SM013-03
Evidence of low-energy electron scattering and ionospheric precipitation by time domain structures

Tuesday, 8 December 2020: 19:09
Virtual
Yangyang Shen1, Anton Artemyev2, Xiaojia Zhang3, Ivan Vasko4, Andrei Runov5, Vassilis Angelopoulos5 and David J Knudsen6, (1)University of California Los Angeles, Los Angeles, CA, United States, (2)University of California Los Angeles, Earth, Planetary, and Space Sciences, Los Angeles, CA, United States, (3)IGPP, UCLA, Los Angeles, CA, United States, (4)Space Science Lab, UC berkeley, Moscow, CA, United States, (5)University of California Los Angeles, Department of Earth, Planetary, and Space Sciences and Institute of Geophysics and Planetary Physics, Los Angeles, CA, United States, (6)University of Calgary, Calgary, AB, Canada
Recorded Presentation
Abstract:
Plasma sheet electron precipitation is critical in magnetosphere-ionosphere coupling and has long been attributed to electron scattering by whistler-mode and electron cyclotron harmonic waves. Recent observations have revealed that time domain structures (TDSs) that appear as broadband electrostatic fluctuations may also scatter plasma sheet electrons. However, there has been no observational evidence of TDS scattering electrons into the ionosphere. This study presents such evidence from conjugate observations between The Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission and the low-altitude Enhanced Polar Outflow Probe (e-POP) spacecraft. During the five events presented, THEMIS observed intense electron injections accompanied by TDSs, while e-POP captured precipitation of plasma-sheet electrons with energies ~100--325 eV over a broad pitch-angle range. The observed TDSs can efficiently scatter these electrons exceeding the strong diffusion limit. Our results suggest that TDSs may contribute to plasma sheet electron scattering around times of injections.
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