Search Publications
Electron scattering by magnetosonic waves in the inner magnetosphere
Hospodarsky, G. B.; Kurth, W. S.; Ma, Qianli +4 more
We investigate the importance of electron scattering by magnetosonic waves in the Earth's inner magnetosphere. A statistical survey of the magnetosonic wave amplitude and wave frequency spectrum, as a function of geomagnetic activity, is performed using the Van Allen Probes wave measurements and is found to be generally consistent with the wave di…
Highly relativistic radiation belt electron acceleration, transport, and loss: Large solar storm events of March and June 2015
Baker, D. N.; Kanekal, S. G.; Zhao, H. +12 more
Two of the largest geomagnetic storms of the last decade were witnessed in 2015. On 17 March 2015, a coronal mass ejection-driven event occurred with a Dst (storm time ring current index) value reaching -223 nT. On 22 June 2015 another strong storm (Dst reaching -204 nT) was recorded. These two storms each produced almost total loss of radiation b…
Electrostatic solitary waves and electrostatic waves at the magnetopause
André, M.; Vaivads, A.; Khotyaintsev, Yu. V. +1 more
Electrostatic solitary waves (ESWs) are characterized by localized bipolar electric fields parallel to the magnetic field and are frequently observed in space plasmas. In this paper a study of ESWs and field-aligned electrostatic waves, which do not exhibit localized bipolar fields, near the magnetopause is presented using the Cluster spacecraft. …
Suprathermal particle energization in dipolarization fronts: Particle-in-cell simulations
Angelopoulos, V.; Fu, Huishan; Lu, San
Within dipolarization fronts (DFs) in the Earth's magnetotail, significant magnetic energy is converted to plasma energy, and a significant portion of the electrons and ions therein are accelerated to suprathermal energies. The mechanism that produces these suprathermal particles while simultaneously reducing magnetic field energy is poorly unders…
Identifying magnetic reconnection events using the FOTE method
Vaivads, A.; Cao, J. B.; Dunlop, M. +8 more
A magnetic reconnection event detected by Cluster is analyzed using three methods: Single-spacecraft Inference based on Flow-reversal Sequence (SIFS), Multispacecraft Inference based on Timing a Structure (MITS), and the First-Order Taylor Expansion (FOTE). Using the SIFS method, we find that the reconnection structure is an X line; while using th…
The plasma structure of coronal hole solar wind: Origins and evolution
Borovsky, Joseph E.
Whereas slow solar wind is known to be highly structured, the fast (coronal hole origin) wind is usually considered to be homogeneous. Using measurements from Helios 1 + 2, ACE, Wind, and Ulysses, structure in the coronal hole origin solar wind is examined from 0.3 AU to 2.3 AU. Care is taken to collect and analyze intervals of "unperturbed corona…
A model for stealth coronal mass ejections
Luhmann, J. G.; Li, Y.; Masson, S. +4 more
Stealth coronal mass ejections (CMEs) are events in which there are almost no observable signatures of the CME eruption in the low corona but often a well-resolved slow flux rope CME observed in the coronagraph data. We present results from a three-dimensional numerical magnetohydrodynamics (MHD) simulation of the 1-2 June 2008 slow streamer blowo…
Predicting the amplitude and hemispheric asymmetry of solar cycle 25 with surface flux transport
Hathaway, David H.; Upton, Lisa A.
Evidence strongly indicates that the strength of the Sun's polar fields near the time of a sunspot cycle minimum determines the strength of the following solar activity cycle. We use our Advective Flux Transport code, with flows well constrained by observations, to simulate the evolution of the Sun's polar magnetic fields from early 2016 to the en…
Characterizing cometary electrons with kappa distributions
Frahm, R. A.; Eriksson, A.; Henri, P. +17 more
The Rosetta spacecraft has escorted comet 67P/Churyumov-Gerasimenko since 6 August 2014 and has offered an unprecedented opportunity to study plasma physics in the coma. We have used this opportunity to make the first characterization of cometary electrons with kappa distributions. Two three-dimensional kappa functions were fit to the observations…
Whistler emission in the separatrix regions of asymmetric magnetic reconnection
André, M.; Vaivads, A.; Khotyaintsev, Yu. V. +1 more
At Earth's dayside magnetopause asymmetric magnetic reconnection occurs between the cold dense magnetosheath plasma and the hot tenuous magnetospheric plasma, which differs significantly from symmetric reconnection. During magnetic reconnection the separatrix regions are potentially unstable to a variety of instabilities. In this paper observation…