Characterization of Magnetic Flux Ropes in Space Plasmas

Magnetic flux ropes are a type of magnetic structures commonly occurring in space plasmas. They are observed in the Sun’s atmosphere, in the interplanetary space between Sun and Earth, and in near-Earth space (i.e., the magnetosphere). They possess distinct observational signatures in both magnetic field and plasma properties especially from the in-situ spacecraft measurements when they are sampled by one or more probes in space. They have been examined quantitatively by applying the unique data analysis methods to the in-situ spacecraft data. These methods are based on basic plasma physics theory describing equilibrium states under two-dimensional (2D) and three-dimensional (3D) geometries. In particular we describe the method for deriving a 2D cross section of a flux rope structure by solving the Grad-Shafranov (GS) equation, and illustrate its outputs in terms of the physical parameters characterizing the flux rope structures. We also present an additional model for a quasi-3D magnetic field configuration based on a basic theory for a linear force-free state in plasma science.