Abstract

Correlated electric field and low‐energy electron measurements are presented for two passes of Hawk‐eye 1 through the south polar cusp at 2000‐km altitude during local morning. In one case the electric field reversal coincides with the boundary of detectable 5.2‐keV electron intensities and the equatorward boundary of the cusp. In the other case the electric field reversal and the 5.2‐keV electron trapping boundary coincide, but the equatorward edge of the cusp as determined from the presence of 180‐eV electron intensities is 5° invariant latitude equatorward of the electric field reversal. We conclude that in the second case, electron intensities associated with the polar cusp populate closed dayside field lines, and hence the corresponding equatorward edge of these electron intensities is not always an indicator of the boundary between closed dayside field lines and polar cap field lines.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.