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Van Allen Probes Bibliography is from August 2012 through September 2021 Notice:
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Found 57 entries in the Bibliography.
Showing entries from 1 through 50
| 2021 |
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Abstract Geomagnetic substorms are major energy transfer events where energy stored in the Earths magnetotail is released into the ionosphere. Substorm phenomena, including auroral activities, earthward Poynting flux, magnetic field dipolarization, etc, have been extensively studied. However, the complex interplay among them is not fully understood. In a fortuitous event on June 07, 2013, the twin Van Allen Probes (separated by 0.4 hour in local time) observed bursts of earthward Alfvenic Poynting flux in the vicinity of the ... Tian, S.; Colpitts, C.; Wygant, J.; Cattell, C.; Ferradas, C.; Igl, A.; Larsen, B.; Reeves, G.; Donovan, E.; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA029019 Poynting flux; auroral physics; discrete arc; Dipolarization; Alfven waves; Van Allen Probes |
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Abstract We present, for the first time, a plasmaspheric hiss event observed by the Van Allen probes in response to two successive interplanetary shocks occurring within an interval of ∼2 hours on December 19, 2015. The first shock arrived at 16:16 UT and caused disappearance of hiss for ∼30 minutes. Combined effect of plasmapause crossing, significant Landau damping by suprathermal electrons and their gradual removal by magnetospheric compression led to the disappearance of hiss. Calculation of electron phase space dens ... Chakraborty, S.; Chakrabarty, D.; Reeves, G.; Baker, D.; Claudepierre, S.; Breneman, A.; Hartley, D.; Larsen, B.; Published by: Journal of Geophysical Research: Space Physics Published on: 03/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA028873 Plasmaspheric Hiss; Van Allen Probe; Interplanetary shocks; substorms; Whistlers; ULF waves; Van Allen Probes |
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RBSP-ECT Combined Pitch Angle Resolved Electron Flux Data Product Abstract We describe a new data product combining pitch angle resolved electron flux measurements from the Radiation Belt Storm Probes (RBSP) Energetic Particle Composition and Thermal Plasma (ECT) suite on the National Aeronautics and Space Administration s Van Allen Probes. We describe the methodology used to combine each of the data sets and produce a consistent set of pitch-angle-resolved spectra for the entire Van Allen Probes mission. Three-minute-averaged flux spectra are provided spanning energies from 15 eV up to 20 ... Boyd, A.J.; Spence, H.E.; Reeves, G.D.; Funsten, H.O; Skoug, R.K.; Larsen, B.A.; Blake, J.B.; Fennell, J.F.; Claudepierre, S.G.; Baker, D.N.; Kanekal, S.K.; Jaynes, A.N.; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA028637 |
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Abstract We present a statistical study of density cavities observed in the inner magnetosphere by the Van Allen Probes during four one-month periods: February 2013, July 2013, January 2014 and June 2014. These periods were chosen to allow the survey of all magnetic local times. We find that density cavities are a recurrent feature of the density profiles of in situ measurements in the inner magnetosphere. We further investigate the correlation between the density cavities and the enhancement of fluxes of warm ions with ener ... Ferradas, C.; Boardsen, S.; Fok, M.-C.; Buzulukova, N.; Reeves, G.; Larsen, B.; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA028326 Magnetosphere: inner; plasmasphere; magnetospheric configuration and dynamics; plasma waves and instabilities; plasma sheet; density cavity; cold ion heating; cold ions; warm Plasma cloak; Van Allen Probes |
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Bayesian Model for HOPE Mass Spectrometers on Van Allen Probes Abstract Space instruments rely heavily on modeling to predict and understand the instrument response, enabling a determination of the capabilities and resolution. The Bayesian approach provides a framework to incorporate prior knowledge and propagate uncertainty to predict the instrument response. We present an empirical Bayes model for the end-to-end performance of the Helium, Oxygen, Proton, and Electron (HOPE) mass spectrometers aboard the Van Allen Probes mission. In this model, we use a combination of external modeling ... Vira, A.; Larsen, B.; Skoug, R.; Fernandes, P.; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA028862 |
| 2020 |
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Using seven years of data from the HOPE instrument on the Van Allen Probes, equatorial pitch angle distributions (PADs) of 1 – 50 keV electrons in Earth s inner magnetosphere are investigated statistically. An empirical model of electron equatorial PADs as a function of radial distance, magnetic local time, geomagnetic activity, and electron energy is constructed using the method of Legendre polynomial fitting. Model results show that most equatorial PADs of 1 – 10s of keV electrons in Earth s inner magnetosphere are pan ... Zhao, H.; Friedel, R.; Chen, Y.; Baker, D.; Li, X.; Malaspina, D.; Larsen, B.; Skoug, R.; Funsten, H.; Reeves, G.; Boyd, A.; Published by: Journal of Geophysical Research: Space Physics Published on: 12/2020 YEAR: 2020 DOI: https://doi.org/10.1029/2020JA028322 Pitch angle distribution; energetic electrons; Earth s inner magnetosphere; Anisotropy; Chorus wave; statistical analysis; Van Allen Probes |
