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Van Allen Probes Bibliography is from August 2012 through September 2021
Found 9 entries in the Bibliography.
Showing entries from 1 through 9
ULF Wave Driven Radial Diffusion During Geomagnetic Storms: A statistical analysis of Van Allen Probes observations
Abstract The impact of radial diffusion in storm time radiation belt dynamics is well-debated. In this study we quantify the changes and variability in radial diffusion coefficients during geomagnetic storms. A statistical analysis of Van Allen Probes data (2012 − 2019) is conducted to obtain measurements of the magnetic and electric power spectral densities for Ultra Low Frequency (ULF) waves, and corresponding radial diffusion coefficients. The results show global wave power enhancements occur during the storm main phase ...
Sandhu, J.; Rae, I.; Wygant, J.; Breneman, A.; Tian, S.; Watt, C.; Horne, R.; Ozeke, L.; Georgiou, M.; Walach, M.-T.;
Published by: Journal of Geophysical Research: Space Physics Published on: 03/2021
YEAR: 2021   DOI: https://doi.org/10.1029/2020JA029024
ULF waves; radial diffusion; outer radiation belt; Van Allen Probes; Geomagnetic storms
Determining the Temporal and Spatial Coherence of Plasmaspheric Hiss Waves in the Magnetosphere
Abstract Plasmaspheric hiss is one of the most important plasma waves in the Earth s magnetosphere to contribute to radiation belt dynamics by pitch-angle scattering energetic electrons via wave-particle interactions. There is growing evidence that the temporal and spatial variability of wave-particle interactions are important factors in the construction of diffusion-based models of the radiation belts. Hiss amplitudes are thought to be coherent across large distances and on long timescales inside the plasmapause, which mea ...
Zhang, Shuai; Rae, Jonathan; Watt, Clare; Degeling, Alexander; Tian, Anmin; Shi, Quanqi; Shen, Xiao-Chen; Smith, Andy; Wang, Mengmeng;
Published by: Journal of Geophysical Research: Space Physics Published on: 02/2021
YEAR: 2021   DOI: https://doi.org/10.1029/2020JA028635
The Implications of Temporal Variability in Wave-Particle Interactions in Earth s Radiation Belts
Changes in electron flux in Earth s outer radiation belt can be modeled using a diffusion-based framework. Diffusion coefficients D for such models are often constructed from statistical averages of observed inputs. Here, we use stochastic parameterization to investigate the consequences of temporal variability in D. Variability time scales are constrained using Van Allen Probe observations. Results from stochastic parameterization experiments are compared with experiments using D constructed from averaged inputs and an aver ...
Watt, C.; Allison, H.; Thompson, R.; Bentley, S.; Meredith, N.; Glauert, S.; Horne, R.; Rae, I.;
Published by: Geophysical Research Letters Published on: 12/2020
YEAR: 2020   DOI: https://doi.org/10.1029/2020GL089962
probabilistic methods; stochastic parameterization; Van Allen Probes
A New Approach to Constructing Models of Electron Diffusion by EMIC Waves in the Radiation Belts
Electromagnetic ion cyclotron (EMIC) waves play an important role in relativistic electron losses in the radiation belts through diffusion via resonant wave-particle interactions. We present a new approach for calculating bounce and drift-averaged EMIC electron diffusion coefficients. We calculate bounce-averaged diffusion coefficients, using quasi-linear theory, for each individual Combined Release and Radiation Effects Satellite (CRRES) EMIC wave observation using fitted wave properties, the plasma density and the backgrou ...
Ross, J.; Glauert, S.; Horne, R.; Watt, C.; Meredith, N.; Woodfield, E.;
Published by: Geophysical Research Letters Published on: 10/2020
YEAR: 2020   DOI: https://doi.org/10.1029/2020GL088976
Radiation belts; EMIC waves; electron diffusion; Van Allen Probes
Variability of Quasilinear Diffusion Coefficients for Plasmaspheric Hiss
In the outer radiation belt, the acceleration and loss of high-energy electrons is largely controlled by wave-particle interactions. Quasilinear diffusion coefficients are an efficient way to capture the small-scale physics of wave-particle interactions due to magnetospheric wave modes such as plasmaspheric hiss. The strength of quasilinear diffusion coefficients as a function of energy and pitch angle depends on both wave parameters and plasma parameters such as ambient magnetic field strength, plasma number density, and co ...
