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Van Allen Probes Bibliography is from August 2012 through September 2021 Notice:
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Found 53 entries in the Bibliography.
Showing entries from 1 through 50
| 2021 |
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Plain Language Summary The plasmasphere is the region filled with cold, dense ionized gas in geospace. The ionized gas mainly consists in protons, helium ions, oxygen ions and electrons, which come from Earth’s ionosphere and fill in magnetic flux tubes. The density distribution of the ionized gas along the flux tube provides important information to understand how the ions and electrons have been supplied from the ionosphere. Many satellites fly in the equatorial plane, hence, do not provide information on the electron de ... Obana, Yuki; Miyashita, Yukinaga; Maruyama, Naomi; Shinbori, Atsuki; Nosé, Masahito; Shoji, Masafumi; Kumamoto, Atsushi; Tsuchiya, Fuminori; Matsuda, Shoya; Matsuoka, Ayako; Kasahara, Yoshiya; Miyoshi, Yoshizumi; Shinohara, Iku; Kurth, William; Smith, Charles; MacDowall, Robert; Published by: Journal of Geophysical Research: Space Physics Published on: 09/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA029073 plasmasphere; inner magnetosphere; Arase satellite; Van Allen Probes satellite; simultaneous observation; Geomagnetic storm; Van Allen Probes |
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Global Survey of Electron Precipitation due to Hiss Waves in the Earth s Plasmasphere and Plumes Abstract We present a global survey of energetic electron precipitation from the equatorial magnetosphere due to hiss waves in the plasmasphere and plumes. Using Van Allen Probes measurements, we calculate the pitch angle diffusion coefficients at the bounce loss cone, and evaluate the energy spectrum of precipitating electron flux. Our ∼6.5-year survey shows that, during disturbed times, hiss inside the plasmasphere primarily causes the electron precipitation at L > 4 over 8 h < MLT < 18 h, and hiss waves in plumes cause ... Ma, Q.; Li, W.; Zhang, X.-J.; Bortnik, J.; Shen, X.-C.; Connor, H.; Boyd, A.; Kurth, W.; Hospodarsky, G.; Claudepierre, S.; Reeves, G.; Spence, H.; Published by: Journal of Geophysical Research: Space Physics Published on: 07/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2021JA029644 electron precipitation; hiss wave; plasmasphere; plasmaspheric plume; Precipitating Energy Flux; Van Allen Probes Survey; Van Allen Probes |
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The Roles of the Magnetopause and Plasmapause in Storm-Time ULF Wave Power Enhancements Abstract Ultra Low Frequency (ULF) waves play a crucial role in transporting and coupling energy within the magnetosphere. During geomagnetic storms, dayside magnetospheric ULF wave power is highly variable with strong enhancements that are dominated by elevated solar wind driving. However, the radial distribution of ULF wave power is complex - controlled interdependently by external solar wind driving and the internal magnetospheric structuring. We conducted a statistical analysis of observed storm-time ULF wave power from ... Sandhu, J.; Rae, I.; Staples, F.; Hartley, D.; Walach, M.-T.; Elsden, T.; Murphy, K.; Published by: Journal of Geophysical Research: Space Physics Published on: 06/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2021JA029337 ULF waves; Geomagnetic storms; Van Allen Probes; radial diffusion; inner magnetosphere; plasmasphere |
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Abstract We present a comparison of magnetospheric plasma mass/electron density observations during an 11-day interval which includes the geomagnetic storm of 22 June 2015. For this study we used: equatorial plasma mass density derived from geomagnetic field line resonances (FLRs) detected by Van Allen Probes and at the ground-based magnetometer networks EMMA and CARISMA; in situ electron density inferred by the Neural-network-based Upper hybrid Resonance Determination algorithm applied to plasma wave Van Allen Probes measur ... Vellante, M.; Takahashi, K.; Del Corpo, A.; Zhelavskaya, I.; Goldstein, J.; Mann, I.; Pietropaolo, E.; Reda, J.; Heilig, B.; Published by: Journal of Geophysical Research: Space Physics Published on: 06/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2021JA029292 magnetoseismology; plasmasphere; Field line resonance; ground-based magnetometers; Van Allen Probes; Swarm satellites |
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Abstract This paper presents results from a numerical study of the guiding of VLF whistler-mode waves along the ambient magnetic field by the shelf-like density structures observed by the NASA Van Allen Probes satellites in the equatorial plasmasphere. The shelf-duct consists of a homogeneous central part “sandwiched” between two density gradients pointing in the same direction. To the best of our knowledge, this type of whistler ducting has never been identified in observations before. Our investigation is based on simu ... Published by: Journal of Geophysical Research: Space Physics Published on: 05/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2021JA029403 Whistler waves; density duct; plasmasphere; RBSP; simulations; Van Allen Probes |
