Evidence for the core field polarity of magnetic flux ropes against the reconnection guide field

Teh Wai Leong, Mardina Abdullah, Alina Marie Hasbi

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We present the observational evidence by Time History of Events and Macroscale Interactions during Substorms (THEMIS)-D spacecraft to demonstrate that magnetic flux rope can have a core field polarity opposite to the guide field during asymmetric reconnection with a high magnetic shear across the magnetopause. In the presented event, a bipolar reconnection outflow was observed at the magnetopause, across which the magnetic shear was ~149° corresponding to a predicted guide field BG = −15.6 nT. The ratios for magnetic field strength and ion density between the magnetospheric and magnetosheath sides of the magnetopause were ~1.6 and ~0.15, respectively. During the event, the component of magnetic field along the M axis (the intermediate variance direction) remained negative and stable for most of the time, and its mean value agreed with the BG. Two magnetic flux ropes with a strong core field were identified, but one flux rope had a core field polarity against the guide field BG. Our finding differs from current theoretical simulations that the core field polarity of the flux ropes inherits from the guide field.

Original languageEnglish
Pages (from-to)8979-8983
Number of pages5
JournalJournal of Geophysical Research A: Space Physics
Volume119
Issue number11
DOIs
Publication statusPublished - 2014

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Cable cores
ropes
Magnetopause
magnetopause
Magnetic flux
magnetic flux
polarity
magnetic field
magnetic fields
shears
Magnetic fields
Fluxes
shear
magnetosheath
outflow
spacecraft
Spacecraft
field strength
ion
histories

Keywords

  • magnetic flux rope
  • magnetic reconnection
  • magnetopause

ASJC Scopus subject areas

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

Cite this

Evidence for the core field polarity of magnetic flux ropes against the reconnection guide field. / Wai Leong, Teh; Abdullah, Mardina; Hasbi, Alina Marie.

In: Journal of Geophysical Research A: Space Physics, Vol. 119, No. 11, 2014, p. 8979-8983.

Research output: Contribution to journalArticle

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