δ18O and SST signal decomposition and dynamic of the Pliocene-Pleistocene climate system: new insights on orbital nonlinear behavior vs. long-term trend

Progress in Earth and Planetary Science

Table 9 Cross-spectral analysis results between orbitally driven δ¹⁸O and SST components for the last 5 Myr. Data standardized (mean = 0, standard deviation = 1) and, where necessary, inverted to have the same paleoclimatic polarity (positive values for positive forcing and warming)

SST component	δ¹⁸O component	Cross-spectrum freq. (kyr⁻¹)	Cross-spectrum period (kyr)	Coherency	Phase shift
SST comp-2 subcomp-1-4	LR04 comp-2 subcomp-1-4, 9-15	0.010498	95	0.89	0.20°	0.05 kyr	δ¹⁸O leads SST eccentricity comp.
SST comp-2 subcomp-1-4 (post-ONHG)	LR04 comp-2 subcomp-1-4, 9-15 (post-ONHG)	0.010498	95	0.84	− 0.38°	− 0.10 kyr	δ¹⁸O lags SST eccentricity comp.
SST comp-3-4	LR04 comp-3-4	0.024414	41	0.92	− 24.57°	− 2.80 kyr	δ¹⁸O lags SST obliquity comp.
SST comp-5-7	LR04 comp-5-7	0.044800	22	0.46	− 16.40°	− 1.02 kyr	δ¹⁸O lags SST precession comp.