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Abstract We study packages of VLF whistler-mode waves observed by the Van Allen Probes satellites in the equatorial plasmasphere. We demonstrate that the main mechanism providing localization of these waves inside relatively broad (>1 RE across the ambient magnetic field) magnetospheric regions is a combined effect of the transverse gradients in the plasma density and the ambient magnetic field. The criterion for the wave trapping by these gradients is the same as for the wave trapping inside a high-density duct with a symme ... Published by: Journal of Geophysical Research: Space Physics Published on: 02/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA028933 density inhomogeneity; duct; Plasmapause; plasmasphere; VLF waves; whistler; Van Allen Probes |
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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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AbstractIn-situ electron density profiles obtained from Arase in the night magnetic local time (MLT) sector and from RBSP-B covering all MLTs are used to study the small-scale density irregularities present in the plasmasphere and near the plasmapause. Electron density perturbations with amplitudes > 10\% from background density and with time-scales less than 30-min are investigated here as the small-scale density irregularities. The statistical survey of the density irregularities is carried out using nearly two years of de ... Thomas, Neethal; Shiokawa, Kazuo; Miyoshi, Yoshizumi; Kasahara, Yoshiya; Shinohara, Iku; Kumamoto, Atsushi; Tsuchiya, Fuminori; Matsuoka, Ayako; Kasahara, Satoshi; Yokota, Shoichiro; Keika, Kunihiro; Hori, Tomo; Asamura, Kazushi; Wang, Shiang-Yu; Kazama, Yoichi; Tam, Sunny; Chang, Tzu-Fang; Wang, Bo-Jhou; Wygant, John; Breneman, Aaron; Reeves, Geoff; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA027917 Electron density; small-scale density irregularities; plasmasphere; inner magnetosphere; Van Allen Probes; Arase |
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A combined neural network- and physics-based approach for modeling plasmasphere dynamics AbstractIn recent years, feedforward neural networks (NNs) have been successfully applied to reconstruct global plasmasphere dynamics in the equatorial plane. These neural network-based models capture the large-scale dynamics of the plasmasphere, such as plume formation and erosion of the plasmasphere on the nightside. However, their performance depends strongly on the availability of training data. When the data coverage is limited or non-existent, as occurs during geomagnetic storms, the performance of NNs significantly de ... Zhelavskaya, I.; Aseev, N.; Shprits, Y; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2021 YEAR: 2021 DOI: https://doi.org/10.1029/2020JA028077 plasmasphere; plasma density; neural networks; data assimilation; Kalman Filter; Machine learning; Van Allen Probes |
| 2020 |
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We present new and previously unreported in situ observations of Hertz frequency multiharmonic mode field line resonances detected by the Electric Field and Waves instrument on-board the NASA Van Allen probes during low-L perigee passes. Spectral analysis of the spin-plane electric field data reveals the waves in numerous perigee passes, in sequential passes of probes A and B, and with harmonic frequency structures from ∼0.5 to 3.5 Hz which vary with L-shell, altitude, and from day-to-day. Comparing the observations to wa ... Lena, F.; Ozeke, L.; Wygant, J.; Tian, S.; Breneman, A.; Mann, I.; Published by: Geophysical Research Letters Published on: 12/2020 YEAR: 2020 DOI: https://doi.org/10.1029/2020GL090632 Field line resonance; Ionosphere; magneto-seismology; Magnetosphere; plasmasphere; standing Alfvén waves; Van Allen Probes |
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Whistler-mode hiss waves generally determine MeV electron lifetimes inside the plasmasphere. We use Van Allen Probes measurements to provide the first comprehensive statistical survey of plasmaspheric hiss-driven quasi-linear pitch-angle diffusion rates and lifetimes of MeV electrons as a function of L*, local time, and AE index, taking into account hiss power, electron plasma frequency to gyrofrequency ratio ωpe/Ωce, hiss frequency at peak power ωm, and cross correlations of these parameters. We find that during geomagne ... Agapitov, O.; Mourenas, D.; Artemyev, A.; Claudepierre, S.; Hospodarsky, G.; Bonnell, J.; Published by: Geophysical Research Letters Published on: 05/2020 YEAR: 2020 DOI: https://doi.org/10.1029/2020GL088052 electron lifetimes; plasmasphere; hiss waves; wave-particle interactions; Van Allen Probes |
