The thermoluminescence profile of a recent sea sediment core and the solar variability

Abstract

The analysis of the thermoluminescence (TL) profile of the GT14 recent sea sedimentary core shows the existence of four main periodicities of 137.7, 59,12.06, and 10.8 years. Here we discuss the affinity of these waves to the known cycles of solar variability. The beats of the two high frequency components produce a modulated wavetrain with a carrier wave of 11.4 years and an amplitude modulation with period 206 years. The minima of this squared amplitude modulation fall in 1810 and 1913 A.D. and closely correspond to the periods of lowest solar activity as indicated by the sunspot series. The sum of the two low frequency waves can in turn be rewritten as a component with period 82.6 years which is amplitude modulated by a second component with period of 206 years. The 82.6-yr wave has the period commonly attributed to the Gleissberg cycle of solar activity. The maxima of the 82.6-yr wave occur in agreement with the dates of maximum solar radius as suggested by Gilliland (1981).