Search Publications
Intermittent energy dissipation by turbulent reconnection
Eastwood, J. P.; André, M.; Vaivads, A. +5 more
Magnetic reconnection—the process responsible for many explosive phenomena in both nature and laboratory—is efficient at dissipating magnetic energy into particle energy. To date, exactly how this dissipation happens remains unclear, owing to the scarcity of multipoint measurements of the "diffusion region" at the sub-ion scale. Here we report suc…
Explaining the rolling-pin distribution of suprathermal electrons behind dipolarization fronts
Cao, J. B.; Xu, Y.; Fu, H. S. +2 more
The rolling-pin distribution of suprathermal electrons (40-200 keV), showing electron pitch angles primarily at 0°, 90°, and 180°, has recently been reported behind dipolarization fronts (DFs) both in observations and simulations. The formation of such type of distribution, however, has been unclear so far. In this study, we present an observation…
Kinetic Alfvén wave explanation of the Hall fields in magnetic reconnection
Lavraud, Benoit; Wang, Chi; Dai, Lei +4 more
Magnetic reconnection is initiated in a small diffusion region but can drive global-scale dynamics in Earth's magnetosphere, solar flares, and astrophysical systems. Understanding the processes at work in the diffusion region remains a main challenge in space plasma physics. Recent in situ observations from Magnetospheric Multiscale and Time Histo…
Energy conversion at dipolarization fronts
André, M.; Vaivads, A.; Khotyaintsev, Yu. V. +2 more
We use multispacecraft observations by Cluster in the Earth's magnetotail and 3-D particle-in-cell simulations to investigate conversion of electromagnetic energy at the front of a fast plasma jet. We find that the major energy conversion is happening in the Earth (laboratory) frame, where the electromagnetic energy is being transferred from the e…
Rapid Pitch Angle Evolution of Suprathermal Electrons Behind Dipolarization Fronts
Daly, P. W.; Cao, J. B.; Xu, Y. +4 more
The pitch angle distribution (PAD) of suprathermal electrons can have both spatial and temporal evolution in the magnetotail and theoretically can be an indication of electron energization/cooling processes there. So far, the spatial evolution of PAD has been well studied, leaving the temporal evolution as an open question. To reveal the temporal …
Global observations of magnetospheric high-m poloidal waves during the 22 June 2015 magnetic storm
Russell, C. T.; Anderson, B. J.; Nakamura, R. +12 more
We report global observations of high-m poloidal waves during the recovery phase of the 22 June 2015 magnetic storm from a constellation of widely spaced satellites of five missions including Magnetospheric Multiscale (MMS), Van Allen Probes, Time History of Events and Macroscale Interactions during Substorm (THEMIS), Cluster, and Geostationary Op…
Global ULF waves generated by a hot flow anomaly
Zhao, L. L.; Zhang, H.; Zong, Q. G.
Hot flow anomalies (HFAs), which are frequently observed near Earth's bow shock, are phenomena resulting from the interaction between interplanetary discontinuities and Earth's bow shock. Such transient phenomena upstream the bow shock can cause significant deformation of the bow shock and the magnetosphere, generating traveling convection vortice…
Quasilinear analysis of saturation properties of broadband whistler mode waves
Chen, L.; Liu, X.; Wang, S. +2 more
Saturation properties of parallel propagating broadband whistler mode waves are investigated using quasilinear theory. By assuming that the electron distribution stays bi-Maxwellian, we combine the previously obtained energy equation of quasilinear theory with wave equation to self-consistently model the excitation of broadband whistler waves. The…
Ion hole formation and nonlinear generation of electromagnetic ion cyclotron waves: THEMIS observations
Miyoshi, Yoshizumi; Kasahara, Satoshi; Asamura, Kazushi +6 more
Electromagnetic plasma waves are thought to be responsible for energy exchange between charged particles in space plasmas. Such an energy exchange process is evidenced by phase space holes identified in the ion distribution function and measurements of the dot product of the plasma wave electric field and the ion velocity. We develop a method to i…
Growth rate measurement of ULF waves in the ion foreshock
Hietala, H.; Angelopoulos, V.; Dorfman, S. +1 more
We report the first satellite measurement of the ultralow frequency (ULF) wave growth rate in the upstream region of the Earth's bow shock. We employ the two identical ARTEMIS spacecraft orbiting the Moon to characterize crescent-shaped reflected ion beams and relatively monochromatic ULF waves. The event presented here features spacecraft separat…