Interplanetary magnetic flux ropes and solar filaments

Abstract

This paper aims at clarifying the physical relationship between interplanetary magnetic clouds and solar magnetic fields. For this purpose, we analyzed twelve magnetic clouds whose magnetic field variations are well explained by a flux rope model. Attempts were made to determine the geometry of flux ropes that fit the observed magnetic field variations and to identify disappearances of solar filaments that can be associated with the generation of those magnetic structures. A comparison of the magnetic field structures of flux ropes fitted to the interplanetary observations and the structures of solar magnetic fields suggests a model for the generation of magnetic clouds, or interplanetary magnetic flux ropes. We propose that the solar magnetic field surrounding a disappearing filament already has a flux rope structure at the time of eruption and that the structure extends through interplanetary space to be observed as an interplanetary flux rope. In addition, a model is proposed for a possible three-dimensional structure of an interplanetary magnetic flux rope, and observational support is presented.