Van Allen Probes Bibliography is from August 2012 through September 2021 Notice:

Found 17 entries in the Bibliography.
Showing entries from 1 through 17
2007 
Dynamic evolution of energetic outer zone electrons due to waveparticle interactions during storms [1] Relativistic electrons in the outer radiation belt are subjected to pitch angle and energy diffusion by chorus, electromagnetic ion cyclotron (EMIC), and hiss waves. Using quasilinear diffusion coefficients for cyclotron resonance with fieldaligned waves, we examine whether the resonant interactions with chorus waves produce a net acceleration or loss of relativistic electrons. We also examine the effect of pitch angle scattering by EMIC and hiss waves during the main and recovery phases of a storm. The numerical simul ... Li, W.; Shprits, Y; Thorne, R.; Published by: Journal of Geophysical Research Published on: 10/2007 YEAR: 2007 DOI: 10.1029/2007JA012368 
Slot region electron loss timescales due to plasmaspheric hiss and lightninggenerated whistlers [1] Energetic electrons (E > 100 keV) in the Earth\textquoterights radiation belts undergo Dopplershifted cyclotron resonant interactions with a variety of whistler mode waves leading to pitch angle scattering and subsequent loss to the atmosphere. In this study we assess the relative importance of plasmaspheric hiss and lightninggenerated whistlers in the slot region and beyond. Electron loss timescales are determined using the Pitch Angle and energy Diffusion of Ions and Electrons (PADIE) code with global models of the s ... Meredith, Nigel; Horne, Richard; Glauert, Sarah; Anderson, Roger; Published by: Journal of Geophysical Research Published on: 08/2007 YEAR: 2007 DOI: 10.1029/2007JA012413 
Review of radiation belt relativistic electron losses We present a brief review of radiation belt electron losses which are vitally important for controlling the dynamics of the radiation belts. A historical overview of early observations is presented, followed by a brief description of important known electron loss mechanisms. We describe key theoretical results and observations related to pitchangle scattering by resonant interaction with plasmaspheric hiss, whistlermode chorus and electromagnetic ion cyclotron waves, and review recent work on magnetopause losses. In partic ... Published by: Journal of Atmospheric and SolarTerrestrial Physics Published on: 03/2007 YEAR: 2007 DOI: 10.1016/j.jastp.2006.06.019 
2006 
The relativistic electron dropout event on 20 November 2003 is studied using data from a number of satellites including SAMPEX, HEO, ACE, POES, and FAST. The observations suggest that the dropout may have been caused by two separate mechanisms that operate at high and low Lshells, respectively, with a separation at L \~ 5. At high Lshells (L > 5), the dropout is approximately independent of energy and consistent with losses to the magnetopause aided by the Dst effect and outward radial diffusion which can deplete relativis ... Bortnik, J.; Thorne, R.; O\textquoterightBrien, T.; Green, J.; Strangeway, R.; Shprits, Y; Baker, D.; Published by: Journal of Geophysical Research Published on: 12/2006 YEAR: 2006 DOI: 10.1029/2006JA011802 
Energetic outer zone electron loss timescales during low geomagnetic activity Following enhanced magnetic activity the fluxes of energetic electrons in the Earth\textquoterights outer radiation belt gradually decay to quiettime levels. We use CRRES observations to estimate the energetic electron loss timescales and to identify the principal loss mechanisms. Gradual loss of energetic electrons in the region 3.0 <= L <= 5.0 occurs during quiet periods (Kp < 3) following enhanced magnetic activity on timescales ranging from 1.5 to 3.5 days for 214 keV electrons to 5.5 to 6.5 days for 1.09 MeV electrons ... Meredith, Nigel; Horne, Richard; Glauert, Sarah; Thorne, Richard; Summers, D.; Albert, Jay; Anderson, Roger; Published by: Journal of Geophysical Research Published on: 05/2006 YEAR: 2006 DOI: 10.1029/2005JA011516 
2005 