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Abstract A comprehensive numerical raytracing study of whistler mode wave power with the inclusion of finite background electron and ion temperature is performed in order to investigate wave power distribution in relation to the plasmapause. Both Landau damping and linear growth of whistler mode waves are taken into account using a bi-Maxwellian hot electron distribution as well as an isotropic hot electron distribution. Isotropic and bi-Maxwellian distributions yield similar results of statistical spatial wave power for fre ... Maxworth, A.; Gołkowski, M.; Malaspina, D.; Jaynes, A.; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2020 YEAR: 2020 DOI: 10.1029/2019JA027154 hiss; plasmasphere; Warm Plasma; Raytracing; Magnetosphere; Van Allen Probes |
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A comprehensive numerical raytracing study of whistler mode wave power with the inclusion of finite background electron and ion temperature is performed in order to investigate wave power distribution in relation to the plasmapause. Both Landau damping and linear growth of whistler mode waves are taken into account using a bi-Maxwellian hot electron distribution as well as an isotropic hot electron distribution. Isotropic and bi-Maxwellian distributions yield similar results of statistical spatial wave power for frequencies ... Maxworth, A.; Gołkowski, M.; Malaspina, D.; Jaynes, A.; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2020 YEAR: 2020 DOI: https://doi.org/10.1029/2019JA027154 hiss; plasmasphere; Warm Plasma; Raytracing; Magnetosphere; Van Allen Probes |
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Plasmaspheric hiss is an important whistler-mode emission shaping the Van Allen radiation belt environment. How the plasmaspheric hiss waves are generated, propagate, and dissipate remains under intense debate. With the five spacecraft of Van Allen Probes, Exploration of energization and Radiation in Geospace (Arase), and Geostationary Operational Environmental Satellites missions at widely spaced locations, we present here the first comprehensive observations of hiss waves growing from the substorm-injected electron instabi ... Liu, Nigang; Su, Zhenpeng; Gao, Zhonglei; Zheng, Huinan; Wang, Yuming; Wang, Shui; Miyoshi, Yoshizumi; Shinohara, Iku; Kasahara, Yoshiya; Tsuchiya, Fuminori; Kumamoto, Atsushi; Matsuda, Shoya; Shoji, Masafumi; Mitani, Takefumi; Takashima, Takeshi; Kazama, Yoichi; Wang, Bo-Jhou; Wang, Shiang-Yu; Jun, Chae-Woo; Chang, Tzu-Fang; W. Y. Tam, Sunny; Kasahara, Satoshi; Yokota, Shoichiro; Keika, Kunihiro; Hori, Tomoaki; Matsuoka, Ayako; Published by: Geophysical Research Letters Published on: 01/2020 YEAR: 2020 DOI: 10.1029/2019GL086040 plasmasphere; Plasmaspheric Hiss; Radiation belt; Van Allen Probes; Wave Dissipation; wave generation; wave propagation |
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The plasmasphere is a critical region of the magnetosphere. It is important for the evolution of Earth\textquoterights radiation belts. Waves in the plasmasphere interior (hiss) and vicinity (EMIC, chorus) help control the acceleration and loss of radiation belt particles. Thus, understanding the extent, structure, content, and dynamics of the plasmasphere is crucial to understanding radiation belt losses. The Van Allen Probes mission uses two methods to determine the total plasma density. First, the upper hybrid resonance ( ... Jahn, J.-M.; Goldstein, J.; Kurth, W.S.; Thaller, S.; De Pascuale, S.; Wygant, J.; Reeves, G.D.; Spence, H.E.; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2020 YEAR: 2020 DOI: 10.1029/2019JA026860 cold plasma density; plasmasphere; spacecraft charging; Van Allen Probes; wave resonances |
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Abstract Plasmaspheric hiss is an important whistler-mode emission shaping the Van Allen radiation belt environment. How the plasmaspheric hiss waves are generated, propagate, and dissipate remains under intense debate. With the five spacecraft of Van Allen Probes, Exploration of energization and Radiation in Geospace (Arase), and Geostationary Operational Environmental Satellites missions at widely spaced locations, we present here the first comprehensive observations of hiss waves growing from the substorm-injected electro ... Liu, Nigang; Su, Zhenpeng; Gao, Zhonglei; Zheng, Huinan; Wang, Yuming; Wang, Shui; Miyoshi, Yoshizumi; Shinohara, Iku; Kasahara, Yoshiya; Tsuchiya, Fuminori; Kumamoto, Atsushi; Matsuda, Shoya; Shoji, Masafumi; Mitani, Takefumi; Takashima, Takeshi; Kazama, Yoichi; Wang, Bo-Jhou; Wang, Shiang-Yu; Jun, Chae-Woo; Chang, Tzu-Fang; W. Y. Tam, Sunny; Kasahara, Satoshi; Yokota, Shoichiro; Keika, Kunihiro; Hori, Tomoaki; Matsuoka, Ayako; Published by: Geophysical Research Letters Published on: YEAR: 2020 DOI: 10.1029/2019GL086040 Plasmaspheric Hiss; Radiation belt; plasmasphere; wave generation; wave propagation; Wave Dissipation |
| 2019 |
