Testing for chaos in the solar wind and Alfvénic fluctuations Original Research Article

We analyse a time series of velocities of a low-speed stream of the solar wind plasma including Alfvénic fluctuations measured by the Helios spacecraft in the inner heliosphere. We use a nonlinear filter to give a faithful representation of nonlinear behaviour of the solar wind flow. The calculated Kolmogorov entropy and Lyapunov exponent are positive, which exhibit sensitivity to initial conditions.