Oceanic El-Niño wave dynamics and climate networks

Abstract

The so-called El Niño-southern oscillation (ENSO) is the most important and influential climate phenomenon of contemporary climate variability, in which oceanic wave dynamics plays an important role. Here we develop and apply an approach based on network theory to quantify the characteristics of El-Niño related oceanic waves using the satellite dataset. Weassociate the majority of dominant long distance (≤500 km) links of the network with several kinds of oceanic waves, i.e. equatorial Kelvin, Ross by, and tropical instability waves. Notably, we find that the location of the outgoing (∼180°E) and in-coming hubs (∼140°W) of the climate network coincide with the locations of The wave initiation and dissipation, respectively. We also find that this dissipation at ∼140°Wismuch weaker during El-Niño times. Moreover, the hubs of the equatorial network agree with the locations of westerly wind burst activity and high wind vorticity, two mechanisms that were associated with Ross by waves activity. This novel quantification method that is directly based on observational data leads to a better understanding of the oceanic wave dynamics, and it can also improve our understanding of El-Niño dynamics or its prediction.