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Defining Radiation Belt Enhancement Events Based on Probability Distributions We present a methodology to define moderate, strong, and intense space weather events based on probability distributions. We have illustrated this methodology using a long-duration, uniform data set of 1.8–3.5 MeV electron fluxes from multiple LANL geosynchronous satellite instruments, but a strength of this methodology is that it can be applied uniformly to heterogeneous data sets. It allows quantitative comparison of data sets with different energies, units, orbits, and so forth. The methodology identifies a range of ti ... Reeves, Geoffrey; Vandegriff, Elizabeth; Niehof, Jonathan; Morley, Steven; Cunningham, Gregory; Henderson, Michael; Larsen, Brian; Published by: Space Weather Published on: 06/2020 YEAR: 2020 DOI: https://doi.org/10.1029/2020SW002528 Radiation belts; methods; geosynchronous; energetic particles; hazards; Solar Cycle; Van Allen Probes |
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Global ENA Imaging and In Situ Observations of Substorm Dipolarization on 10 August 2016 Abstract This paper presents the first combined use of data from Magnetospheric Multiscale (MMS), Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS), and Van Allen Probes (RBSP) to study the 10 August 2016 magnetic dipolarization. We report the first correlation of MMS tail observations with TWINS energetic neutral atom (ENA) images of the ring current (RC). We analyze 15-min, 1° TWINS 2 images in 1–50 keV energy bins. To characterize the high-altitude RC we extract peak ENA flux from L= 2.5 to 5 in the postmid ... Goldstein, J.; Valek, P.; McComas, D.; Redfern, J.; Spence, H.; Skoug, R.; Larsen, B.; Reeves, G.; Nakamura, R.; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2020 YEAR: 2020 DOI: 10.1029/2019JA027733 substorm dipolarization; cross-scale physics; imaging; multipoint in situ; ring current; Van Allen Probes |
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Global ENA Imaging and In Situ Observations of Substorm Dipolarization on 10 August 2016 This paper presents the first combined use of data from Magnetospheric Multiscale (MMS), Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS), and Van Allen Probes (RBSP) to study the 10 August 2016 magnetic dipolarization. We report the first correlation of MMS tail observations with TWINS energetic neutral atom (ENA) images of the ring current (RC). We analyze 15-min, 1° TWINS 2 images in 1–50 keV energy bins. To characterize the high-altitude RC we extract peak ENA flux from L= 2.5 to 5 in the postmidnight sec ... Goldstein, J.; Valek, P.; McComas, D.; Redfern, J.; Spence, H.; Skoug, R.; Larsen, B.; Reeves, G.; Nakamura, R.; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2020 YEAR: 2020 DOI: https://doi.org/10.1029/2019JA027733 substorm dipolarization; cross-scale physics; imaging; multipoint in situ; ring current |
| 2019 |
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The magnetospheric driver of strong thermal emission velocity enhancement (STEVE) is investigated using conjugate observations when Van Allen Probes\textquoteright footprint directly crossed both STEVE and stable red aurora (SAR) arc. In the ionosphere, STEVE is associated with subauroral ion drift features, including electron temperature peak, density gradient, and westward ion flow. The SAR arc at lower latitudes corresponds to regions inside the plasmapause with isotropic plasma heating, which causes redline-only SAR emis ... Chu, Xiangning; Malaspina, David; Gallardo-Lacourt, Bea; Liang, Jun; Andersson, Laila; Ma, Qianli; Artemyev, Anton; Liu, Jiang; Ergun, Robert; Thaller, Scott; Akbari, Hassanali; Zhao, Hong; Larsen, Brian; Reeves, Geoffrey; Wygant, John; Breneman, Aaron; Tian, Sheng; Connors, Martin; Donovan, Eric; Archer, William; MacDonald, Elizabeth; Published by: Geophysical Research Letters Published on: 11/2019 YEAR: 2019 DOI: 10.1029/2019GL082789 aurora; kinetic Alfven wave; Plasmapause; STEVE; subauroral ion drift; table red auroral arc; Van Allen Probes |
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RBSP-ECT Combined Spin-Averaged Electron Flux Data Product We describe a new data product combining the spin-averaged electron flux measurements from the Radiation Belt Storm Probes (RBSP) Energetic Particle Composition and Thermal Plasma (ECT) suite on the National Aeronautics and Space Administration\textquoterights Van Allen Probes. We describe the methodology used to combine each of the data sets and produce a consistent set of spectra for September 2013 to the present. Three-minute-averaged flux spectra are provided spanning energies from 15 eV up to 20 MeV. This new data produ ... Boyd, A.; Reeves, G.; Spence, H.; Funsten, H.; Larsen, B.; Skoug, R.; Blake, J.; Fennell, J.; Claudepierre, S.; Baker, D.; Kanekal, S.; Jaynes, A.; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2019 YEAR: 2019 DOI: 10.1029/2019JA026733 |
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Electrons with energies in the keV range play an important role in the dynamics of the inner magnetosphere. Therefore, accurately modeling electron fluxes in this region is of great interest. However, these calculations constitute a challenging task since the lifetimes of electrons that are available have limitations. In this study, we simulate electron fluxes in the energy range of 20 eV to 100 keV to assess how well different electron loss models can account for the observed electron fluxes during the Geospace Environment ... Ferradas, C.; Jordanova, V.; Reeves, G.; Larsen, B.; Published by: Journal of Geophysical Research: Space Physics Published on: 09/2019 YEAR: 2019 DOI: 10.1029/2019JA026649 electron lifetime; electron loss; numerical modeling; pitch angle scattering; Van Allen Probes; Weimer electric field model |
