ABSTRACT
The solar wind is a complex phenomenon whose detailed behavior reflects the consequences of fluid behavior, kinetic processes, and solar activity. As sunspots wax and wane over the 22-year solar cycle, many properties of the solar wind vary in tandem with the sunspots. During solar minimum in fast flows the magnetofluid turbulence in the solar wind is often highly Alfvenic, that is, the fluctuations in velocity and magnetic field are correlated in fast wind. The slow solar wind is denser and more variable than fast wind and its composition reflects that of the solar corona in contrast with the composition of fast wind which more closely resembles that of the photosphere. One characteristic of magnetic clouds is that, unlike normal solar wind, the magnetic energy density of magnetic clouds exceeds the energy density of the solar wind flow. The geoeffectiveness of interplanetary coronal mass ejections and magnetic clouds varies from event to event and from solar cycle to solar cycle.
