Oceanic El-Nino wave dynamics and climate networks

The so-called El Nino-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-Nino related oceanic waves using the satellite dataset. We associate the majority of dominant long distance (>= 500 km) links of the network with several kinds of oceanic waves, i.e. equatorial Kelvin, Rossby, and tropical instability waves. Notably, we find that the location of the outgoing (similar to 180 degrees E) and in-coming hubs (similar to 140 degrees W) of the climate network coincide with the locations of the wave initiation and dissipation, respectively. We also find that this dissipation at similar to 140 degrees W is much weaker during El-Nino 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 Rossby 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-Nino dynamics or its prediction.