods. A fully terrestrial 2,400 year modulation of an independent century-scale solar forcing function is disfavored by the joint occurrence of relatively strong {Delta}{sup 14}C maxima and solar activity minima during the current millennium, according to independent proxy records. The probable existence of a {approximately}2,400 year solar quasi-cycle has implications for the predictability of future pronounced solar activity minima and for the interpretation of certain minor Holocene climatic variations.

• OSTI ID: 5315341
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 17:1; ISSN GPRLA; ISSN 0094-8276
• Country of Publication: United States
• Language: English

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54 ENVIRONMENTAL SCIENCES
540110
58 GEOSCIENCES
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CARBON 14
CARBON ISOTOPES
CLIMATES
CORRELATIONS
ECOLOGICAL CONCENTRATION
ENERGY BUDGETS
EVEN-EVEN NUCLEI
GEOLOGIC HISTORY
ISOTOPES
LIGHT NUCLEI
NUCLEI
OSCILLATIONS
RADIATIONS
RADIOISOTOPES
SOLAR ACTIVITY
SOLAR RADIATION
STELLAR RADIATION
TIME DEPENDENCE
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YEARS LIVING RADIOISOTOPES