Premium
On the Dawn‐Dusk Asymmetry of the Kelvin‐Helmholtz Instability Between 2007 and 2013
Author(s) -
Henry Z. W.,
Nykyri K.,
Moore T. W.,
Dimmock A. P.,
Ma X.
Publication year - 2017
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2017ja024548
Subject(s) - instability , asymmetry , spiral (railway) , physics , geophysics , interplanetary magnetic field , orientation (vector space) , magnetic field , geodesy , astrophysics , geology , mechanics , solar wind , mathematics , geometry , mathematical analysis , quantum mechanics
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 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 dawnside during PS orientation, and although a preference to the duskside 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 Kelvin‐Helmholtz instability (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.