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Temperature Dependence of Plasmaspheric Ion Composition We analyze a database of Dynamics Explorer-1 (DE-1) Retarding Ion Mass Spectrometer densities and temperatures to yield the first explicit measure of how cold ion concentration depends on temperature. We find that cold H+ and He+ concentrations have very weak dependence on temperature, but cold O+ ion concentration increases steeply as these ions become warmer. We demonstrate how this result can aid in analyzing composition data from other satellites without spacecraft potential mitigation, by applying the result to an examp ... Goldstein, J.; Gallagher, D.; Craven, P.; Comfort, R.; Genestreti, K.; Mouikis, C.; Spence, H.; Kurth, W.; Wygant, J.; Skoug, R.; Larsen, B.; Reeves, G.; De Pascuale, S.; Published by: Journal of Geophysical Research: Space Physics Published on: 07/2019 YEAR: 2019 DOI: 10.1029/2019JA026822 composition; plasmasphere: ion; temperature; Van Allen Probes |
| 2018 |
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Plasma anisotropies and currents in the near-Earth plasma sheet and inner magnetosphere The region occupying radial distances of \~3 - 9 Earth radii (RE) in the night side, includes the near-Earth plasma sheet with stretched magnetic field lines and the inner magnetosphere with strong dipolar magnetic field. In this region, the plasma flow energy, which was injected into the inner magnetosphere from the magnetotail, is converted to particle heating and electromagnetic wave generation. These important processes are controlled by plasma anisotropies, which are the focus of this study. Using measurements of THEMIS ... Artemyev, A.; Zhang, X.-J.; Angelopoulos, V.; Runov, A.; Spence, H.; Larsen, B.; Published by: Journal of Geophysical Research: Space Physics Published on: 06/2018 YEAR: 2018 DOI: 10.1029/2018JA025232 injections; inner magnetosphere; plasma currents; plasma sheet; Van Allen Probes |
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We perform a statistical study calculating electromagnetic ion cyclotron (EMIC) wave amplitudes based off in situ plasma measurements taken by the Van Allen Probes\textquoteright (1.1\textendash5.8 Re) Helium, Oxygen, Proton, Electron (HOPE) instrument. Calculated wave amplitudes are compared to EMIC waves observed by the Electric and Magnetic Field Instrument Suite and Integrated Science on board the Van Allen Probes during the same period. The survey covers a 22-month period (1 November 2012 to 31 August 2014), a full Van ... Saikin, A.A.; Jordanova, V.K.; Zhang, J.C.; Smith, C.W.; Spence, H.E.; Larsen, B.A.; Reeves, G.D.; Torbert, R.B.; Kletzing, C.A.; Zhelavskaya, I.S.; Shprits, Y.Y.; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 02/2018 YEAR: 2018 DOI: 10.1016/j.jastp.2018.01.024 EMIC waves Van Allen Probes Linear theory Wave generation; Van Allen Probes |
| 2017 |
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Temporal evolution of ion spectral structures during a geomagnetic storm: Observations and modeling Using the Van Allen Probes/Helium, Oxygen, Proton, and Electron (HOPE) mass spectrometer, we perform a case study of the temporal evolution of ion spectral structures observed in the energy range of 1-~50 keV throughout the geomagnetic storm of 2 October 2013. The ion spectral features are observed near the inner edge of the plasma sheet and are signatures of fresh transport from the plasma sheet into the inner magnetosphere. We find that the characteristics of the ion structures are determined by the intensity of the convec ... Ferradas, C.; Zhang, J.-C.; Spence, H.; Kistler, L.; Larsen, B.; Reeves, G.; Skoug, R.; Funsten, H.; Published by: Journal of Geophysical Research: Space Physics Published on: 12/2017 YEAR: 2017 DOI: 10.1002/2017JA024702 Geomagnetic storm; ion injection; ion nose structure; numerical modeling; Van Allen Probes; Weimer electric field model |
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The Evolution of the Plasma Sheet Ion Composition: Storms and Recoveries The ion plasma sheet (~few hundred eV to ~few 10s keV) is usually dominated by H+ ions. Here, changes in ion composition within the plasma sheet are explored both during individual events, and statistically during 54 calm-to-storm events and during 21 active-to-calm events. Ion composition data from the HOPE (Helium, Oxygen, Proton, Electron) instruments onboard Van Allen Probes satellites provide exceptional spatial and temporal resolution of the H+, O+, and He+ ion fluxes in the plasma sheet. H+ shown to be the dominant io ... Denton, M.; Thomsen, M.; Reeves, G.; Larsen, B.; Henderson, M.; Jordanova, V.; Fernandes, P.; Friedel, R.; Skoug, R.; Funsten, H.; MacDonald, E.; Spence, H.; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2017 YEAR: 2017 DOI: 10.1002/2017JA024475 |
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The Warm Plasma Composition in the Inner Magnetosphere during 2012-2015 Ionospheric heavy ions play an important role in the dynamics of Earth\textquoterights magnetosphere. The greater mass and gyro radius of ionospheric oxygen differentiates its behavior from protons at the same energies. Oxygen may have an impact on tail reconnection processes, and it can at least temporarily dominate the energy content of the ring current during geomagnetic storms. At sub-keV energies, multi-species ion populations in the inner magnetosphere form the warm plasma cloak, occupying the energy range between the ... Jahn, J.-M.; Goldstein, J.; Reeves, G.; Fernandes, P.; Skoug, R.; Larsen, B.; Spence, H.; Published by: Journal of Geophysical Research: Space Physics Published on: 09/2017 YEAR: 2017 DOI: 10.1002/2017JA024183 geomagnetic activity; inner magnetosphere; plasma composition; plasma density; statistics; Van Allen Probes |
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The plasma environment inside geostationary orbit: A Van Allen Probes HOPE survey The two full precessions in local time completed by the Van Allen Probes enable global specification of the near-equatorial inner magnetosphere plasma environment. Observations by the Helium-Oxygen-Proton-Electron (HOPE) mass spectrometers provide detailed insight into the global spatial distribution of electrons, H+, He+, and O+. Near-equatorial omnidirectional fluxes and abundance ratios at energies 0.1\textendash30 keV are presented for 2 <= L <= 6 as a function of L shell, magnetic local time (MLT), and geomagnetic activ ... Fernandes, Philip; Larsen, Brian; Thomsen, Michelle; Skoug, Ruth; Reeves, Geoffrey; Denton, Michael; Friedel, Reinhard; Funsten, Herbert; Goldstein, Jerry; Henderson, Michael; Jahn, örg-Micha; MacDonald, Elizabeth; Olson, David; Published by: Journal of Geophysical Research: Space Physics Published on: 08/2017 YEAR: 2017 DOI: 10.1002/2017JA024160 inner magnetosphere; magnetospheric composition; plasma access; plasma convection; UBK modeling; Van Allen Probes |
