Articles | Volume 33, issue 6
https://doi.org/10.5194/angeo-33-719-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.Electron-scale nested quadrupole Hall field in Cluster observations of magnetic reconnection
Abstract. This paper presents the first evidence of a new and unique feature of spontaneous reconnection at multiple sites in electron current sheet, viz. a "nested quadrupole" structure of the Hall field at electron scales, in Cluster observations. The new nested quadrupole is a consequence of electron-scale processes in reconnection. Whistler response of the upstream plasma to the interaction of electron flows from neighboring reconnection sites produces a large-scale quadrupole Hall field enclosing the quadrupole fields of the multiple sites, thus forming a nested structure. Electron-magnetohydrodynamic simulations of an electron current sheet yields a mechanism of the formation of a nested quadrupole.