Single-spacecraft Identification of Flux Tubes and Current Sheets in the Solar Wind

A novel technique is presented for describing and visualizing the local topology of the magnetic field using single-spacecraft data in the solar wind. The approach merges two established techniques: the Grad-Shafranov (GS) reconstruction method, which provides a plausible regional two-dimensional magnetic field surrounding the spacecraft trajectory, and the Partial Variance of Increments (PVI) technique that identifies coherent magnetic structures, such as current sheets. When applied to one month of Wind magnetic field data at 1 minute resolution, we find that the quasi-two-dimensional turbulence emerges as a sea of magnetic islands and current sheets. Statistical analysis confirms that current sheets associated with high values of PVI are mostly located between and within the GS magnetic islands, corresponding to X points and internal boundaries. The method shows great promise for visualizing and analyzing single-spacecraft data from missions such as Parker Solar Probe and Solar Orbiter, as well as 1 au Space Weather monitors such as ACE, Wind, and IMAP.