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Two wave packets of second harmonic poloidal Pc 4 waves with a wave frequency of ~7 mHz were detected by Van Allen Probe A at a radial distance of ~5.8 RE and magnetic local time of 13 hr near the magnetic equator, where plasmaspheric refilling was in progress. Proton butterfly distributions with energy dispersions were also measured at the same time; the proton fluxes at 10-30 keV oscillated with the same frequency as the Pc 4 waves. Using the ion sounding technique, we find that the Pc 4 waves propagated eastward with an a ... Yamamoto, K.; e, Nos\; Keika, K.; Hartley, D.P.; Smith, C.W.; MacDowall, R.J.; Lanzerotti, L.J.; Mitchell, D.G.; Spence, H.E.; Reeves, G.D.; Wygant, J.R.; Bonnell, J.W.; Oimatsu, S.; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2019 YEAR: 2019 DOI: 10.1029/2019JA027158 drift-bounce resonance; Geomagnetic storm; plasmasphere; ring current; substorm; ULF wave; Van Allen Probes |
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Epoch-Based Model for Stormtime Plasmapause Location The output of a plasmapause test particle (PTP) code is used to formulate a new epoch-based plasmapause model. The PTP simulation is run for an ensemble of 60 storms spanning 3 September 2012 to 28 September 2017 and having peak Dst of -60 nT or less, yielding over 7 million model plasmapause locations. Events are automatically identified and epoch times calculated relative to the respective storm peaks. Epoch analysis of the simulated plasmapause is demonstrated to be an effective method to reveal the dynamical phases of pl ... Goldstein, J.; De Pascuale, S.; Kurth, W.; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2019 YEAR: 2019 DOI: 10.1029/2018JA025996 epoch-based model; Plasmapause; plasmasphere; plume; Van Allen Probes |
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Equatorial noise (EN) emissions are observed inside and outside the plasmapause. EN emissions are referred to as magnetosonic mode waves. Using data from Van Allen Probes and Arase, we found conversion from EN emissions to electromagnetic ion cyclotron (EMIC) waves in the plasmasphere and in the topside ionosphere. A low frequency part of EN emissions becomes EMIC waves through branch splitting of EN emissions, and the mode conversion from EN to EMIC waves occurs around the frequency of M/Q=2 (deuteron and/or alpha particles ... Miyoshi, Y.; Matsuda, S.; Kurita, S.; Nomura, K.; Keika, K.; Shoji, M.; Kitamura, N.; Kasahara, Y.; Matsuoka, A.; Shinohara, I.; Shiokawa, K.; Machida, S.; Santolik, O.; Boardsen, S.A.; Horne, R.B.; Wygant, J.F.; Published by: Geophysical Research Letters Published on: 04/2019 YEAR: 2019 DOI: 10.1029/2019GL083024 Arase; EMIC; M/Q=2 ions; Magnetsonic waves; plasmasphere; Van Allen Probes |
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Satellite-based direct electric field measurements deliver crucial information for space science studies. Yet they require meticulous design and calibration. In-flight calibration of double-probe instruments is usually presented in the most common case of tenuous plasmas, where the presence of an electrostatic structure surrounding the charged spacecraft alters the geophysical electric field measurements. To account for this effect and the uncertainty in the boom length, the measured electric field is multiplied by a paramet ... Published by: Earth and Space Science Published on: 04/2019 YEAR: 2019 DOI: 10.1029/2018EA000550 DC electric field; double probe instrument; electric drift; plasmasphere; shorting factor; Van Allen Probes |
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This paper presents the first analysis of Van Allen Probes measurements of the cold plasma density and electric field in the inner magnetosphere to show that intervals of strong modulation at the solar rotation period occur in the locations of the outer plasmasphere and plasmapause (~0.7 RE peak-to-peak), in the large-scale electric field (~0.24 mV/m peak-to-peak), and in the cold plasma density (~250 cm-3 \textendash ~70 cm-3 peak-to-peak). Solar rotation modulation of the inner magnetosphere is more apparent in the declini ... Thaller, S.; Wygant, J.; Cattell, C.; Breneman, A.; Tyler, E.; Tian, S.; Engel, A.; De Pascuale, S.; Kurth, W.; Kletzing, C.; Tears, J.; Malaspina, David; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2019 YEAR: 2019 DOI: 10.1029/2018JA026365 convection electric field; inner magnetosphere; Plasmapause; plasmasphere; solar rotation; Van Allen Probes |
| 2018 |
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Simulations of Van Allen Probes Plasmaspheric Electron Density Observations We simulate equatorial plasmaspheric electron densities using a physics-based model (Cold PLasma, CPL; used in the ring current-atmosphere interactions model) of the source and loss processes of refilling and erosion driven by empirical inputs. The performance of CPL is evaluated against in situ measurements by the Van Allen Probes (Radiation Belt Storm Probes) for two events: the 31 May to 5 June and 15 to 20 January 2013 geomagnetic storms observed in the premidnight and postmidnight magnetic local time (MLT) sectors, resp ... De Pascuale, S.; Jordanova, V.; Goldstein, J.; Kletzing, C.; Kurth, W.; Thaller, S.; Wygant, J.; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2018 YEAR: 2018 DOI: 10.1029/2018JA025776 convection; observations; plasmasphere; RBSP; simulation; Van Allen Probes |
