Van Allen Probes Bibliography is from August 2012 through September 2021 Notice:
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Found 29 entries in the Bibliography.
Showing entries from 1 through 29
2021 |
Abstract With Van Allen Probes data, we present the observational support for whistler waves guided by the plasmapause based on a case study and statistical analyses. Due to the combined effects of inhomogeneous magnetic fields and plasma densities, whistler waves near the inner edge of plasmapause (plasmasphere side) will be guided by a HDD-like (HDD, high density duct) density gradient, and tend to have very small wave normal angles (WNAs ≤20°). In contrast, whistler waves around the outer edge of the plasmapause (plasm ... Chen, Rui; Gao, Xinliang; Lu, Quanming; Tsurutani, Bruce; Wang, Shui; Published by: Geophysical Research Letters Published on: 03/2021 YEAR: 2021   DOI: https://doi.org/10.1029/2021GL092652 Plasmapause; whistler wave; ducting effect; inner edge; outer edge; wave normal angle; Van Allen Probes |
Prediction of Dynamic Plasmapause Location Using a Neural Network Abstract As a common boundary layer that distinctly separates the regions of high-density plasmasphere and low-density plasmatrough, the plasmapause is essential to comprehend the dynamics and variability of the inner magnetosphere. Using the machine learning framework Pytorch and high-quality Van Allen Probes data set, we develop a neural network model to predict the global dynamic variation of the plasmapause location, along with the identification of 6537 plasmapause crossing events during the period from 2012 to 2017. To ... Guo, DeYu; Fu, Song; Xiang, Zheng; Ni, Binbin; Guo, YingJie; Feng, Minghang; Guo, JianGuang; Hu, Zejun; Gu, Xudong; Zhu, Jianan; Cao, Xing; Wang, Qi; Published by: Space Weather Published on: 03/2021 YEAR: 2021   DOI: https://doi.org/10.1029/2020SW002622 Plasmapause; neural network; Van Allen Probes; space weather forecast |
Abstract Stable auroral red (SAR) arcs are optical events with dominant 630.0-nm emission caused by low-energy electron heat flux into the topside ionosphere from the inner magnetosphere. SAR arcs are observed at subauroral latitudes and often occur during the recovery phase of magnetic storms and substorms. Past studies concluded that these low-energy electrons were generated in the spatial overlap region between the outer plasmasphere and ring-current ions and suggested that Coulomb collisions between plasmaspheric electro ... Inaba, Yudai; Shiokawa, Kazuo; Oyama, Shin-Ichiro; Otsuka, Yuichi; Connors, Martin; Schofield, Ian; Miyoshi, Yoshizumi; Imajo, Shun; Shinbori, Atsuki; Gololobov, Artem; Kazama, Yoichi; Wang, Shiang-Yu; W. Y. Tam, Sunny; Chang, Tzu-Fang; Wang, Bo-Jhou; Asamura, Kazushi; Yokota, Shoichiro; Kasahara, Satoshi; Keika, Kunihiro; Hori, Tomoaki; Matsuoka, Ayako; Kasahara, Yoshiya; Kumamoto, Atsushi; Matsuda, Shoya; Kasaba, Yasumasa; Tsuchiya, Fuminori; Shoji, Masafumi; Kitahara, Masahiro; Nakamura, Satoko; Shinohara, Iku; Spence, Harlan; Reeves, Geoff; MacDowall, Robert; Smith, Charles; Wygant, John; Bonnell, John; Published by: Journal of Geophysical Research: Space Physics Published on: 03/2021 YEAR: 2021   DOI: https://doi.org/10.1029/2020JA029081 SAR arc; Arase; RBSP; ring current; Non-storm-time substorm; Plasmapause; Van Allen Probes |
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 |
2020 |
Analytical Fast Magnetosonic Wave Model Based on Observations of Van Allen Probe Based on observations of Van Allen Probe-A during the period from 19 September 2012 to 28 February 2016, the relations of the fast magnetosonic (MS) wave amplitude Bw with kp index, the wave normal angle (WNA), and the wave normalized frequency (norF) are presented. Then, we establish an analytical regression model for MS wave amplitude as a function of geomagnetic storm activity (presented by kp index), L-shell (L), magnetic local time (MLT), magnetic latitude (λ), and the characteristics of MS wave, that is, wave norF and ... Yao, Fei; Yuan, Zhigang; Yu, Xiongdong; Wang, Dedong; Ouyang, Zhihai; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2020 YEAR: 2020   DOI: https://doi.org/10.1029/2020JA028527 fast magnetosonic wave; Van Allen Probe; analytical regression model; wave normal angle; Plasmapause; Van Allen Probes |
