On the Dawn-Dusk Asymmetry of the Kelvin-Helmholtz Instability Between 2007 and 2013

Z. W. Henry, K. Nykyri, T. W. Moore, A. P. Dimmock, X. Ma, Xuanye Ma

Research output: Contribution to journalArticlepeer-review

Abstract

Using data from Time History of Events and Macroscale Interactions during Substorms (THEMIS), a statistical study was performed to determine whether a dawn-dusk asymmetry exists in the occurrence rates of the Kelvin-Helmholtz (KH) instability during Parker-Spiral (PS) and Ortho-Parker-Spiral (OPS) orientations of the interplanetary magnetic field (IMF). It is determined from the data that there is a strong preference toward the dawn side during PS orientation, and although a preference to the dusk side during OPS is suggested, this requires further study for an unambiguous confirmation. The uncertainty in the OPS result is due to a low number of events which satisfied our selection criteria. Because IMF is statistically in PS orientation, the KHI preference for the dawn-flank during this orientation may help explain the origin of the plasma sheet asymmetry of cold-component ions because it has been shown that KHI can drive kinetic-scale wave activity capable of ion heating.

Original languageAmerican English
JournalJournal of Geophysical Research: Space Physics
Volume122
DOIs
StatePublished - Oct 16 2017

Keywords

  • Kelvin-Helmholtz instability
  • dawn-dusk asymmetry
  • magnetosphere
  • magnetosheath
  • plasma entry
  • low-latitude boundary layer

Disciplines

  • Astrophysics and Astronomy
  • Physical Processes
  • Physical Sciences and Mathematics
  • The Sun and the Solar System

Cite this