Oblique Ion-Scale Magnetotail Flux Ropes Generated by Secondary Tearing Modes

Teh Wai Leong, Takuma Nakamura, Rumi Nakamura, Takayuki Umeda

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We examine Magnetospheric Multiscale observations of three ion-scale magnetic flux ropes (diameter ~6–9 ion inertial lengths) in the Earth's magnetotail reconnection diffusion region with a small guide field. During the event, the electron reconnection exhaust reversed direction together with the reversal of normal magnetic field component. After that, the three ion-scale flux ropes were observed near the ion diffusion region, in which flat-top distributions were found at the field-aligned electrons (<2 keV). The axis orientation and motion velocity of the flux ropes are determined by minimum variance analysis of the electric field component along the flux rope axis, using single-spacecraft measurements. Results show that the three flux rope axes form 13°, 55°, and 55° to the guide field direction and are mostly tilted toward the direction of the reconnecting field. These results are also validated by multiple-spacecraft analysis methods. It is found that the tilted angles agree reasonably well with the predicted angles for secondary tearing modes, suggesting that these ion-scale flux ropes are likely generated by secondary tearing instabilities as those recently found in the three-dimensional kinetic simulations of turbulent magnetic reconnection.

Original languageEnglish
JournalJournal of Geophysical Research: Space Physics
DOIs
Publication statusAccepted/In press - 1 Jan 2018

Fingerprint

magnetotails
ropes
magnetotail
Ions
ions
Fluxes
ion
spacecraft
Spacecraft
geomagnetic tail
electron
analysis of variance
tearing
electrons
Electrons
variance analysis
electric field
Magnetic flux
magnetic flux
magnetic fields

Keywords

  • magnetic flux rope
  • magnetic reconnection
  • secondary tearing instability

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Space and Planetary Science
  • Earth and Planetary Sciences (miscellaneous)
  • Palaeontology

Cite this

Oblique Ion-Scale Magnetotail Flux Ropes Generated by Secondary Tearing Modes. / Wai Leong, Teh; Nakamura, Takuma; Nakamura, Rumi; Umeda, Takayuki.

In: Journal of Geophysical Research: Space Physics, 01.01.2018.

Research output: Contribution to journalArticle

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