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Using Van Allen Probes\textquoteright observations and established plasmapause location (Lpp) models, we investigate the relationship between the location of the initial enhancement (IE) of energetic electrons and the innermost (among all magnetic local time sectors) Lpp over five intense storm periods. Our study reveals that the IE events for 30 keV to 2MeV electrons always occurred outside of the innermost Lpp. On average, the inner extent of the IE events (LIE) for <800 keV electrons was closer to the innermost Lpp when c ... Khoo, Leng; Li, Xinlin; Zhao, Hong; Sarris, Theodore; Xiang, Zheng; Zhang, Kun; Kellerman, Adam; Blake, Bernard; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2018 YEAR: 2018 DOI: 10.1029/2018JA026074 energetic electron; enhancements; plasmasphere; Radiation belt; Van Allen Probes |
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Determining Plasmaspheric Densities from Observations of Plasmaspheric Hiss A new method of inferring electron plasma densities inside of the plasmasphere is presented. Utilizing observations of the electric and magnetic field wave power associated with plasmaspheric hiss, coupled with the cold plasma dispersion relation, permits calculation of the plasma density. This methodology yields a density estimate for each frequency channel and time interval where plasmaspheric hiss is observed and is shown to yield results that are generally in agreement with densities determined via other methods. A stati ... Hartley, D.; Kletzing, C.; De Pascuale, S.; Kurth, W.; ik, O.; Published by: Journal of Geophysical Research: Space Physics Published on: 08/2018 YEAR: 2018 DOI: 10.1029/2018JA025658 Density; EMFISIS; plasmasphere; Plasmaspheric Hiss; Van Allen Probes |
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Global model of plasmaspheric hiss from multiple satellite observations We present a global model of plasmaspheric hiss, using data from eight satellites, extending the coverage and improving the statistics of existing models. We use geomagnetic activity dependent templates to separate plasmaspheric hiss from chorus. In the region 22-14 MLT the boundary between plasmaspheric hiss and chorus moves to lower L* values with increasing geomagnetic activity. The average wave intensity of plasmaspheric hiss is largest on the dayside and increases with increasing geomagnetic activity from midnight throu ... Meredith, Nigel; Horne, Richard; Kersten, Tobias; Li, Wen; Bortnik, Jacob; Sicard-Piet, elica; Yearby, Keith; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2018 YEAR: 2018 DOI: 10.1029/2018JA025226 plasmasphere; Plasmaspheric Hiss; Radiation belts; Van Allen Probes |
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Magnetic activity dependence of the electric drift below L=3 More than two years of magnetic and electric field measurements by the Van Allen Probes are analyzed with the objective of determining the average effects of magnetic activity on the electric drift below L=3. The study finds that an increase in magnetospheric convection leads to a decrease in the magnitude of the azimuthal component of the electric drift, especially in the night-side. The amplitude of the slowdown is a function of L, local time MLT, and Kp, in a pattern consistent with the storm-time dynamics of the ionosphe ... Published by: Geophysical Research Letters Published on: 04/2018 YEAR: 2018 DOI: 10.1029/2018GL077873 electric drift; electric field; Inner radiation belt; ionospheric disturbance dynamo; plasmasphere; subcorotation; Van Allen Probes |
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Van Allen Probes Observations of Second Harmonic Poloidal Standing Alfv\ en Waves Long-lasting second-harmonic poloidal standing Alfv\ en waves (P2 waves) were observed by the twin Van Allen Probes (Radiation Belt Storm Probes, or RBSP) spacecraft in the noon sector of the plasmasphere, when the spacecraft were close to the magnetic equator and had a small azimuthal separation. Oscillations of proton fluxes at the wave frequency (\~10 mHz) were also observed in the energy (W) range 50\textendash300 keV. Using the unique RBSP orbital configuration, we determined the phase delay of magnetic field perturbati ... Takahashi, Kazue; Oimatsu, Satoshi; e, Masahito; Min, Kyungguk; Claudepierre, Seth; Chan, Anthony; Wygant, John; Kim, Hyomin; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2018 YEAR: 2018 DOI: 10.1002/2017JA024869 bounce and drift-bounce resonances; energetic protons; plasmasphere; poloidal ULF waves; second harmonic; Van Allen Probes |
| 2017 |
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Empirical modeling of the plasmasphere dynamics using neural networks We propose a new empirical model for reconstructing the global dynamics of the cold plasma density distribution based only on solar wind data and geomagnetic indices. Utilizing the density database obtained using the NURD (Neural-network-based Upper hybrid Resonance Determination) algorithm for the period of October 1, 2012 - July 1, 2016, in conjunction with solar wind data and geomagnetic indices, we develop a neural network model that is capable of globally reconstructing the dynamics of the cold plasma density distributi ... Zhelavskaya, Irina; Shprits, Yuri; c, Maria; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2017 YEAR: 2017 DOI: 10.1002/2017JA024406 inner magnetosphere; Machine learning; Models; neural networks; plasmasphere; Van Allen Probes |
