Nonlinear Dynamics and Chaos in Space Plasmas

The theory and observation of nonlinear wave coupling phenomena in solar-system plasmas are reviewed. Rocket and satellite observations have provided evidence of nonlinear wave interactions in space plasmas, in particular, in relation to the generation and propagation of radio waves in solar corona, interplanetary medium and Earth's magnetosphere. These radio waves represent the electromagnetic signature of solar-terrestrial coupling and are useful for forecasting and monitoring of space weather. Nonlinear wave-wave coupling in plasmas can be modeled as a dynamical system of coupled oscillators involving one, two or higher-order wave triplets. For a three-wave dissipative system, the temporal transition from order to chaos may evolve via period doubling or intermittence. For a four-wave Hamiltonian system involving two coupled wave triplets, the spatiotemporal transition from order to chaos is analyzed using the concepts of stable and unstable homogeneous manifolds.