Space plasma dynamics: Alfvén intermittent chaos

The onset of Alfvén intermittent chaos in space plasmas is studied by numerically solving the derivative non-linear Schrödinger equation (DNLS) under the assumption of stationary Alfvén waves. We describe how the Alfvénic fluctuations of the magnetic field can evolve from periodic to chaotic behavior through a sequence of bifurcations as the dissipation is varied. The collision of a chaotic attractor with an unstable periodic orbit leads to the generation of strongly chaotic behavior, in an event known as interior crisis. We also show that in the DNLS equation, chaotic attractors coexist with non-attracting chaotic sets responsible for transient chaotic behavior. After the interior crisis point, a wide chaotic attractor can be decomposed into two coupled non-attracting chaotic sets, resulting in intermittent chaotic time series.