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Plasmaspheric rotation is known to lag behind Earth rotation. The causes for this corotation lag are not yet fully understood. We have used more than two years of Van Allen Probe observations to compare the electric drift measured below L~2 with the predictions of a general model. In the first step, a rigid corotation of the ionosphere with the solid Earth was assumed in the model. The results of the model-observation comparison are twofold: (1) radially, the model explains the average observed geographic variability of the ... Lejosne, ène; Maus, Stefan; Mozer, F.; Published by: Geophysical Research Letters Published on: 07/2017 YEAR: 2017 DOI: 10.1002/2017GL074862 corotation; electric field; Ionosphere; plasmasphere; thermosphere; Van Allen Probes; wind |
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Externally driven plasmaspheric ULF waves observed by the Van Allen Probes We analyze data acquired by the Van Allen Probes on 8 November 2012, during a period of extended low geomagnetic activity, to gain new insight into plasmaspheric ultralow frequency (ULF) waves. The waves exhibited strong spectral power in the 5\textendash40 mHz band and included multiharmonic toroidal waves visible up to the eleventh harmonic, unprecedented in the plasmasphere. During this wave activity, the interplanetary magnetic field cone angle was small, suggesting that the waves were driven by broadband compressional U ... Takahashi, Kazue; Denton, Richard; Kurth, William; Kletzing, Craig; Wygant, John; Bonnell, John; Dai, Lei; Min, Kyungguk; Smith, Charles; MacDowall, Robert; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2017 YEAR: 2017 DOI: 10.1002/2014JA020373 multispacecraft observation; plasmasphere; ULF waves; Van Allen Probes |
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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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The electric drift E \texttimes B/B2 plays a fundamental role for the description of plasma flow and particle acceleration. Yet it is not well-known in the inner belt and slot region because of a lack of reliable in situ measurements. In this article, we present an analysis of the electric drifts measured below L ~ 3 by both Van Allen Probes A and B from September 2012 to December 2014. The objective is to determine the typical components of the equatorial electric drift in both radial and azimuthal directions. The dependenc ... Published by: Journal of Geophysical Research: Space Physics Published on: 12/2016 YEAR: 2016 DOI: 10.1002/2016JA023613 electric drift; electric field; Inner radiation belt; plasmasphere; subcorotation; Van Allen Probes |
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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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The distribution of plasmaspheric hiss wave power with respect to plasmapause location In this work, Van Allen Probes data are used to derive terrestrial plasmaspheric hiss wave power distributions organized by (1) distance away from the plasmapause and (2) plasmapause distance from Earth. This approach is in contrast to the traditional organization of hiss wave power by L parameter and geomagnetic activity. Plasmapause-sorting reveals previously unreported and highly repeatable features of the hiss wave power distribution, including a regular spatial distribution of hiss power with respect to the plasmapause, ... Malaspina, David; Jaynes, Allison; e, Cory; Bortnik, Jacob; Thaller, Scott; Ergun, Robert; Kletzing, Craig; Wygant, John; Published by: Geophysical Research Letters Published on: 08/2016 YEAR: 2016 DOI: 10.1002/2016GL069982 hiss; plasma waves; plasmasphere; Radiation belts; Van Allen Probes |
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Propagation of ULF waves from the upstream region to the midnight sector of the inner magnetosphere Ultralow frequency (ULF) waves generated in the ion foreshock are a well-known source of Pc3-Pc4 waves (7\textendash100 mHz) observed in the dayside magnetosphere. We use data acquired on 10 April 2013 by multiple spacecraft to demonstrate that ULF waves of upstream origin can propagate to the midnight sector of the inner magnetosphere. At 1130\textendash1730 UT on the selected day, the two Van Allen Probes spacecraft and the geostationary ETS-VIII satellite detected compressional 20 to 40 mHz magnetic field oscillations bet ... Takahashi, Kazue; Hartinger, Michael; Malaspina, David; Smith, Charles; Koga, Kiyokazu; Singer, Howard; ühauff, Dennis; Baishev, Dmitry; Moiseev, Alexey; Yoshikawa, Akimasa; Published by: Journal of Geophysical Research: Space Physics Published on: 08/2016 YEAR: 2016 DOI: 10.1002/2016JA022958 midnight sector; Pc3 waves; plasmasphere; upstream waves; Van Allen Probes |
