Nonlinear characterization and interaction in teleconnection patterns

The complexity in atmospheric parameters not only place a limit on their predictability but also influence their mutual interaction. Our goal in this research is to investigate (i) the nonlinear characteristics, and (ii) nonlinear interaction patterns amongst twelve teleconnection indices including Atlantic Multidecadal Oscillation (AMO), North Atlantic Oscillation (NAO), Pacific North Atlantic American Index (PNA), Quasi-biennal Oscillation (QBO), Arctic Oscillation (AO), and Western Pacific Index (WP), using tools from chaos theory. Monthly data for the indices between January 1948 and December 2016 were obtained and analyzed in this study. AMO and QBO showed the least chaotic behaviour with 0-1 test values of 0 and 0.5458. High significant correlations greater than 0.9 were observed between PNA-NAO and WP-PNA pairs. High values of recurrence rate, determinism, laminarity and Lmax suggests that AMO and QBO are periodic and stochastic signals respectively. Nonlinear interactions between pairs of teleconnection indices were investigated using interdependence measure, mutual information and cross correlation analysis. Strongest interactions were found in the PNA-NAO, WP-NAO, AO-NAO, AO-PNA, WP-AO, and WP-PNA pair of teleconnection indices.