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Cosmic ray anomaly: The Saros cycle and a lunar perturbation
Author(s) -
Sonett Charles P.,
Smith Leonard A.
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl900322
Subject(s) - sidereal time , physics , cosmic ray , astrophysics , rotation period , perturbation (astronomy) , orbital period , astronomy , geology , stars
The power spectral density (frequency dependence of the variance) of the annual Stuiver radiocarbon record (Δ 14 C) contains a major line with a 17.5 ± 0.5 (2σ) year period which is proposed to result from a hitherto unexpected forcing of the cosmic ray (CR) flux at the top of the atmosphere. The only known natural period with a corresponding value is the synodic Saros cycle, the retrograde period of rotation of the Moon's nodal plane; 18.5 years is the sidereal nodal regression period. It is proposed that the intersection of the Moon's downstream diamagnetic solar wind cavity with the Earth at the Saros period is the source of the apparent cosmic ray anomaly leading to this periodic change of Δ 14 C; arguably, eclipsing and/or a low energy acceleration of the GCR could take place, though the evidence from the Fourier spectrum appears to favor acceleration.