27 July 2015 to 21 August 2015
Nordita, Stockholm
Europe/Stockholm timezone

Observations of flux ropes associated with magnetic reconnection in the magnetotail

Not scheduled
132:028 (Nordita, Stockholm)

132:028

Nordita, Stockholm

Poster Workshop, August 10-14

Speaker

Dr Shiyong Huang (Laboratoire de Physique des Plasmas, CNRS-Ecole Polytechnique-UPMC, Palaiseau, France)

Description

Magnetic reconnection is a fundamental physical process that enables the rapid transfer of magnetic energy into plasma kinetic and thermal energy in the laboratory, astrophysical and space plasma. Flux ropes have been suggested to play important role in controlling the micro-scale physics of magnetic reconnection and electron acceleration. In this presentation, we report the observations of flux ropes associated with magnetic reconnection in the magnetotail based on the Cluster multi-spacecraft data. Firstly, two consecutive magnetic flux ropes, separated by less than 30 s (Δt < 30 s), are observed within one magnetic reconnection diffusion region without strong guide field. In spite of the small but non-trivial global scale negative guide field (–By), there exists a directional change of the core fields of two flux ropes, i.e. –By for the first one, and +By for the second one. This is inconsistent with any theory and simulations. Therefore, we suggest that the core field of flux ropes is formed by compression of the local preexisting By, and that the directional change of core field is due to the change of local preexisting By. Such a change in ambient By might be caused by some microscale physics. Secondary, we will present in-situ observations of a small scale flux rope locally formed at the separatrix region of magnetic reconnection without large guide field. Bidirectional electron beams (cold and hot beams) and density cavity accompanied by intense wave activities substantiate the crossing of the separatrix region. Density compression and one parallel electron beam are detected inside the flux rope. We suggest that this flux rope is locally generated at the separatrix region due to the tearing instability within the separatrix current layer. This observation sheds new light on the 3D picture of magnetic reconnection in space plasma.

Primary author

Dr Shiyong Huang (Laboratoire de Physique des Plasmas, CNRS-Ecole Polytechnique-UPMC, Palaiseau, France)

Co-authors

A. Retino (Laboratoire de Physique des Plasmas, CNRS-Ecole Polytechnique-UPMC, Palaiseau, France) A. Vaivads (Swedish Institute of Space Physics, Uppsala, Sweden) D. D. Wang (School of Electronic Information, Wuhan University, Wuhan, China) F. Sahraoui (Laboratoire de Physique des Plasmas, CNRS-Ecole Polytechnique-UPMC, Palaiseau, France) G. L. Li (Space Science Center, University of New Hampshire, Durham, New Hampshire, USA) H. Karimabadi (University of California San Diego, La Jolla, California, USA) H. S. Fu (Space Science Institute, School of Astronautics, Beihang University, Beijing, China) M. Zhou (Institute of Space Science and Technology, Nanchang University, Nanchang, China) S. Fu (School of Electronic Information, Wuhan University, Wuhan, China) T. D. Phan (Space Sciences Laboratory, University of California, Berkeley, California, USA) W. Daughton (Los Alamos National Laboratory, Los Alamos, New Mexico USA) X. H. Deng (Institute of Space Science and Technology, Nanchang University, Nanchang, China) Y. Pang (Institute of Space Science and Technology, Nanchang University, Nanchang, China) Z. G. Yuan (School of Electronic Information, Wuhan University, Wuhan, China)

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