Timescale for MeV electron microburst loss during geomagnetic storms Energetic electrons in the outer radiation belt can resonate with intense bursts of whistlermode chorus emission leading to microburst precipitation into the atmosphere. The timescale for removal of outer zone MeV electrons during the main phase of the October 1998 magnetic storm has been computed by comparing the rate of microburst loss observed on SAMPEX with trapped flux levels observed on Polar. Effective lifetimes are comparable to a day and are relatively independent of L shell. The lifetimes have also been evaluated ... Thorne, R.; O\textquoterightBrien, T.; Shprits, Y; Summers, D.; Horne, R.; Published by: Journal of Geophysical Research Published on: 09/2005 YEAR: 2005 DOI: 10.1029/2004JA010882 
2004 
Quantification of relativistic electron microburst losses during the GEM storms Bursty precipitation of relativistic electrons has been implicated as a major loss process during magnetic storms. One type of precipitation, microbursts, appears to contain enough electrons to empty the prestorm outer radiation belt in approximately a day. During storms that result in high fluxes of trapped relativistic electrons, microbursts continue for several days into the recovery phase, when trapped fluxes are dramatically increasing. The present study shows that this apparent inconsistency is resolved by observations ... O\textquoterightBrien, T.; Looper, M.; Blake, J.; Published by: Geophysical Research Letters Published on: 02/2004 YEAR: 2004 DOI: 10.1029/2003GL018621 
2003 
Evaluation of quasilinear diffusion coefficients for EMIC waves in a multispecies plasma Quasilinear velocityspace diffusion coefficients due to Lmode electromagnetic ion cyclotron (EMIC) waves are considered in a multispecies plasma. It is shown, with slight approximations to exact cold plasma theory, that within EMIC pass bands the index of refraction is a monotonically increasing function of frequency. Analytical criteria are then derived which identify ranges of latitude, wavenormal angle, and resonance number consistent with resonance in a prescribed wave population. This leads to computational technique ... Published by: Journal of Geophysical Research Published on: 06/2003 YEAR: 2003 DOI: 10.1029/2002JA009792 
Electromagnetic ion cyclotron (EMIC) waves which propagate at frequencies below the proton gyrofrequency can undergo cyclotron resonant interactions with relativistic electrons in the outer radiation belt and cause pitchangle scattering and electron loss to the atmosphere. Typical stormtime wave amplitudes of 1\textendash10 nT cause strong diffusion scattering which may lead to significant relativistic electron loss at energies above the minimum energy for resonance, Emin. A statistical analysis of over 800 EMIC wave event ... Published by: Journal of Geophysical Research Published on: 06/2003 YEAR: 2003 DOI: 10.1029/2002JA009700 
1] Resonant interactions with whistlermode chorus waves provide an important process for electron loss and acceleration during storm times. We demonstrate that wave propagation significantly affects the electron scattering rates. We show that stormtime chorus waves outside the plasmapause can scatter equatorial electrons <=60 keV into the loss cone and accelerate trapped electrons up to \~ MeV energies at large pitchangles. Using ray tracing to map the waves to higher latitudes, we show that the decrease in the ratio betwe ... Published by: Geophysical Research Letters Published on: 05/2003 YEAR: 2003 DOI: 10.1029/2003GL016973 
[1] During magnetic storms, relativistic electrons execute nearly circular orbits about the Earth and traverse a spatially confined zone within the duskside plasmapause where electromagnetic ion cyclotron (EMIC) waves are preferentially excited. We examine the mechanism of electron pitchangle diffusion by gyroresonant interaction with EMIC waves as a cause of relativistic electron precipitation loss from the outer radiation belt. Detailed calculations are carried out of electron cyclotron resonant pitchangle diffusion coef ... Published by: Journal of Geophysical Research Published on: 04/2003 YEAR: 2003 DOI: 10.1029/2002JA009489 
2002 