The Impenetrable Barrier: Suppression of Chorus Wave Growth by VLF Transmitters Rapid radiation belt recovery following storm time depletion involves local acceleration of multi-MeV electrons in nonlinear interactions with VLF chorus waves. Previous studies of an apparent impenetrable barrier at L ~ 2.8 focused on diffusion and precipitation loss mechanisms for an explanation of the sharp reduction of multi-MeV electron fluxes earthward of L ~ 3. Van Allen Probes observations for cases when the plasmasphere is contracted earthward of L ~ 3 indicate that strong coherent signals from VLF transmitter ... Foster, John; Erickson, Philip; Omura, Yoshiharu; Baker, Daniel; Published by: Journal of Geophysical Research: Space Physics Published on: 09/2020 YEAR: 2020   DOI: https://doi.org/10.1029/2020JA027913 Radiation belt; Plasmapause; VLF transmitters; wave-particle interactions; Electron acceleration; nonlinear VLF chorus; Van Allen Probes |
Abstract On 22 December 2015, the two Van Allen Probes observed two sets of electromagnetic ion cyclotron (EMIC) wave bursts during a close conjunction when both Probe A and Probe B were separated by 0.57 to 0.68 RE. The EMIC waves occurred during an active period in the recovery phase of a coronal mass ejection-driven geomagnetic storm. Both spacecraft observed EMIC wave bursts that had similar spatial structure within a 1–2 min time delay. The EMIC waves occurred outside the plasmasphere, within ΔL ≈ 1–2 of the ... Sigsbee, K.; Kletzing, C. A.; Faden, J.; Jaynes, A. N.; Reeves, G.; Jahn, J.-M.; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2020 YEAR: 2020   DOI: 10.1029/2019JA027424 EMIC waves; Plasmapause; Proton Anisotropy; Storm Recovery Phase; Van Allen Probes; pitch angle scattering |
The Relation Between Electron Cyclotron Harmonic Waves and Plasmapause: Case and Statistical Studies Abstract Observationally, electron cyclotron harmonic (ECH) waves are often terminated at the outer boundary of the plasmasphere boundary layer (PBL, i.e., plasmapause). Physics of this empirical relation is not well established. In this study, two categories of ECH waves are shown by their different behaviors near PBL. For Category I, all bands of ECH waves terminate at PBL because the density ratio (nh/nc) between hot and cold electrons decreases dramatically across PBL. For Category II, ECH waves, especially the lower har ... Liu, Xu; Chen, Lunjin; Xia, Zhiyang; Published by: Geophysical Research Letters Published on: 04/2020 YEAR: 2020   DOI: 10.1029/2020GL087365 two types of ECH wave; Plasmapause; instability; excitation and attenuation mechanism; statistical characteristics of two types of ECH wave; Van Allen Probes |
The Effect of Plasma Boundaries on the Dynamic Evolution of Relativistic Radiation Belt Electrons Abstract Understanding the dynamic evolution of relativistic electrons in the Earth s radiation belts during both storm and nonstorm times is a challenging task. The U.S. National Science Foundation s Geospace Environment Modeling (GEM) focus group “Quantitative Assessment of Radiation Belt Modeling” has selected two storm time and two nonstorm time events that occurred during the second year of the Van Allen Probes mission for in-depth study. Here, we perform simulations for these GEM challenge events using the 3D Versa ... Wang, Dedong; Shprits, Yuri; Zhelavskaya, Irina; Effenberger, Frederic; Castillo, Angelica; Drozdov, Alexander; Aseev, Nikita; Cervantes, Sebastian; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2020 YEAR: 2020   DOI: 10.1029/2019JA027422 Radiation belt; simulation; relativistic electrons; magnetopause shadowing; Wave-particle interaction; Plasmapause; Van Allen Probes |
On 22 December 2015, the two Van Allen Probes observed two sets of electromagnetic ion cyclotron (EMIC) wave bursts during a close conjunction when both Probe A and Probe B were separated by 0.57 to 0.68 RE. The EMIC waves occurred during an active period in the recovery phase of a coronal mass ejection-driven geomagnetic storm. Both spacecraft observed EMIC wave bursts that had similar spatial structure within a 1–2 min time delay. The EMIC waves occurred outside the plasmasphere, within ΔL ≈ 1–2 of the plasmapau ... Sigsbee, K.; Kletzing, C. A.; Faden, J.; Jaynes, A. N.; Reeves, G.; Jahn, J.-M.; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2020 YEAR: 2020   DOI: https://doi.org/10.1029/2019JA027424 EMIC waves; Plasmapause; Proton Anisotropy; Storm Recovery Phase; Van Allen Probes; pitch angle scattering |
