Странный нехаотический аттрактор

Processes of the El Ni  ̃no – Southern Oscillation (ENSO) are investigated based on the mathematical theory of the so-called the strange nonchaotic attractor (SNA) in the quasiperiodically forced dynamic systems, and using the sea surface temperature and the atmospheric sea-level pressure data for the 1870–2014 year period.

The physical realizable system of ring structure, with a fixed irrational ratio of basic frequencies of external driving (the golden mean) manifests a strange nonchaotic attractor (SNA), similar to the attractor in the abstract map on a torus proposed and analyzed earlier by Hunt and Ott as an example of robust SNA.

Dynamics and space of сontrol parameters for a nonlinear oscillator under quasi­periodic driving are investigated experimentally by using a nonlinear circuit with p­n junction diode and numerically by using maps and differential equations. The dynamics of the systems under quasiperiodic driving is invariant due to initial driving phases, as a result the plane of the driving amplitudes is symmetrical.