CHAOS AND TURBULENCE IN SOLAR-WIND

Large amplitude waves as well as turbulence has been observed in the i nterplanetary medium. This turbulence is not understood to the extent that one would like to. By means of techniques of nonlinear dynamical systems, attempts are being made to properly understand the turbulence in the solar wind, which is essentially a nonuniform streaming plasma consisting of hydrogen and a fraction of helium. We demonstrate that the observed large amplitude waves can generate solitary waves, which in turn, because of some propagating solar disturbance, can produce ch aos in the medium. The chaotic fields thus generated can lead to anoma lously large plasma heating and acceleration. Unlike the solitary wave s in uniform plasmas, in nonuniform plasmas we get accelerated solitar y waves, which lead to electromagnetic as well as electrostatic (e.g. ion acoustic) radiations. The latter can be a very efficient source of plasma heating.