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Roles of hot electrons in generating upper-hybrid waves in the earth\textquoterights radiation belt Electrostatic fluctuations near upper-hybrid frequency, which are sometimes accompanied by multiple-harmonic electron cyclotron frequency bands above and below the upper-hybrid frequency, are common occurrences in the Earth\textquoterights radiation belt, as revealed through the twin Van Allen Probe spacecrafts. It is customary to use the upper-hybrid emissions for estimating the background electron density, which in turn can be used to determine the plasmapause locations, but the role of hot electrons in generating such flu ... Hwang, J.; Shin, D.; Yoon, P.; Kurth, W.; Larsen, B.; Reeves, G.; Lee, D; Published by: Physics of Plasmas Published on: 06/2017 YEAR: 2017 DOI: 10.1063/1.4984249 Hot carriers; Magnetized plasmas; Radiation belts; Singing; Van Allen Probes; Whistler waves |
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Second harmonic poloidal waves observed by Van Allen Probes in the dusk-midnight sector This paper presents observations of ultralow-frequency (ULF) waves from Van Allen Probes. The event that generated the ULF waves occurred 2 days after a minor geomagnetic storm during a geomagnetically quiet time. Narrowband pulsations with a frequency of about 7 mHz with moderate amplitudes were registered in the premidnight sector when Probe A was passing through an enhanced density region near geosynchronous orbit. Probe B, which passed through the region earlier, did not detect the narrowband pulsations but only broadban ... Min, Kyungguk; Takahashi, Kazue; Ukhorskiy, Aleksandr; Manweiler, Jerry; Spence, Harlan; Singer, Howard; Claudepierre, Seth; Larsen, Brian; Soto-Chavez, Rualdo; Cohen, Ross; Published by: Journal of Geophysical Research: Space Physics Published on: 03/2017 YEAR: 2017 DOI: 10.1002/2016JA023770 drift-bounce resonance; high m ULF waves; Second harmonic poloidal mode; Van Allen Probes |
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Accurate knowledge of the plasma fluxes in the inner magnetosphere is essential for both scientific and programmatic applications. Knowledge of the low-energy electrons (approximately tens to hundreds of eV) in the inner magnetosphere is particularly important since these electrons are acted upon by various physical processes, accelerating the electrons to higher energies, and also causing their loss. However, measurements of low-energy electrons are challenging, and as a result, this population has been somewhat neglected p ... Denton, M.; Reeves, G.; Larsen, B.; Friedel, R.; Thomsen, M.; Fernandes, P.; Skoug, R.; Funsten, H.; Sarno-Smith, L.; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2017 YEAR: 2017 DOI: 10.1002/2016JA023648 |
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Second harmonic poloidal waves observed by Van Allen Probes in the dusk-midnight sector This paper presents observations of ultra-low frequency (ULF) waves from Van Allen Probes. The event that generated the ULF waves occurred two days after a minor geomagnetic storm during a geomagnetically quiet time. Narrowband pulsations with a frequency of about 7 mHz with moderate amplitudes were registered in the pre-midnight sector when Probe A was passing through an enhanced density region near geosynchronous orbit. Probe B, which passed through the region earlier, did not detect the narrowband pulsations but only broa ... Min, Kyungguk; Takahashi, Kazue; Ukhorskiy, Aleksandr; Manweiler, Jerry; Spence, Harlan; Singer, Howard; Claudepierre, Seth; Larsen, Brian; Soto-Chavez, Rualdo; Cohen, Ross; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2017 YEAR: 2017 DOI: 10.1002/2016JA023770 drift-bounce resonance; high m ULF waves; Second harmonic poloidal mode; Van Allen Probes |
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Accurate knowledge of the plasma fluxes in the inner magnetosphere is essential for both scientific and programmatic applications. Knowledge of the low-energy electrons (approximately tens to hundreds of eV) in the inner magnetosphere is particularly important since these electrons are acted upon by various physical processes, accelerating the electrons to higher energies, and also causing their loss. However, measurements of low-energy electrons are challenging, and as a result, this population has been somewhat neglected p ... Denton, M.; Reeves, G.; Larsen, B.; Friedel, R.; Thomsen, M.; Fernandes, P.; Skoug, R.; Funsten, H.; Sarno-Smith, L.; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2017 YEAR: 2017 DOI: 10.1002/2016JA023648 |
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Temperature of the plasmasphere from Van Allen Probes HOPE Genestreti, K.; Goldstein, J.; Corley, G.; Farner, W.; Kistler, L.; Larsen, B.; Mouikis, C.; Ramnarace, C.; Skoug, R.; Turner, N.; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2017 YEAR: 2017 DOI: 10.1002/2016JA023047 |
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Temperature of the plasmasphere from Van Allen Probes HOPE We introduce two novel techniques for estimating temperatures of very low energy space plasmas using, primarily, in situ data from an electrostatic analyzer mounted on a charged and moving spacecraft. The techniques are used to estimate proton temperatures during intervals where the bulk of the ion plasma is well below the energy bandpass of the analyzer. Both techniques assume that the plasma may be described by a one-dimensional math formula drifting Maxwellian and that the potential field and motion of the spacecraft may ... Genestreti, K.; Goldstein, J.; Corley, G.; Farner, W.; Kistler, L.; Larsen, B.; Mouikis, C.; Ramnarace, C.; Skoug, R.; Turner, N.; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2017 YEAR: 2017 DOI: 10.1002/jgra.v122.110.1002/2016JA023047 |
