(a) Nino3.4 SSTA wavelet power spectrum (1950–2050)
(b) Spectrum of SSTA in Nino3.4 region
Figure 6: The evolution of the difference of the sea level pressure anomaly (ΔSLP) between East Pacific (80°E-160°E, 5°S-5°N) and West Pacific (160°W-80°W, 5°S-5°N) and zonal wind stress anomaly in equatorial Pacific (120°E-70°W, 5°S-5°N) since the 20th century from IPCC-AR4IPCC-AR4 data.