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 language | American English |
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Journal | Journal of Geophysical Research: Space Physics |
Volume | 122 |
DOIs | |
State | Published - 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