Estimates of Mutual Influences between Sea Surface Temperature Variations in Tropical Pacific, Atlantic, and Indian Oceans from Long-Period Data Series
Based on the concept of the Wiener - Granger causality, we have performed seasonal trivariate analysis of directional couplings between sea surface temperature variations in tropical Pacific, Atlantic, and Indian oceans. These variations are related to significant modes of regional and global climatic variability. We have analyzed time series of monthly indices of Pacific Ocean processes El-Nino/Southern Oscillation (ENSO), equatorial Atlantic mode (EAM), and Indian Ocean Dipole (IOD) along with its western and eastern poles for the period of 1870-2015. We have developed a scheme of interactions between the processes under study where coupling strength estimates are presented along with estimates of the season of its maximal value and the coupling coefficient sign. As the most significant couplings we have found seasonal influences of ENSO on the western and eastern poles of IOD, the eastern pole of IOD on ENSO, EAM on ENSO, and IOD on EAM.