2006/06/30 by C. J. Xiao, Chijie Xiao, X. G. Wang +20 · 6 citations
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Geomagnetism and Paleomagnetism Studies #Ionosphere and magnetosphere dynamics #Solar and Space Plasma Dynamics #physics.plasm-ph #physics.space-ph
paper · pdf · doi:10.1038/nphys342
published as Nature Physics, 2, 478-483, 2006 · 14 pages, 4 figures
openalex publication_date 2006/07/01 · arxiv created 2007/06/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Magnetic reconnection is one of the most important processes in astrophysical, space and laboratory plasmas. Identifying the structure around the point at which the magnetic field lines break and subsequently reform, known as the magnetic null point, is crucial to improving our understanding reconnection. But owing to the inherently three-dimensional nature of this process, magnetic nulls are only detectable through measurements obtained simultaneously from at least four points in space. Using data collected by the four spacecraft of the Cluster constellation as they traversed a diffusion region in the Earth's magnetotail on 15 September, 2001, we report here the first in situ evidence for the structure of an isolated magnetic null. The results indicate that it has a positive-spiral structure whose spatial extent is of the same order as the local ion inertial length scale, suggesting that the Hall effect could play an important role in 3D reconnection dynamics.