| 2016 |
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We present a case study of the H+, He+, and O+ multiple-nose structures observed by the Helium, Oxygen, Proton, and Electron instrument on board Van Allen Probe A over one complete orbit on 28 September 2013. Nose structures are observed near the inner edge of the plasma sheet and constitute the signatures of ion drift in the highly dynamic environment of the inner magnetosphere. We find that the multiple noses are intrinsically associated with variations in the solar wind. Backward ion drift path tracings show new details o ... Ferradas, C.; Zhang, J.-C.; Spence, H.; Kistler, L.; Larsen, B.; Reeves, G.; Skoug, R.; Funsten, H.; Published by: Geophysical Research Letters Published on: 11/2016 YEAR: 2016 DOI: 10.1002/2016GL071359 drift path; ion injection; ion nose structure; numerical modeling; Van Allen Probes; Weimer electric field model |
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Ion nose spectral structures observed by the Van Allen Probes We present a statistical study of nose-like structures observed in energetic hydrogen, helium, and oxygen ions near the inner edge of the plasma sheet. Nose structures are spectral features named after the characteristic shapes of energy bands or gaps in the energy-time spectrograms of in situ measured ion fluxes. Using 22 months of observations from the Helium Oxygen Proton Electron (HOPE) instrument onboard Van Allen Probe A, we determine the number of noses observed, and the minimum L-shell reached and energy of each nose ... Ferradas, C.; Zhang, J.-C.; Spence, H.; Kistler, L.; Larsen, B.; Reeves, G.; Skoug, R.; Funsten, H.; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2016 YEAR: 2016 DOI: 10.1002/2016JA022942 inner magnetosphere; ion injection; Ion structure; plasma sheet; ring current; Van Allen Probes |
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Ring Current Pressure Estimation with RAM-SCB using Data Assimilation and Van Allen Probe Flux Data Capturing and subsequently modeling the influence of tail plasma injections on the inner magnetosphere is important for understanding the formation and evolution of the ring current. In this study, the ring current distribution is estimated with the Ring Current-Atmosphere Interactions Model with Self-Consistent Magnetic field (RAM-SCB) using, for the first time, data assimilation techniques and particle flux data from the Van Allen Probes. The state of the ring current within the RAM-SCB model is corrected via an ensemble b ... Godinez, Humberto; Yu, Yiqun; Lawrence, Eric; Henderson, Michael; Larsen, Brian; Jordanova, Vania; Published by: Geophysical Research Letters Published on: 11/2016 YEAR: 2016 DOI: 10.1002/2016GL071646 |
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EMIC waves and associated relativistic electron precipitation on 25-26 January 2013 Using measurements from the Van Allen Probes and the Balloon Array for RBSP Relativistic Electron Losses (BARREL), we perform a case study of electromagnetic ion cyclotron (EMIC) waves and associated relativistic electron precipitation (REP) observed on 25\textendash26 January 2013. Among all the EMIC wave and REP events from the two missions, the pair of the events is the closest both in space and time. The Van Allen Probe-B detected significant EMIC waves at L = 2.1\textendash3.9 and magnetic local time (MLT) = 21.0\texten ... Zhang, Jichun; Halford, Alexa; Saikin, Anthony; Huang, Chia-Lin; Spence, Harlan; Larsen, Brian; Reeves, Geoffrey; Millan, Robyn; Smith, Charles; Torbert, Roy; Kurth, William; Kletzing, Craig; Blake, Bernard; Fennel, Joseph; Baker, Daniel; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2016 YEAR: 2016 DOI: 10.1002/2016JA022918 BARREL; EMIC waves; FFT; Geomagnetic storm; relativistic electron precipitation (REP); Van Allen Probes |
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The complex nature of storm-time ion dynamics: Transport and local acceleration Data from the Van Allen Probes Helium, Oxygen, Proton, Electron (HOPE) spectrometers reveal hitherto unresolved spatial structure and dynamics in ion populations. Complex regions of O+ dominance, at energies from a few eV to >10 keV, are observed throughout the magnetosphere. Isolated regions on the dayside that are rich in energetic O+ might easily be interpreted as strong energization of ionospheric plasma. We demonstrate, however, that both the energy spectrum and the limited MLT extent of these features can be explained ... Denton, M.; Reeves, G.; Thomsen, M.; Henderson, M.; Friedel, R.; Larsen, B.; Skoug, R.; Funsten, H.; Spence, H.; Kletzing, C.; Published by: Geophysical Research Letters Published on: 09/2016 YEAR: 2016 DOI: 10.1002/2016GL070878 |
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Hiss or Equatorial Noise? Ambiguities in Analyzing Suprathermal Ion Plasma Wave Resonance Previous studies have shown that low energy ion heating occurs in the magnetosphere due to strong equatorial noise emission. Observations from the Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument recently determined there was a depletion in the 1-10 eV ion population in the post-midnight sector of Earth during quiet times at L < 3. The diurnal variation of equatorially mirroring 1-10 eV H+ ions between 2 < L < 3 is connected with similar diurnal variation in the electric field component of plasma waves rangin ... Sarno-Smith, Lois; Liemohn, Michael; Skoug, Ruth; ik, Ondrej; Morley, Steven; Breneman, Aaron; Larsen, Brian; Reeves, Geoff; Wygant, John; Hospodarsky, George; Kletzing, Craig; Moldwin, Mark; Katus, Roxanne; Zou, Shasha; Published by: Journal of Geophysical Research: Space Physics Published on: 09/2016 YEAR: 2016 DOI: 10.1002/2016JA022975 equatorial noise; Low Energy Ions; plasma waves; plasmasphere; Plasmaspheric Hiss; Van Allen Probes |
