Determination of the eddy turn‐over time in the solar wind

The observations of magnetic field fluctuations and suprathermal ion spectra upstream of interplanetary shocks driven by coronal mass ejections (CMEs) give information on two time scales: (1) the eddy turn‐over time scale i.e. the non‐linear cascading time scale of solar wind turbulence, and (2) the growth time scale for waves amplified by energetic protons accelerated at the shock. These two time scales scale differently with wave number. From an analysis of data from the ACE magnetometer and the suprathermal particle sensor SOHO/STOF we derive the solar‐wind eddy turn‐over time.