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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 have used electric and magnetic measurements by Van Allen Probe B from 2013 to 2014 to examine the equatorial electric drift E \texttimes B/B2 at one field line coordinate set to Arecibo\textquoterights incoherent scatter radar location (L = 1.43). We report on departures from the traditional picture of corotational motion with the Earth in two ways: (1) the rotational angular speed is found to be 10\% smaller than the rotational angular speed of the Earth, in agreement with previous works on plasmaspheric notches, and (2 ... Published by: Geophysical Research Letters Published on: 07/2016 YEAR: 2016 DOI: 10.1002/2016GL069875 corotation; electric field; Inner radiation belt; Ionosphere; plasmasphere; Van Allen Probes |
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Determination of the Earth\textquoterights plasmapause location from the CE-3 EUVC images The Moon-based Extreme Ultraviolet Camera (EUVC) aboard China\textquoterights Chang\textquoterighte-3 (CE-3) mission has successfully imaged the entire Earth\textquoterights plasmasphere for the first time from the side views on lunar surface. An EUVC image on 21 April 2014 is used in this study to demonstrate the characteristics and configurations of the Moon-based EUV imaging and to illustrate the determination algorithm of the plasmapause locations on the magnetic equator. The plasmapause locations determined from all the ... He, Fei; Zhang, Xiao-Xin; Chen, Bo; Fok, Mei-Ching; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2016 YEAR: 2016 DOI: 10.1002/2015JA021863 Chang\textquoterighte-3; EUV imaging; Plasmapause; plasmasphere; reconstruction |
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We report variations in the propagation of the H+ band ion cyclotron whistlers observed by Van Allen Probe A. Ion cyclotron whistlers are one of the EMIC (electromagnetic ion cyclotron) waves generated by mode conversion from lightning whistlers. Crossover frequency is an important frequency for the ion cyclotron whistlers, which is a function of the variations in the local heavy-ion composition. We surveyed waveform data obtained by the Electric and Magnetic Field Instrument and Integrated Science instrument and found that ... Matsuda, Shoya; Kasahara, Yoshiya; Kletzing, Craig; Published by: Geophysical Research Letters Published on: 01/2016 YEAR: 2016 DOI: 10.1002/2015GL066893 EMIC wave; ion cyclotron whistler; plasmasphere; heavy ions; Van Allen Probes |
| 2015 |
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The power spectrum of the compressional component of magnetic fields observed by the Van Allen Probes spacecraft near the magnetospheric equator in the dayside plasmasphere sometimes exhibits regularly spaced multiple peaks at frequencies below 50 mHz. We show by detailed analysis of events observed on two separate days in early 2014 that the frequencies change smoothly with the radial distance of the spacecraft and appear at or very near the frequencies of the odd harmonics of mutiharmonic toroidal mode standing Alfv\ en wa ... Takahashi, Kazue; Waters, Colin; Glassmeier, Karl-Heinz; Kletzing, Craig; Kurth, William; Smith, Charles; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2015 YEAR: 2015 DOI: 10.1002/2015JA021780 Compressional oscillations; Field line resonance; Pc3-Pc4 band; plasmasphere; Van Allen Probes |
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Simultaneous Pi2 observations by the Van Allen Probes inside and outside the plasmasphere Plasmaspheric virtual resonance (PVR) model has been proposed as one of source mechanisms for low-latitude Pi2 pulsations. Since PVR-associated Pi2 pulsations are not localized inside the plasmasphere, simultaneous multipoint observations inside and outside the plasmasphere require to test the PVR model. Until now, however, there are few studies using simultaneous multisatellite observations inside and outside the plasmasphere for understanding the radial structure of Pi2 pulsation. In this study, we focus on the Pi2 event o ... Ghamry, E.; Kim, K.-H.; Kwon, H.-J.; Lee, D.-H.; Park, J.-S.; Choi, J.; Hyun, K.; Kurth, W.; Kletzing, C.; Wygant, J.; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2015 YEAR: 2015 DOI: 10.1002/2015JA021095 Pi2; plasmasphere; Plasmaspheric virtual resonance; Van Allen Probes |
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Statistical characteristic of EMIC waves: Van Allen Probe observations Utilizing the data from the magnetometer instrument which is a part of the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrument suite onboard the Van Allen Probe A from Sep. 2012 to Apr. 2014, when the apogee of the satellite has passed all the MLT sectors, we obtain the statistical distribution characteristic of EMIC waves in the inner magnetosphere over all local times from L=3 to L=6. Compared with the previous statistical results about EMIC waves, the occurrence rates of EMIC waves dis ... Wang, Dedong; Yuan, Zhigang; Yu, Xiongdong; Deng, Xiaohua; Zhou, Meng; Huang, Shiyong; Li, Haimeng; Wang, Zhenzhen; Qiao, Zheng; Kletzing, C.; Wygant, J.; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2015 YEAR: 2015 DOI: 10.1002/2015JA021089 |