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We examine enhancements of energetic (>50 keV) oxygen ions observed by the Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instrument on board the Van Allen Probes spacecraft in the inner magnetosphere (L ~ 6) at 22\textendash23 h magnetic local time (MLT) during an injection event of the 6 June 2013 storm. Simultaneous observations by two Van Allen Probes spacecraft located close together (~0.5 RE) indicate that particle injections occurred in the premidnight sector (< ~24 h MLT). We also examine the evolut ... Keika, Kunihiro; Seki, Kanako; e, Masahito; Machida, Shinobu; Miyoshi, Yoshizumi; Lanzerotti, Louis; Mitchell, Donald; Gkioulidou, Matina; Turner, Drew; Spence, Harlan; Larsen, Brian; Published by: Journal of Geophysical Research: Space Physics Published on: 08/2016 YEAR: 2016 DOI: 10.1002/2016JA022384 adiabatic transport from the plasma sheet; oxygen ions of ionospheric origin; preconditions of magnetic storms; preexisting oxygen ions trapped in the inner magnetosphere; Van Allen Probes; Van Allen Probes RBSPICE observations |
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Local time variations of high-energy plasmaspheric ion pitch angle distributions Recent observations from the Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument revealed a persistent depletion in the 1\textendash10 eV ion population in the postmidnight sector during quiet times in the 2 < L < 3 region. This study explores the source of this ion depletion by developing an algorithm to classify 26 months of pitch angle distributions measured by the HOPE instrument. We correct the HOPE low energy fluxes for spacecraft potential using measurements from the Electric Field and Waves (EFW) instrum ... Sarno-Smith, Lois; Liemohn, Michael; Skoug, Ruth; Larsen, Brian; Moldwin, Mark; Katus, Roxanne; Wygant, John; Published by: Journal of Geophysical Research: Space Physics Published on: 07/2016 YEAR: 2016 DOI: 10.1002/2015JA022301 algorithm; Magnetosphere; pitch angles; plasmasphere; spacecraft potential corrections; Van Allen Probes |
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We investigate magnetic field dipolarization in the inner magnetosphere and its associated ion flux variations, using the magnetic field and energetic ion flux data acquired by the Van Allen Probes. From a study of 74 events that appeared at L = 4.5\textendash6.6 between 1 October 2012 and 31 October 2013, we reveal the following characteristics of the dipolarization in the inner magnetosphere: (1) its timescale is approximately 5 min, (2) it is accompanied by strong magnetic fluctuations that have a dominant frequency close ... e, M.; Keika, K.; Kletzing, C.; Spence, H.; Smith, C.; MacDowall, R.; Reeves, G.; Larsen, B.; Mitchell, D.; Published by: Journal of Geophysical Research: Space Physics Published on: 07/2016 YEAR: 2016 DOI: 10.1002/2016JA022549 Dipolarization; inner magnetosphere; ionospheric outflow; Magnetic Fluctuation; O+ Acceleration; substorm; Van Allen Probes |
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The Source of O + in the Storm-time Ring Current A stretched and compressed geomagnetic field occurred during the main phase of a geomagnetic storm on 1 June 2013. During the storm the Van Allen Probes spacecraft made measurements of the plasma sheet boundary layer, and observed large fluxes of O+ ions streaming up the field line from the nightside auroral region. Prior to the storm main phase there was an increase in the hot (>1 keV) and more isotropic O+ions in the plasma sheet. In the spacecraft inbound pass through the ring current region during the storm main phase, t ... Kistler, L.M.; Mouikis, C.; Spence, H.E.; Menz, A.M.; Skoug, R.M.; Funsten, H.O.; Larsen, B.A.; Mitchell, D.G.; Gkioulidou, M.; Wygant, J.R.; Lanzerotti, L.J.; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2016 YEAR: 2016 DOI: 10.1002/2015JA022204 Geomagnetic storm; Ionosphere; oxygen; plasma sheet; Plasma Sources; ring current; Van Allen Probes |
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Ring current electron dynamics during geomagnetic storms based on the Van Allen Probes measurements Based on comprehensive measurements from Helium, Oxygen, Proton, and Electron Mass Spectrometer Ion Spectrometer, Relativistic Electron-Proton Telescope, and Radiation Belt Storm Probes Ion Composition Experiment instruments on the Van Allen Probes, comparative studies of ring current electrons and ions are performed and the role of energetic electrons in the ring current dynamics is investigated. The deep injections of tens to hundreds of keV electrons and tens of keV protons into the inner magnetosphere occur frequently; a ... Zhao, H.; Li, X.; Baker, D.; Claudepierre, S.; Fennell, J.; Blake, J.; Larsen, B.; Skoug, R.; Funsten, H.; Friedel, R.; Reeves, G.; Spence, H.; Mitchell, D.; Lanzerotti, L.; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2016 YEAR: 2016 DOI: 10.1002/2016JA022358 deep injections; Geomagnetic storms; ring current; ring current energy content; ring current electrons; Van Allen Probes |
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Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes Using the Helium Oxygen Proton Electron (HOPE) and Electric Field and Waves (EFW) instruments from the Van Allen Probes, we explored the relationship between electron energy fluxes in the eV and keV ranges and spacecraft surface charging. We present statistical results on spacecraft charging within geosynchronous orbit by L and MLT. An algorithm to extract the H+ charging line in the HOPE instrument data was developed to better explore intense charging events. Also, this study explored how spacecraft potential relates to ele ... Sarno-Smith, Lois; Larsen, Brian; Skoug, Ruth; Liemohn, Michael; Breneman, Aaron; Wygant, John; Thomsen, Michelle; Published by: Space Weather Published on: 02/2016 YEAR: 2016 DOI: 10.1002/2015SW001345 EFW; HOPE; spacecraft charging; surface charging; Van Allen Probes |
