Search Publications
Consequences of geomagnetic activity on energization and loss of radiation belt electrons by oblique chorus waves
Krasnoselskikh, V.; Artemyev, A. V.; Agapitov, O. V. +1 more
Statistics of amplitudes and obliquity of lower band chorus whistler mode waves have been obtained from Cluster measurements in Earth's outer radiation belt and fitted as functions of L, latitude, magnetic local time, and three geomagnetic activity ranges for Dst∈[+10,-80] nT. Very oblique chorus waves have generally a much smaller average intensi…
The kinetic ballooning/interchange instability as a source of dipolarization fronts and auroral streamers
Pritchett, P. L.; Coroniti, F. V.; Nishimura, Y.
The possibility that the dipolarization fronts (DFs) observed in the plasma sheet could be produced by the ballooning/interchange instability is explored using three-dimensional electromagnetic particle-in-cell simulations. The localized interchange heads produced in the nonlinear stage of the instability exhibit the main near-equatorial propertie…
Interaction of magnetic reconnection and Kelvin-Helmholtz modes for large magnetic shear: 1. Kelvin-Helmholtz trigger
Ma, Xuanye; Otto, Antonius; Delamere, Peter A.
At the Earth's magnetopause, both magnetic reconnection and the Kelvin-Helmholtz (KH) instability can operate simultaneously for southward interplanetary magnetic field conditions. The dynamic evolution of such a system can be expected to depend on the importance of KH wave evolution versus reconnection and therefore on the respective initial pert…
Magnetic reconnection, buoyancy, and flapping motions in magnetotail explosions
Merkin, V. G.; Sitnov, M. I.; Mauk, B. H. +5 more
A key process in the interaction of magnetospheres with the solar wind is the explosive release of energy stored in the magnetotail. Based on observational evidence, magnetic reconnection is widely believed to be responsible. However, the very possibility of spontaneous reconnection in collisionless magnetotail plasmas has been questioned in kinet…
The substorm current wedge: Further insights from MHD simulations
Hesse, M.; Birn, J.
Using a recent magnetohydrodynamic simulation of magnetotail dynamics, we further investigate the buildup and evolution of the substorm current wedge (SCW), resulting from flow bursts generated by near-tail reconnection. Each flow burst generates an individual current wedge, which includes the reduction of cross-tail current and the diversion to r…
Observation of large-amplitude magnetosonic waves at dipolarization fronts
Nishimura, Yukitoshi; Yuan, Zhigang; Huang, Shiyong +6 more
Various plasma waves have been observed in the vicinity of dipolarization fronts (DFs) and the rarefaction regions behind them. It was suggested that these waves not only play crucial roles in regulating particle kinetics at the DFs but also may potentially affect the large-scale dynamics of the magnetotail. In this paper, we present the observati…
Wave-particle interactions during a dipolarization front event
Goldstein, M. L.; Hwang, K. -J.; F. -Viñas, A. +2 more
We present Cluster observations of wave-particle interactions during an earthward propagating dipolarization front (DF) and associated fast plasma bulk flows detected at the central current sheet in Earth's magnetotail. During this period, flux tubes behind the DF frequently contain more energetic or hotter ions than did the preexisting flux tubes…
On the origin of pressure and magnetic perturbations ahead of dipolarization fronts
Runov, A.; Angelopoulos, V.; Zhou, Xu-Zhi +2 more
Dipolarization fronts (DFs), earthward-propagating structures in the Earth's magnetotail current sheet with sharp enhancements of the northward magnetic field Bz, are typically preceded by minor decreases in Bz. Other characteristic DF precursor signatures, including earthward flows and plasma density/pressure enhancements, h…
Energetic electron bursts in the plasma sheet and their relation with BBFs
Cao, J. B.; Dunlop, M.; Wang, Z. Q. +1 more
We studied energetic electron bursts (EEBs) (40-250 keV) in the plasma sheet (PS) and their relation to bursty bulk flows (BBFs) using the data recorded by Cluster from 2001 to 2009. The EEBs in the PS can be classified into four types. Three types of EEBs are dispersionless, including EEBs accompanied with BBFs (V > 250 km/s) but without dipol…
Terrestrial lion roars and non-Maxwellian distribution
Schwartz, S. J.; Yoon, P. H.; Masood, W. +3 more
Lion roars are low-frequency (∼100 Hz) whistler waves frequently observed in the Earth's magnetosheath. By analyzing both wave and electron data from the Cluster spacecraft, and comparing with linear Vlasov kinetic theory, Masood et al. (2006) investigated the underlying cause of the lion roar generation. However, the analysis based upon the bi-Ma…