TY - JOUR
T1 - Identifying STEVE's Magnetospheric Driver Using Conjugate Observations in the Magnetosphere and on the Ground
AU - Chu, Xiangning
AU - Malaspina, David
AU - Gallardo-Lacourt, Bea
AU - Liang, Jun
AU - Andersson, Laila
AU - Ma, Qianli
AU - Artemyev, Anton
AU - Liu, Jiang
AU - Ergun, Robert E.
AU - Thaller, Scott
AU - Akbari, Hassanali
AU - Zhao, Hong
AU - Larsen, Brian
AU - Reeves, Geoffrey
AU - Wygant, John
AU - Breneman, Aaron
AU - Tian, Sheng
AU - Connors, Martin
AU - Donovan, Eric
AU - Archer, William
AU - MacDonald, Elizabeth A.
N1 - Publisher Copyright:
©2019. American Geophysical Union. All Rights Reserved.
PY - 2019/11/28
Y1 - 2019/11/28
N2 - The magnetospheric driver of strong thermal emission velocity enhancement (STEVE) is investigated using conjugate observations when Van Allen Probes' footprint directly crossed both STEVE and stable red aurora (SAR) arc. In the ionosphere, STEVE is associated with subauroral ion drift features, including electron temperature peak, density gradient, and westward ion flow. The SAR arc at lower latitudes corresponds to regions inside the plasmapause with isotropic plasma heating, which causes redline-only SAR emission via heat conduction. STEVE corresponds to the sharp plasmapause boundary containing quasi-static subauroral ion drift electric field and parallel-accelerated electrons by kinetic Alfvén waves. These parallel electrons could precipitate and be accelerated via auroral acceleration processes powered by Alfvén waves propagating along the magnetic field with the plasmapause as a waveguide. The electron precipitation, superimposed on the heat conduction, could explain multiwavelength continuous STEVE emission. The green picket-fence emissions are likely optical manifestations of electron precipitation associated with wave structures traveling along the plasmapause.
AB - The magnetospheric driver of strong thermal emission velocity enhancement (STEVE) is investigated using conjugate observations when Van Allen Probes' footprint directly crossed both STEVE and stable red aurora (SAR) arc. In the ionosphere, STEVE is associated with subauroral ion drift features, including electron temperature peak, density gradient, and westward ion flow. The SAR arc at lower latitudes corresponds to regions inside the plasmapause with isotropic plasma heating, which causes redline-only SAR emission via heat conduction. STEVE corresponds to the sharp plasmapause boundary containing quasi-static subauroral ion drift electric field and parallel-accelerated electrons by kinetic Alfvén waves. These parallel electrons could precipitate and be accelerated via auroral acceleration processes powered by Alfvén waves propagating along the magnetic field with the plasmapause as a waveguide. The electron precipitation, superimposed on the heat conduction, could explain multiwavelength continuous STEVE emission. The green picket-fence emissions are likely optical manifestations of electron precipitation associated with wave structures traveling along the plasmapause.
KW - STEVE
KW - aurora
KW - kinetic Alfven wave
KW - plasmapause
KW - stable red auroral arc
KW - subauroral ion drift
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U2 - 10.1029/2019GL082789
DO - 10.1029/2019GL082789
M3 - Article
AN - SCOPUS:85075445603
SN - 0094-8276
VL - 46
SP - 12665
EP - 12674
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 22
ER -