Sack Lunch Seminar (SLS)

El Ninõ–Southern Oscillation is here considered as large (time) scale phenomenon emerging from a complex and fast general dynamical system.

This seminar has two main goals. The first one is to give a physically reasonable explanation for the use of stochastic models for mimicking the apparent random features of the El Ninõ–Southern Oscillation (ENSO) phenomenon. The second one is to show how it is possible to obtain, with the present approach, some analytical results concerning the stationary density function of the anomaly sea surface temperature, and the occurring timing of strong El Ninõ events.
These results fit well the data from observations, reproducing the asymmetry and the power law tail of the histograms of the NIÑO3 index and the timing of 2-7 years for intermediate El Ninõ events.
The approach is based on some of our recent theoretical results in the field of the dynamical origin of stochastic processes. More precisely, we apply this approach to the celebrated recharge oscillator model (ROM), weakly interacting by a multiplicative term with a general deterministic system (Madden-Julian Oscillations, westerly wind burst, etc.), and we obtain a Fokker-Planck Equation that describes the statistical behavior of the ROM.

For more details
— M. Bianucci, Geophysical Res. Lett., 43(1), 386-394 http://dx.doi.org/10.1002/2015GL066772
— M. Bianucci, Journal of Statistical Mechanics: Theory and Experiment 2015, P05016 (2015), http://stacks.iop.org/1742-5468/2015/i=5/a=P05016;
— M. Bianucci, Int. Journal of Mod. Phys. B 0, 1541004 (2015), http://www.worldscientific.com/doi/abs/10.1142/S0217979215410040