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Using the Van Allen Probes we investigate the enhancement in the large scale duskward convection electric field during the geomagnetic storm (Dst ~ -120 nT) on June 1, 2013 and its role in ring current ion transport and energization, and plasmasphere erosion. During this storm, enhancements of ~1-2 mV/m in the duskward electric field in the co-rotating frame are observed down to L shells as low as ~2.3. A simple model consisting of a dipole magnetic field and constant, azimuthally westward, electric field is used to calculat ... Thaller, S.; Wygant, J.; Dai, L.; Breneman, A.W.; Kersten, K.; Cattell, C.A.; Bonnell, J.W.; Fennell, J.F.; Gkioulidou, Matina; Kletzing, C.A.; De Pascuale, S.; Hospodarsky, G.B.; Bounds, S.; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2015 YEAR: 2015 DOI: 10.1002/2014JA020875 electric field; inner magnetosphere; plasma convection; plasmasphere; ring current; 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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EMIC waves and plasmaspheric and plume density: CRRES results Electromagnetic ion cyclotron (EMIC) waves frequently occur during geomagnetic storms, specifically during the main phase and 3\textendash6 days following the minimum Sym - H value. EMIC waves contribute to the loss of ring current ions and radiation belt MeV electrons. Recent studies have suggested that cold plasma density structures found inside the plasmasphere and plasmaspheric plumes are important for the generation and propagation of EMIC waves. During the CRRES mission, 913 EMIC wave events and 124 geomagnetic storms ... Halford, A.; Fraser, B.; Morley, S.; Published by: Journal of Geophysical Research: Space Physics Published on: 03/2015 YEAR: 2015 DOI: 10.1002/2014JA020338 EMIC waves; Geomagnetic storms; plasmasphere; plasmaspheric plumes |
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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 |
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We report results of a systematic analysis of equatorial noise (EN) emissions which are also known as fast magnetosonic waves. EN occurs in the vicinity of the geomagnetic equator at frequencies between the local proton cyclotron frequency and the lower hybrid frequency. Our analysis is based on the data collected by the Spatio-Temporal Analysis of Field Fluctuations\textendashSpectrum Analyzer instruments on board the four Cluster spacecraft. The data set covers the period from January 2001 to December 2010. We have develop ... a, Hrb\; Santolik, O.; emec, F.; a, Mac\; Cornilleau-Wehrlin, N.; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2015 YEAR: 2015 DOI: 10.1002/2014JA020268 equatorial noise; magnetosonic waves; plasmasphere; Radiation belts |
| 2014 |
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Externally driven plasmaspheric ULF waves observed by the Van Allen Probes We analyze data acquired by the Van Allen Probes on 8 November 2012, during a period of extended low geomagnetic activity, to gain new insight into plasmaspheric ultra-low-frequency (ULF) waves. The waves exhibited strong spectral power in the 5\textendash40 mHzband and included multiharmonic toroidal waves visible up to the 11th harmonic, unprecedented in the plasmasphere. During this wave activity, the interplanetary magnetic field cone angle was small, suggesting that the waves were driven by broadband compressional ULF w ... Takahashi, Kazue; Denton, Richard; Kurth, William; Kletzing, Craig; Wygant, John; Bonnell, John; Dai, Lei; Min, Kyungguk; Smith, Charles; MacDowall, Robert; Published by: Journal of Geophysical Research: Space Physics Published on: 12/2014 YEAR: 2014 DOI: 10.1002/2014JA020373 multispacecraft observation; Van Allen Probes; plasmasphere; ULF waves |
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The pitch angle distribution (PAD) of energetic electrons in the slot region and inner radiation belt received little attention in the past decades due to the lack of quality measurements. Using the state-of-art pitch-angle-resolved data from the Magnetic Electron Ion Spectrometer (MagEIS) instrument onboard the Van Allen Probes, a detailed analysis of 100 s keV electron PADs below L = 4 is performed, in which the PADs is categorized into three types: normal (flux peaking at 90o), cap (exceedingly peaking narrowly around 90o ... Zhao, H.; Li, X.; Blake, J.; Fennell, J.; Claudepierre, S.; Baker, D.; Jaynes, A.; Malaspina, D.; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2014 YEAR: 2014 DOI: 10.1002/2014JA020386 energetic electrons; Inner radiation belt; Pitch angle distribution; plasmasphere; Slot region; Van Allen Probes; Wave-particle interaction |
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