JpGU-AGU Joint Meeting 2020

Presentation information

[E] Oral

P (Space and Planetary Sciences ) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM21] Surprises from the Subauroral Zone: Synthesizing Ground and Space-Based Observations and Theory

convener:Connors Martin G(Athabasca University), Kazuo Shiokawa(Institute for Space-Earth Environmental Research, Nagoya University)

[PEM21-01] Magnetospheric-ionosphere dynamics associated with STEVE

★Invited Papers

*Toshi Nishimura1, Jian Yang2, Eric Donovan3, Vassilis Angelopoulos4, Nozomu Nishitani5 (1.Boston University, 2.Southern University of Science and Technology, 3.University of Calgary, 4.University of California, Los Angeles, 5.Nagoya University)

Keywords:STEVE, SAID

We present three STEVE (strong thermal emission velocity enhancement) events in conjunction with THEMIS in the magnetosphere, and DMSP and Swarm in the ionosphere, for determining equatorial and inter-hemispheric signatures of the STEVE purple/mauve arc and picket fence. Both types of STEVE emissions are associated with SAID (subauroral ion drifts), electron heating, and plasma waves. The magnetosphere observations show structured electrons and flows, and waves just outside the plasmasphere. Interestingly, the event with the picket fence had a >keV electron structure detached from the electron plasma sheet, while the event with only the mauve arc did not have precipitation or ultra-violet emission. We suggest that the electron precipitation drives the picket fence, and heating drives the mauve emission. We further present particle transport processes in the magnetosphere and discuss how magnetosphere conditions that are favorable to STEVE occur.