Configuration and Characteristics of Small-scale Magnetic Flux Ropes in the Solar Wind

Abstract:

We examine the small-scale magnetic flux rope structures in the solar wind by utilizing in-situ spacecraft data. In analogy to their large-scale counterparts, the small-scale flux ropes of durations about tens of minutes to a few hours when traversed by a spacecraft exhibit typical signatures, especially in magnetic field measurements, i.e., elevated magnetic field magnitude and significant rotation in field direction. The plasma parameters, however, may possess greater variability, in particular, not necessarily of low plasma beta value. Therefore the Grad-Shafranov reconstruction technique, which is non-force free in general, is applied to examine their configuration in two and a half dimensional geometry. We will examine several cases of such structures, occuring in the solar wind at different locations, namely, in the ambient solar wind, inside large-scale ICMEs, behind a travelling shock wave and near stream interface, or the Heliospheric Current Sheet (HCS). We will derive their topological configuration, and physical parameters characterizing these structures. Detailed comparison will be made to show possibly distinct features among these events. Implications related to their originations will also be discussed.