Xray observations of MeV electron precipitation with a balloonborne germanium spectrometer The highresolution germanium detector aboard the MAXIS (MeV Auroral Xray Imaging and Spectroscopy) balloon payload detected nine Xray bursts with significant flux extending above 0.5 MeV during an 18 day flight over Antarctica. These minutestohourslong events are characterized by an extremely flat spectrum (\~E2) similar to the first MeV event discovered in 1996, indicating that the bulk of parent precipitating electrons is at relativistic energies. The MeV bursts were detected between magnetic latitudes 58\textdegree ... Published by: Geophysical Research Letters Published on: 12/2002 YEAR: 2002 DOI: 10.1029/2002GL015922 
1998 
Electron scattering loss in Earth\textquoterights inner magnetosphere 1. Dominant physical processes Pitch angle diffusion rates due to Coulomb collisions and resonant interactions with plasmaspheric hiss, lightninginduced whistlers and anthropogenic VLF transmissions are computed for inner magnetospheric electrons. The bounceaveraged, quasilinear pitch angle diffusion coefficients are input into a pure pitch angle diffusion equation to obtain L and energy dependent equilibrium distribution functions and precipitation lifetimes. The relative effects of each scattering mechanism are considered as a function of electron en ... Published by: Journal of Geophysical Research Published on: 02/1998 YEAR: 1998 DOI: 10.1029/97JA02919 
1973 
Equilibrium Structure of Radiation Belt Electrons The detailed quiet time structure of energetic electrons in the earth\textquoterights radiation belts is explained on the basis of a balance between pitch angle scattering loss and inward radial diffusion from an average outer zone source. Losses are attributed to a combination of classical Coulomb scattering at low L and whistler mode turbulent pitch angle diffusion throughout the outer plasmasphere. Radial diffusion is driven by substorm associated fluctuations of the magnetospheric convection electric field. Lyons, Lawrence; Thorne, Richard; Published by: Journal of Geophysical Research Published on: 05/1973 YEAR: 1973 DOI: 10.1029/JA078i013p02142 
1972 
Parasitic Pitch Angle Diffusion of Radiation Belt Particles by Ion Cyclotron Waves The resonant pitch angle scattering of protons and electrons by ion cyclotron turbulence is investigated. The analysis is analogous to that recently performed for electron interactions with whistler mode waves. The role played by the intense band of ion cyclotron waves, predicted to be generated just within the plasmapause during the decay of the magnetospheric ring current, is evaluated in detail. Loss rates resulting from parasitic interactions with this turbulence are determined for energetic protons and relativistic elec ... Lyons, Lawrence; Thorne, Richard; Published by: Journal of Geophysical Research Published on: 10/1972 YEAR: 1972 DOI: 10.1029/JA077i028p05608 
1966 
Velocity Space Diffusion from Weak Plasma Turbulence in a Magnetic Field The quasilinear velocity space diffusion is considered for waves of any oscillation branch propagating at an arbitrary angle to a uniform magnetic field in a spatially uniform plasma. The spaceaveraged distribution function is assumed to change slowly compared to a gyroperiod and characteristic times of the wave motion. Nonlinear mode coupling is neglected. An Hlike theorem shows that both resonant and nonresonant quasilinear diffusion force the particle distributions towards marginal stablity. Creation of the marginally ... Published by: Physics of Fluids Published on: 12/1966 YEAR: 1966 DOI: 10.1063/1.1761629 
Limit on Stably Trapped Particle Fluxes Whistler mode noise leads to electron pitch angle diffusion. Similarly, ion cyclotron noise couples to ions. This diffusion results in particle precipitation into the ionosphere and creates a pitch angle distributon of trapped particles that is unstable to further wave growth. Since excessive wave growth leads to rapid diffusion and particle loss, the requirement that the growth rate be limited to the rate at which wave energy is depleted by wave propagation permits an estimate of an upper limit to the trapped equatorial par ... Published by: Journal Geophysical Research Published on: 01/1966 YEAR: 1966 DOI: 10.1029/JZ071i001p00001 
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