Fig. 2: Synchronization of CP and South Atlantic decadal SSTs.
From: Synchronous decadal climate variability in the tropical Central Pacific and tropical South Atlantic
Heterogeneous correlation patterns (shading) for the leading pair of the MCA mode between a the tropical Pacific (120° E–80° W, 30° S–30° N) and b the Atlantic (70° W–20° E, 55° S–35° N) 8–16-year bandpass filtered MAMJJA SST anomalies. The cyan contours denote isolines of ±0.73 and 0.81, corresponding to the 90% and 95% confidence levels with approximately 6 decadal cycles. c Normalized principal components (PCs) for the Pacific (red) and Atlantic (blue) MCA SST modes. The normalized decadal Niño4 (purple; 160° E–150° W, 5° S–5° N) and sign-reversed tropical South Atlantic (ATLS; orange; 40° W–10° E, 15° S–0° N) SST indices are also superimposed, with areas enclosed by black dashed boxes in (a, b). Multi-taper (tapers = 3) power spectra of the MAMJJA raw d Niño4, e sign-reversed ATLS SST index, and f their coherence spectrum. The 90% and 95% confidence levels based on an AR(1) null hypothesis are shown as red dashed lines, while the orange shading denotes the quasi-decadal timescale of 8–16 years. g Cross-correlation coefficients as a function of the year between the pair MCA PCs (black line) and SST indices (red line). Positive leads indicate that the Pacific signal leads the Atlantic signal and vice versa. Large and small filled dots mark correlations above the 90% and 95% confidence levels.
