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 3 Main descriptive parameters and Fourier frequency results of the δ¹⁸O subcomponents isolated from the detrended component-1 and component-2 by singular spectrum analysis. The processing of the subcomponents was conducted to better separate and estimate the variance fraction of specific frequency bands from still complex data components. The italicized percentage values are the absolute variance of the subcomponents (referred to the total LR04 variance)

δ¹⁸O comp. rank	δ¹⁸O comp. variance (%)	δ¹⁸O subcomp. rank and var. (abs.)		δ¹⁸O subcomp. var. (rel.) (%)	δ¹⁸O subcomp. var. (abs) (%)	Frequency (kyr⁻¹)	TISA power (%)	Period (kyr)	Forcing
1	81.5	exp.fit		93.8	76.4	–	–	–	Long-term trend
		detrend 6.2% (5.1%)	1	44.2	2.25	0.0002668	95.8	3748	Earth’s orbit secular frequency
			1	44.2	2.25	0.0011701	4.2	855	Eccentricity (long)
			2	11.9	0.61	0.0024443	80.6	409	Eccentricity (long)
			2	11.9	0.61	0.0034017	19.4	294	Earth’s orbit secular frequency
			3–11	43.8	2.23	0.0034062	15.2	294	Earth’s orbit secular frequency
						0.0051199	24.9	195	Obliquity modulation cycle
						0.0061180	17.2	163	Obliquity modulation cycle
						0.0075215	15.9	133	Eccentricity (short)
						0.0093867	12.7	107
						0.0105655	14.1	95
2	7.3	1–4, 9–15		75.3	5.5	0.0105637	56.6	95	Eccentricity (short)
		1–4, 9–15		75.3	5.5	0.0140872	43.4	71	Eccentricity (short)
		5–8		24.4	1.8	0.0244321	67.5	41	Obliquity
		5–8		24.4	1.8	0.0186582	32.5	54	Obliquity