Biblio

Found 5 results
Filters: Author is Albert, J.  [Clear All Filters]
2014
Authors: Li W, Mourenas D., Artemyev A., Agapitov O., Bortnik J, et al.
Title: Evidence of stronger pitch angle scattering loss caused by oblique whistler-mode waves as compared with quasi-parallel waves
Abstract: Wave normal distributions of lower-band whistler-mode waves observed outside the plasmapause exhibit two peaks; one near the parallel direction and the other at very oblique angles. We analyze a number of conjunction events between the Van Allen Probes near the equatorial plane and POES satellites at conjugate low altitudes, where lower-band whistler-mode wave amplitudes were inferred from the two-directional POES electron measurements over 30–100 keV, assuming that these waves were quasi-parallel. For conjunction events, the wave amplitudes inferred from the POES electron measurements were found to be overestimated as compared with the Van Allen Probes measurements primarily for oblique waves and quasi-parallel waves with small wave amplitudes (< ~20 pT) measured at low latitudes. This . . .
Date: 08/2014 Publisher: Geophysical Research Letters Pages: n/a - n/a DOI: 10.1002/2014GL061260 Available at: http://doi.wiley.com/10.1002/2014GL061260
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Authors: Albert J
Title: Radial diffusion simulations of the 20 September 2007 radiation belt dropout
Abstract: This is a study of a dropout of radiation belt electrons, associated with an isolated solar wind density pulse on 20 September 2007, as seen by the solid-state telescopes (SST) detectors on THEMIS (Time History of Events and Macroscale Interactions during Substorms). Omnidirectional fluxes were converted to phase space density at constant invariants M = 700 MeV G−1 and K = 0.014 RE G1/2, with the assumption of local pitch angle α ≈ 80° and using the T04 magnetic field model. The last closed drift shell, which was calculated throughout the time interval, never came within the simulation outer boundary of L* = 6. It is found, using several different models for diffusion rates, that radial diffusion alone only allows the data-driven, time-dependent boundary values at Lmax = 6 and Lmin =. . .
Date: 11/2014 Publisher: Annales Geophysicae Pages: 925 - 934 DOI: 10.5194/angeo-32-925-2014 Available at: http://www.ann-geophys.net/32/925/2014/http://www.ann-geophys.net/32/925/2014/angeo-32-925-2014.pdf
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2013
Authors: Wygant J R, Bonnell J W, Goetz K, Ergun R E, Mozer F S, et al.
Title: The Electric Field and Waves (EFW) Instruments on the Radiation Belt Storm Probes Mission
Abstract: The Electric Fields and Waves (EFW) Instruments on the two Radiation Belt Storm Probe (RBSP) spacecraft (recently renamed the Van Allen Probes) are designed to measure three dimensional quasi-static and low frequency electric fields and waves associated with the major mechanisms responsible for the acceleration of energetic charged particles in the inner magnetosphere of the Earth. For this measurement, the instrument uses two pairs of spherical double probe sensors at the ends of orthogonal centripetally deployed booms in the spin plane with tip-to-tip separations of 100 meters. The third component of the electric field is measured by two spherical sensors separated by ∼15 m, deployed at the ends of two stacer booms oppositely directed along the spin axis of the spacecraft. The instrume. . .
Date: 11/2013 Publisher: Space Science Reviews DOI: 10.1007/s11214-013-0013-7 Available at: http://link.springer.com/article/10.1007%2Fs11214-013-0013-7
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2008
Authors: Jordanova V K, Albert J, and Miyoshi Y
Title: Relativistic electron precipitation by EMIC waves from self-consistent global simulations
Abstract: [1] We study the effect of electromagnetic ion cyclotron (EMIC) wave scattering on radiation belt electrons during the large geomagnetic storm of 21 October 2001 with minimum Dst = −187 nT. We use our global physics-based model, which solves the kinetic equation for relativistic electrons and H+, O+, and He+ ions as a function of radial distance in the equatorial plane, magnetic local time, energy, and pitch angle. The model includes time-dependent convective transport and radial diffusion and all major loss processes and is coupled with a dynamic plasmasphere model. We calculate the excitation of EMIC waves self-consistently with the evolving plasma populations. Particle interactions with these waves are evaluated according to quasi-linear theory, using diffusion coefficients for a mult. . .
Date: 03/2008 Publisher: Journal of Geophysical Research DOI: 10.1029/2008JA013239 Available at: http://onlinelibrary.wiley.com/doi/10.1029/2008JA013239/abstract
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2007
Authors: Kress B T, Hudson M K, Looper M D, Albert J, Lyon J G, et al.
Title: Global MHD test particle simulations of >10 MeV radiation belt electrons during storm sudden commencement
Abstract: [1] Prior to 2003, there are two known cases where ultrarelativistic (≳10 MeV) electrons appeared in the Earth's inner zone radiation belts in association with high speed interplanetary shocks: the 24 March 1991 and the less well studied 21 February 1994 storms. During the March 1991 event electrons were injected well into the inner zone on a timescale of minutes, producing a new stably trapped radiation belt population that persisted for ∼10 years. More recently, at the end of solar cycle 23, a number of violent geomagnetic disturbances resulted in large variations in ultrarelativistic electrons in the inner zone, indicating that these events are less rare than previously thought. Here we present results from a numerical study of shock-induced transport and energization of outer zone . . .
Date: 09/2007 Publisher: Journal of Geophysical Research DOI: 10.1029/2006JA012218 Available at: http://onlinelibrary.wiley.com/doi/10.1029/2006JA012218/abstract
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