Building a Small-scale Magnetic Flux Rope Database via the Grad-Shafranov Reconstruction Technique

The magnetic flux ropes in the solar wind are an important type of transient and coherent structures in the inner heliosphere. They constitute a special class of structures especially associated with slow solar wind, thus contributing to the variability of slow wind. A flux rope has the typical topology of winding magnetic field lines around a central axis. The small-scale flux ropes (of duration ranging from a few minutes to a few hours) have been intensively studied in recent years, since they alter the turbulent properties of the local medium, affect particle transport and energization, and are considered as the potential source of local acceleration. However, most of the current studies are based on the limited small-scale flux rope database, in which the cases were mostly identified by the minimum variance analysis and the constant-alpha, linear force-free, cylindrically symmetric field model fitting. In this study, we apply the Grad-Shafranov (GS) reconstruction technique to detect small-scale flux ropes and then build a database. The GS reconstruction technique is a tool to reconstruct the two and a half dimensional field structure based on in-situ measurements captured by an observing platform moving past it. It has the potential to detect more general flux rope structures and to generate more associated magnetic field and plasma parameters characterizing such structures. We present a preliminary list of the small-scale magnetic flux ropes identified and compare with previous established databases by other methods. The two and a half dimensional structure of some selected cases in the database will be reconstructed, and the summary results on flux rope properties will be discussed.