Fig. 3. Power spectral analysis of Saharan dust and carbonate records.

Power spectral analyses (top) and associated coherences (bottom) conducted with the AnalySeries software (46). (A) ODP659 and MD03-2705 dust percentages, (B) MD03-2705 ²³⁰Th-normalized dust fluxes, and (C) MD03-2705 ²³⁰Th-normalized carbonate fluxes for the past 240 ka. Dashed line represents ODP659 data, and black line represents MD03-2705 data. Gray bars highlight the main orbital cyclicities (100, 41, and 23 ka) for which a peak in power variance is associated with a coherence higher than 0.5. While the length of the studied period (240 ka) is too short to make firm conclusions about 100-ka cyclicity, the changes in 41- and 23-ka variabilities are robust.