Abstract
Abstract. We present the first results of a data analysis method, developed by Sonnerup and Hasegawa (2011), for reconstructing three-dimensional (3-D), magnetohydrostatic structures from data taken as two closely spaced satellites traverse the structures. The method is applied to a magnetic flux transfer event (FTE), which was encountered on 27 June 2007 by at least three (TH-C, TH-D, and TH-E) of the five THEMIS probes near the subsolar magnetopause. The FTE was sandwiched between two oppositely directed reconnection jets under a southward interplanetary magnetic field condition, consistent with its generation by multiple X-line reconnection. The recovered 3-D field indicates that a magnetic flux rope with a diameter of ~ 3000 km was embedded in the magnetopause. The FTE flux rope had a significant 3-D structure, because the 3-D field reconstructed from the data from TH-C and TH-D (separated by ~ 390 km) better predicts magnetic field variations actually measured along the TH-E path than does the 2-D Grad–Shafranov reconstruction using the data from TH-C (which was closer to TH-E than TH-D and was at ~ 1250 km from TH-E). Such a 3-D nature suggests that the field lines reconnected at the two X-lines on both sides of the flux rope are entangled in a complicated way through their interaction with each other. The generation process of the observed 3-D flux rope is discussed on the basis of the reconstruction results and the pitch-angle distribution of electrons observed in and around the FTE.
Highlights
Magnetic field structures and topologies play an important role in dynamical plasma phenomena, such as solar or stellar flares (e.g. Kusano et al, 2012; Bamba et al, 2013) and magnetospheric substorms (e.g. Consolini and Chang, 2001), and in the transfer of mass, momentum, and energy in space and astrophysical plasmas
A key physical process underlying the rearrangement of field line configurations and topology changes is magnetic reconnection, which is known to occur in the solar corona (e.g. Masuda et al, 1994), solar wind (e.g. Gosling et al, 2005), and magnetotail (e.g. Nagai et al, 2013), and at the magnetopause (e.g. Sonnerup et al, 1981)
These two quantities should be preserved along the field lines in 2-D GS equilibria (e.g. Sonnerup et al, 2006), and this property has been used in the method, developed by Hu and Sonnerup (2002), for estimating the axial (Z) orientation of magnetic flux ropes on the basis of single-spacecraft measurements
Summary
Magnetic field structures and topologies play an important role in dynamical plasma phenomena, such as solar or stellar flares (e.g. Kusano et al, 2012; Bamba et al, 2013) and magnetospheric substorms (e.g. Consolini and Chang, 2001), and in the transfer of mass, momentum, and energy in space and astrophysical plasmas. Hasegawa et al.: Dual-spacecraft reconstruction of a three-dimensional magnetic flux rope estimation of the free magnetic energy available, by comparison with reconstructed potential or linear force-free fields, and potentially make it possible to forecast where solar flares could be initiated Such reconstructions of fully 3-D fields have not been conducted by use of in situ data taken by spacecraft during a short period, while a 3-D magnetohydrostatic equilibrium field in the magnetosphere has been recovered, for example, by modelling the field using Euler potentials and using an average equatorial profile of the plasma pressure based on long-term, in situ measurements as input and empirical fields as boundary conditions Sonnerup and Hasegawa (2011) developed a novel data analysis method for the reconstruction of steady, 3-D, magnetohydrostatic structures using plasma and magnetic field data recorded by two closely spaced spacecraft, which is hereafter referred to as the SH11 method They developed and benchmarked a primitive version of the numerical code for the SH11 method, using an analytical solution of the 3-D magnetohydrostatic equations (∇ · B = 0 and ∇p = j × B).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
