Search Publications
Global model of lower band and upper band chorus from multiple satellite observations
Meredith, Nigel P.; Horne, Richard B.; Thorne, Richard M. +4 more
Gyroresonant wave particle interactions with whistler mode chorus play a fundamental role in the dynamics of the Earth's radiation belts and inner magnetosphere, affecting both the acceleration and loss of radiation belt electrons. Knowledge of the variability of chorus wave power as a function of both spatial location and geomagnetic activity, re…
Pitch angle distribution of suprathermal electrons behind dipolarization fronts: A statistical overview
Daly, P. W.; André, M.; Vaivads, A. +5 more
We examine the pitch angle distribution (PAD) of suprathermal electrons (>40 keV) inside the flux pileup regions (FPRs) that are located behind the dipolarization fronts (DFs), in order to better understand the particle energization mechanisms operating therein. The 303 earthward-propagating DFs observed during 9 years (2001-2009) by Cluster 1 …
Nonlinear pitch angle scattering of relativistic electrons by EMIC waves in the inner magnetosphere
Omura, Yoshiharu; Zhao, Qinghua
We derive the second-order resonance condition for interaction between a relativistic electron and a coherent Electromagnetic Ion Cyclotron (EMIC) wave with a variable frequency. We perform test particle simulations of relativistic electrons interacting with EMIC waves with a fixed frequency and a rising-tone frequency such as EMIC triggered emiss…
Magnetosheath pressure pulses: Generation downstream of the bow shock from solar wind discontinuities
Eastwood, J. P.; Horbury, T. S.; Archer, M. O.
We present multipoint Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations of transient dynamic pressure pulses in the magnetosheath 3-10 times the background in amplitude, due to enhancements in both the ion density and velocity. Their spatial dimensions are of the order of ∼1 RE parallel to the flo…
The location of reconnection at the magnetopause: Testing the maximum magnetic shear model with THEMIS observations
Fuselier, S. A.; Phan, T. D.; Trattner, K. J. +1 more
Reconnection at the Earth's magnetopause is the mechanism by which magnetic fields in different regions change topology to create open magnetic field lines that allow energy and momentum to flow into the magnetosphere. One of the long-standing open questions about magnetic reconnection is the location of the reconnection line. There are two reconn…
Magnetospheric location of the equatorward prebreakup arc
Nakamura, R.; Sergeev, V.; Nishimura, Y. +3 more
We address the long-standing problem of the location and origin of the equatorwardmost Pre-Breakup auroral Arc (PBA) by combining energetic particle observations from NOAA Polar Operational Environmental Satellites (POES) overpasses of prebreakup arcs with auroral imaging and magnetospheric observations from the Time History of Events and Macrosca…
Timescales for electron quasi-linear diffusion by parallel and oblique lower-band chorus waves
Artemyev, A. V.; Agapitov, O. V.; Krasnoselskikh, V. V. +2 more
The loss of relativistic electrons from the Earth's radiation belts can be described in terms of the quasi-linear pitch angle diffusion by cyclotron-resonant waves, provided that their frequency spectrum is broad enough. Chorus waves at large wave-normal angles with respect to the magnetic field are often present in CLUSTER and THEMIS measurements…
Energetic particle injections to geostationary orbit: Relationship to flow bursts and magnetospheric state
Nakamura, R.; Sergeev, V. A.; Chernyaev, I. A. +5 more
To address the mechanism and factors controlling the injection of energetic particles to the geostationary orbit (GEO), we analyzed the appearance of injections at the GEO drift shell as observed by LANL spacecraft in the cases where the flow bursts and associated transient dipolarization were detected at the entry to the inner magnetosphere, in t…
The first in situ observation of Kelvin-Helmholtz waves at high-latitude magnetopause during strongly dawnward interplanetary magnetic field conditions
ViñAs, A. F.; Goldstein, M. L.; Wang, Y. +3 more
We report the first in situ observation of high-latitude magnetopause (near the northern duskward cusp) Kelvin-Helmholtz waves (KHW) by Cluster on January 12, 2003, under strongly dawnward interplanetary magnetic field (IMF) conditions. The fluctuations unstable to Kelvin-Helmholtz instability (KHI) are found to propagate mostly tailward, i.e., al…
Three-dimensional ray tracing of fast magnetosonic waves
Xiao, Fuliang; Zhou, Qinghua; He, Zhaoguo +1 more
A three dimensional ray tracing of fast magnetosonic (MS) waves is first performed by using a global core density model and a field-aligned density model. Simulating results show that MS waves are primarily confined within a few degrees of the geomagnetic equator due to magnetospheric reflection. MS waves originating from different L-shells on the…