Re-analysis of Lepping's Fitting Method for Magnetic Clouds: Lundquist Fit Reloaded

This cartoon neatly explains how the twist of a flux rope (FR here) must be distributed following magnetic reconnection, either in a flare/CME context or out in the solar wind. It shows a top view of the reconnection process, with the purple arcs representing the flare loops left behind as the FR rises (for a perspective view, also in full color, see Gosling). The analysis compares the "Lundquist" and Gold-Hoyle models of the poloidal field (or current density j) across these different mathematical representations, in the context of standard fitting. The cartoon compares the twist of the resultant FR near its core and at its periphery. The Archivist notes that this laudable work, like so many in this genre, omits any discussion of the seemingly crucial physics of matching the twist in the corona to the twist represented by ∇ x B in the photospheric boundary.