Mirror mode structures in the solar wind at 0.72 AU

Abstract

Magnetic holes in the solar wind with little or no directional change across the magnetic depression are related to mirror mode structures. Recently, Zhang et al. (2008) determined the characteristic size and shape of such mirror mode structures in the solar wind at 0.72 AU. They found that the mirror mode structure in the solar wind is quite elongated along the field direction. In this report, we examine the size and shape of isolated magnetic holes and train of holes, separately. We find that the isolated holes are slightly smaller in width and more elongated than the multiple holes. This observation suggests a particular evolutionary history of mirror mode structures in the solar wind in which multiple holes coalesce with time into isolated structures more elongated parallel to the magnetic field.