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Nonlinearity in chorus waves during a geomagnetic storm on 1 November 2012 In this study, we investigate the possibility of nonlinearity in chorus waves during a geomagnetic storm on 1 November 2012. The data we use were measured by the Van Allen Probe B. Wave data and plasma sheet electron data are analyzed. Chorus waves were frequently measured in the morning side during the main phase of this storm. Large-amplitude chorus waves were seen of the order of \~0.6 nT and >7 mV/m, which are similar to or larger than the typical ULF waves. The waves quite often consist of rising tones during the burst ... Matsui, H.; Paulson, K.; Torbert, R.; Spence, H.; Kletzing, C.; Kurth, W.; Skoug, R.; Larsen, B.; Breneman, A.; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2016 YEAR: 2016 DOI: 10.1002/2015JA021772 chorus waves; Geomagnetic storm; nonlinearity; Van Allen Probes |
| 2015 |
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Energy dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions. We present observations of the radiation belts from the HOPE and MagEIS particle detectors on the Van Allen Probes satellites that illustrate the energy-dependence and L-shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on March 1 in more detail. The observations show: (a) At all L-shells, lower-energy electrons are enhanced more often than higher energies; (b) Events that fill the slot region are more common at lower energies; (c) Enhancements of electrons in the inner ... Reeves, Geoffrey; Friedel, Reiner; Larsen, Brian; Skoug, Ruth; Funsten, Herbert; Claudepierre, Seth; Fennell, Joseph; Turner, Drew; Denton, Mick; Spence, H.; Blake, Bernard; Baker, D.; Published by: Journal of Geophysical Research: Space Physics Published on: 12/2015 YEAR: 2015 DOI: 10.1002/2015JA021569 Acceleration; energetic particles; Inner zone; Outer Zone; Radiation belts; Slot region; Van Allen Probes |
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\textquotedblleftTrunk-like\textquotedblright heavy ion structures observed by the Van Allen Probes Dynamic ion spectral features in the inner magnetosphere are the observational signatures of ion acceleration, transport, and loss in the global magnetosphere. We report \textquotedbllefttrunk-like\textquotedblright ion structures observed by the Van Allen Probes on 2 November 2012. This new type of ion structure looks like an elephant\textquoterights trunk on an energy-time spectrogram, with the energy of the peak flux decreasing Earthward. The trunks are present in He+ and O+ ions but not in H+. During the event, ion energ ... Zhang, J.-C.; Kistler, L.; Spence, H.; Wolf, R.; Reeves, G.; Skoug, R.; Funsten, H.; Larsen, B.; Niehof, J.; MacDonald, E.; Friedel, R.; Ferradas, C.; Luo, H.; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2015 YEAR: 2015 DOI: 10.1002/2015JA021822 inner magnetosphere; ion injection; Ion structure; magnetic cloud; magnetic storm; Van Allen Probes |
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Enabled by the comprehensive measurements from the MagEIS, HOPE, and RBSPICE instruments onboard Van Allen Probes in the heart of the radiation belt, the relative contributions of ions with different energies and species to the ring current energy density and their dependence on the phases of geomagnetic storms are quantified. The results show that lower energy (<50 keV) protons enhance much more often and also decay much faster than higher energy protons. During the storm main phase, ions with energies < 50 keV contribute m ... Zhao, H.; Li, X.; Baker, D.; Fennell, J.; Blake, J.; Larsen, B.; Skoug, R.; Funsten, H.; Friedel, R.; Reeves, G.; Spence, H.; Mitchell, D.; Lanzerotti, L.; Rodriguez, J.; Published by: Journal of Geophysical Research: Space Physics Published on: 08/2015 YEAR: 2015 DOI: 10.1002/2015JA021533 Geomagnetic storms; Ring current energy content; Ring current ions; The DPS relation; The Dst index; Van Allen Probes |
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A background correction algorithm for Van Allen Probes MagEIS electron flux measurements We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes MagEIS electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagE ... Claudepierre, S.; O\textquoterightBrien, T.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Looper, M.; Mazur, J.; Mulligan, T.; Spence, H.; Reeves, G.; Friedel, R.; Henderson, M.; Larsen, B.; Published by: Journal of Geophysical Research: Space Physics Published on: 06/2015 YEAR: 2015 DOI: 10.1002/2015JA021171 Background contamination; Inner radiation belt; outer radiation belt; Particle measurements; Radiation belt; Spacecraft engineering; Van Allen Probes |
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The twin Van Allen Probes spacecraft witnessed a series of lobe encounters between 0200 and 0515 UT on November 14th 2012. Although lobe entry had been observed previously by the other spacecraft, the two Van Allen Probe spacecraft allow us to observe the motion of the boundary for the first time. Moreover, this event is unique in that it consists of a series of six quasi-periodic lobe entries. The events occurred on the dawn flank between 4 and 6.6 local time and at altitudes between 5.6 and 6.2 RE. During the events Dst dr ... Dixon, P.; MacDonald, E.; Funsten, H.; Glocer, A.; Grande, M.; Kletzing, C.; Larsen, B.; Reeves, G.; Skoug, R.; Spence, H.; Thomsen, M.; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2015 YEAR: 2015 DOI: 10.1002/2014JA020883 Lobes; Magnetosphere; Modelling; Open/closed field line boundary; Van Allen Probes |