Watt, C.; Allison, H.; Meredith, N.; Thompson, R.; Bentley, S.; Rae, I.; Glauert, S.; Horne, R.;
Published by: Journal of Geophysical Research: Space Physics Published on: 10/2019
YEAR: 2019   DOI: 10.1029/2018JA026401
empirical; Magnetosphere; parameterization; stochastic; Van Allen Probes; wave-particle interactions
Determining the mode, frequency, and azimuthal wave number of ULF waves during a HSS and moderate geomagnetic storm
Ultra-low frequency (ULF) waves play a fundamental role in the dynamics of the inner-magnetosphere and outer radiation belt during geomagnetic storms. Broadband ULF wave power can transport energetic electrons via radial diffusion and discrete ULF wave power can energize electrons through a resonant interaction. Using observations from the Magnetospheric Multiscale (MMS) mission, we characterize the evolution of ULF waves during a high-speed solar wind stream (HSS) and moderate geomagnetic storm while there is an enhancement ...
Murphy, Kyle; Inglis, Andrew; Sibeck, David; Rae, Jonathan; Watt, Clare; Silveira, Marcos; Plaschke, Ferdinand; Claudepierre, Seth; Nakamura, Rumi;
Published by: Journal of Geophysical Research: Space Physics Published on: 05/2018
YEAR: 2018   DOI: 10.1029/2017JA024877
azimuthal wave number; Geomagnetic storms; mode structure; Radiation belts; ULF waves; Van Allen Probes
The global statistical response of the outer radiation belt during geomagnetic storms
Using the total radiation belt electron content calculated from Van Allen Probe phase space density (PSD), the time-dependent and global response of the outer radiation belt during storms is statistically studied. Using PSD reduces the impacts of adiabatic changes in the main phase, allowing a separation of adiabatic and non-adiabatic effects, and revealing a clear modality and repeatable sequence of events in storm-time radiation belt electron dynamics. This sequence exhibits an important first adiabatic invariant (μ) depe ...
Murphy, Kyle; Watt, C.; Mann, Ian; Rae, Jonathan; Sibeck, David; Boyd, A.; Forsyth, C.; Turner, D.; Claudepierre, S.; Baker, D.; Spence, H.; Reeves, G.; Blake, J.; Fennell, J.;
Published by: Geophysical Research Letters Published on: 04/2018
YEAR: 2018   DOI: 10.1002/2017GL076674
Geomagnetic storms; magnetospheric dynamics; Radiation belts; Solar Wind-Magnetosphere Coupling; statistical analysis; Van Allen Probes
What effect do substorms have on the content of the radiation belts?
Substorms are fundamental and dynamic processes in the magnetosphere, converting captured solar wind magnetic energy into plasma energy. These substorms have been suggested to be a key driver of energetic electron enhancements in the outer radiation belts. Substorms inject a keV \textquotedblleftseed\textquotedblright population into the inner magnetosphere which is subsequently energized through wave-particle interactions up to relativistic energies; however, the extent to which substorms enhance the radiation belts, either ...
Forsyth, C.; Rae, I.; Murphy, K.; Freeman, M.; Huang, C.-L.; Spence, H.; Boyd, A.; Coxon, J.; Jackman, C.; Kalmoni, N.; Watt, C.;
Published by: Journal of Geophysical Research: Space Physics Published on: 06/2016
YEAR: 2016   DOI: 10.1002/2016JA022620
Using the cold plasma dispersion relation and whistler-mode waves to quantify the antenna sheath impedance of the Van Allen Probes EFW instrument
Cold plasma theory and parallel wave propagation are often assumed when approximating the whistler mode magnetic field wave power from electric field observations. The current study is the first to include the wave normal angle from the Electric and Magnetic Field Instrument Suite and Integrated Science package on board the Van Allen Probes in the conversion factor, thus allowing for the accuracy of these assumptions to be quantified. Results indicate that removing the assumption of parallel propagation does not significantl ...
Hartley, D.; Kletzing, C.; Kurth, W.; Bounds, S.; Averkamp, T.; Hospodarsky, G.; Wygant, J.; Bonnell, J.; ik, O.; Watt, C.;
Published by: Journal of Geophysical Research: Space Physics Published on: 05/2016
YEAR: 2016   DOI: 10.1002/2016JA022501
EFW; EMFISIS; Plasmaspheric Hiss; sheath impedance; Van Allen Probes; whistler mode chorus