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Particle Dynamics in the Earth's Radiation Belts: Review of Current Research and Open Questions
Li, X.; Ukhorskiy, A. Y.; Fennell, J. F. +4 more
The past decade transformed our observational understanding of energetic particle processes in near-Earth space. An unprecedented suite of observational systems was in operation including the Van Allen Probes, Arase, Magnetospheric Multiscale, Time History of Events and Macroscale Interactions during Substorms, Cluster, GPS, GOES, and Los Alamos N…
Atmospheric Escape Processes and Planetary Atmospheric Evolution
Simon Wedlund, C.; Maggiolo, R.; Cessateur, G. +17 more
The habitability of the surface of any planet is determined by a complex evolution of its interior, surface, and atmosphere. The electromagnetic and particle radiation of stars drive thermal, chemical, and physical alteration of planetary atmospheres, including escape. Many known extrasolar planets experience vastly different stellar environments …
Magnetic Reconnection in the Space Sciences: Past, Present, and Future
Hesse, M.; Cassak, P. A.
Magnetic reconnection converts, often explosively, stored magnetic energy to particle energy in space and in the laboratory. Through processes operating on length scales that are tiny, it facilitates energy conversion over dimensions of, in some cases, hundreds of Earth radii. In addition, it is the mechanism behind large current disruptions in fu…
Magnetic Reconnection Inside a Flux Rope Induced by Kelvin-Helmholtz Vortices
Liu, Y.; Russell, C. T.; Escoubet, C. P. +23 more
On 5 May 2017, MMS observed a crater-type flux rope on the dawnside tailward magnetopause with fluctuations. The boundary-normal analysis shows that the fluctuations can be attributed to nonlinear Kelvin-Helmholtz (KH) waves. Reconnection signatures such as flow reversals and Joule dissipation were identified at the leading and trailing edges of t…
Do Statistical Models Capture the Dynamics of the Magnetopause During Sudden Magnetospheric Compressions?
Wild, J. A.; Milan, S. E.; Imber, S. M. +9 more
Under periods of strong solar wind driving, the magnetopause can become compressed, playing a significant role in draining electrons from the outer radiation belt. Also termed "magnetopause shadowing," this loss process has traditionally been attributed to a combination of magnetospheric compression and outward radial diffusion of electrons. Howev…
Electron Pitch-Angle Distribution in Earth's Magnetotail: Pancake, Cigar, Isotropy, Butterfly, and Rolling-Pin
Wang, Z.; Xu, Y.; Chen, G. +4 more
Electron pitch-angle distributions, including isotropy, pancake, cigar, butterfly, and recently discovered rolling-pin distributions, are crucial to understanding electron dynamics in the magnetotail. However, occurrence rates of these distributions remain unclear. Here, for the first time, we reveal the occurrence rates of these distributions in …
Effects of Fluctuating Magnetic Field on the Growth of the Kelvin-Helmholtz Instability at the Earth's Magnetopause
Hasegawa, H.; Nakamura, R.; Narita, Y. +5 more
At the Earth's magnetopause, the Kelvin-Helmholtz (KH) instability, driven by the persistent velocity shear between the magnetosheath and the magnetosphere, has been frequently observed during northward interplanetary magnetic field periods and considered as one of the most important candidates for transporting and mixing plasmas across the magnet…
Drift-Bounce Resonance Between Charged Particles and Ultralow Frequency Waves: Theory and Observations
Zong, Qiu-Gang; Liu, Ying; Zhang, Shuai +7 more
Ultralow frequency (ULF) waves have long been known to resonate with magnetospheric charged particles through their drift and bounce motions. Most research interest has focused on the resonance with drift motion, which can accelerate charged particles at very high energies. The role of the bounce motion, especially for particles with lower energie…
Outer Radiation Belt Electron Lifetime Model Based on Combined Van Allen Probes and Cluster VLF Measurements
Aryan, Homayon; Boynton, Richard; Balikhin, Michael A. +4 more
The flux of energetic electrons in the outer radiation belt shows a high variability. The interactions of electrons with very low frequency (VLF) chorus waves play a significant role in controlling the flux variation of these particles. Quantifying the effects of these interactions is crucially important for accurately modeling the global dynamics…
Evolution of High-Speed Jets and Plasmoids Downstream of the Quasi-Perpendicular Bow Shock
Gunell, H.; Hamrin, M.; Goncharov, O. +1 more
Plasma structures with enhanced dynamic pressure, density, or speed are often observed in Earth's magnetosheath. We present a statistical study of these structures, known as jets and fast plasmoids, in the magnetosheath, downstream of both the quasi-perpendicular and quasi-parallel bow shocks. Using measurements from the four Magnetospheric Multis…