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Electric field structures and waves at plasma boundaries in the inner magnetosphere Recent observations by the Van Allen Probes spacecraft have demonstrated that a variety of electric field structures and nonlinear waves frequently occur in the inner terrestrial magnetosphere, including phase space holes, kinetic field line resonances, nonlinear whistler mode waves, and several types of double layer. However, it is unclear whether such structures and waves have a significant impact on the dynamics of the inner magnetosphere, including the radiation belts and ring current. To make progress toward quantifying ... Malaspina, David; Wygant, John; Ergun, Robert; Reeves, Geoff; Skoug, Ruth; Larsen, Brian; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2015 YEAR: 2015 DOI: 10.1002/2015JA021137 injection; inner magnetosphere; nonlinear electric field structures; plasma boundary; plasma sheet; Van Allen Probes |
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Postmidnight depletion of the high-energy tail of the quiet plasmasphere The Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument measures the high-energy tail of the thermal plasmasphere allowing study of topside ionosphere and inner magnetosphere coupling. We statistically analyze a 22 month period of HOPE data, looking at quiet times with a Kp index of less than 3. We investigate the high-energy range of the plasmasphere, which consists of ions at energies between 1 and 10 eV and contains approximately 5\% of total plasmaspheric density. Both the fluxes and partial plasma densities ... Sarno-Smith, Lois; Liemohn, Michael; Katus, Roxanne; Skoug, Ruth; Larsen, Brian; Thomsen, Michelle; Wygant, John; Moldwin, Mark; Published by: Journal of Geophysical Research: Space Physics Published on: 03/2015 YEAR: 2015 DOI: 10.1002/2014JA020682 ion composition; Ionosphere; plasmasphere; postmidnight; quiet time magnetosphere; Van Allen Probes |
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Study of EMIC wave excitation using direct ion measurements With data from Van Allen Probes, we investigate EMIC wave excitation using simultaneously observed ion distributions. Strong He-band waves occurred while the spacecraft was moving through an enhanced density region. We extract from Helium, Oxygen, Proton, and Electron (HOPE) Mass Spectrometer measurement the velocity distributions of warm heavy ions as well as anisotropic energetic protons that drive wave growth through the ion cyclotron instability. Fitting the measured ion fluxes to multiple sinm-type distribution function ... Min, Kyungguk; Liu, Kaijun; Bonnell, John; Breneman, Aaron; Denton, Richard; Funsten, Herbert; Jahn, öerg-Micha; Kletzing, Craig; Kurth, William; Larsen, Brian; Reeves, Geoffrey; Spence, Harlan; Wygant, John; Published by: Journal of Geophysical Research: Space Physics Published on: 03/2015 YEAR: 2015 DOI: 10.1002/2014JA020717 EMIC wave excitation; observation; linear theory and hybrid simulation; Van Allen Probes |
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Formation of the oxygen torus in the inner magnetosphere: Van Allen Probes observations We study the formation process of an oxygen torus during the 12\textendash15 November 2012 magnetic storm, using the magnetic field and plasma wave data obtained by Van Allen Probes. We estimate the local plasma mass density (ρL) and the local electron number density (neL) from the resonant frequencies of standing Alfv\ en waves and the upper hybrid resonance band. The average ion mass (M) can be calculated by M \~ ρL/neL under the assumption of quasi-neutrality of plasma. During the storm recovery phase, both Probe A and ... e, Nos\; Oimatsu, S.; Keika, K.; Kletzing, C.; Kurth, W.; De Pascuale, S.; Smith, C.; MacDowall, R.; Nakano, S.; Reeves, G.; Spence, H.; Larsen, B.; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2015 YEAR: 2015 DOI: 10.1002/2014JA020593 inner magnetosphere; magnetic storm; oxygen torus; plasmasphere; ring current; ULF waves; Van Allen Probes |
| 2014 |
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Magnetospheric banded chorus is enhanced whistler waves with frequencies ωr < Ωe, where Ωe is the electron cyclotron frequency, and a characteristic spectral gap at ωr ≃ Ωe/2. This paper uses spacecraft observations and two-dimensional particle-in-cell (PIC) simulations in a magnetized, homogeneous, collisionless plasma to test the hypothesis that banded chorus is due to local linear growth of two branches of the whistler anisotropy instability excited by two distinct, anisotropic electron components of significantly ... Fu, Xiangrong; Cowee, Misa; Friedel, Reinhard; Funsten, Herbert; Gary, Peter; Hospodarsky, George; Kletzing, Craig; Kurth, William; Larsen, Brian; Liu, Kaijun; MacDonald, Elizabeth; Min, Kyungguk; Reeves, Geoffrey; Skoug, Ruth; Winske, Dan; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2014 YEAR: 2014 DOI: 10.1002/2014JA020364 |
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Simulation of Van Allen Probes Plasmapause Encounters We use an E \texttimes B-driven plasmapause test particle (PTP) simulation to provide global contextual information for in situ measurements by the Van Allen Probes (RBSP) during 15\textendash20 January 2013. During 120 h of simulation time beginning on 15 January, geomagnetic activity produced three plumes. The third and largest simulated plume formed during enhanced convection on 17 January, and survived as a rotating, wrapped, residual plume for tens of hours. To validate the simulation, we compare its output with RBSP da ... Goldstein, J.; De Pascuale, S.; Kletzing, C.; Kurth, W.; Genestreti, K.; Skoug, R.; Larsen, B.; Kistler, L.; Mouikis, C.; Spence, H.; Published by: Journal of Geophysical Research: Space Physics Published on: 09/2014 YEAR: 2014 DOI: 10.1002/2014JA020252 observations; plasmasphere; residual plume; simulation; Van Allen Probes |
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