The Relation Between Electron Cyclotron Harmonic Waves and Plasmapause: Case and Statistical Studies Observationally, electron cyclotron harmonic (ECH) waves are often terminated at the outer boundary of the plasmasphere boundary layer (PBL, i.e., plasmapause). Physics of this empirical relation is not well established. In this study, two categories of ECH waves are shown by their different behaviors near PBL. For Category I, all bands of ECH waves terminate at PBL because the density ratio (nh/nc) between hot and cold electrons decreases dramatically across PBL. For Category II, ECH waves, especially the lower harmonic ban ... Liu, Xu; Chen, Lunjin; Xia, Zhiyang; Published by: Geophysical Research Letters Published on: 04/2020 YEAR: 2020   DOI: https://doi.org/10.1029/2020GL087365 two types of ECH wave; Plasmapause; instability; excitation and attenuation mechanism; statistical characteristics of two types of ECH wave; Van Allen Probes |
The Effect of Plasma Boundaries on the Dynamic Evolution of Relativistic Radiation Belt Electrons Understanding the dynamic evolution of relativistic electrons in the Earth s radiation belts during both storm and nonstorm times is a challenging task. The U.S. National Science Foundation s Geospace Environment Modeling (GEM) focus group “Quantitative Assessment of Radiation Belt Modeling” has selected two storm time and two nonstorm time events that occurred during the second year of the Van Allen Probes mission for in-depth study. Here, we perform simulations for these GEM challenge events using the 3D Versatile Elec ... Wang, Dedong; Shprits, Yuri; Zhelavskaya, Irina; Effenberger, Frederic; Castillo, Angelica; Drozdov, Alexander; Aseev, Nikita; Cervantes, Sebastian; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2020 YEAR: 2020   DOI: https://doi.org/10.1029/2019JA027422 Radiation belt; simulation; relativistic electrons; magnetopause shadowing; Wave-particle interaction; Plasmapause; Van Allen Probes |
The Role of the Dynamic Plasmapause in Outer Radiation Belt Electron Flux Enhancement Abstract The plasmasphere is a highly dynamic toroidal region of cold, dense plasma around Earth. Plasma waves exist both inside and outside this region and can contribute to the loss and acceleration of high energy outer radiation belt electrons. Early observational studies found an apparent correlation on long time scales between the observed inner edge of the outer radiation belt and the modeled innermost plasmapause location. More recent work using high-resolution Van Allen Probes data has found a more complex relationsh ... Bruff, M.; Jaynes, A.; Zhao, H.; Goldstein, J.; Malaspina, D.; Baker, D.; Kanekal, S.; Spence, H.; Reeves, G.; Published by: Geophysical Research Letters Published on: 03/2020 YEAR: 2020   DOI: 10.1029/2020GL086991 Plasmapause; outer radiation belt; Magnetosphere; chorus waves; Van Allen Probes |
2019 |
In this report, the relationship between innermost plasmapause locations (Lpp) and initial electron enhancements during both storm and nonstorm (Dst > -30 nT) periods are examined using data from the Van Allen Probes. The geomagnetic storms are classified into coronal mass ejection (CME)-driven and corotating interaction region (CIR)-driven storms to explore their influences on the initial electron enhancements, respectively. We also study nonstorm time electron enhancements and observe frequent, sudden (within two consecuti ... Khoo, L.-Y.; Li, X.; Zhao, H.; Chu, X.; Xiang, Z.; Zhang, K.; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2019 YEAR: 2019   DOI: 10.1029/2019JA027412 energetic electron enhancements; Plasmapause; Radiation Belt Dynamics; Van Allen Probes |
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 |
Based on the measurements of ~100-keV to 10-MeV electrons from the Magnetic Electron Ion Spectrometer (MagEIS) and Relativistic Electron and Proton Telescope (REPT) on the Van Allen Probes, the radiation belt electron energy spectra characterization and evolution have been investigated systematically. The results show that the majority of radiation belt electron energy spectra can be represented by one of three types of distributions: exponential, power law, and bump-on-tail (BOT). The exponential spectra are generally domin ... Zhao, H.; Johnston, W.R.; Baker, D.N.; Li, X.; Ni, B.; Jaynes, A.N.; Kanekal, S.G.; Blake, J.B.; Claudepierre, S.G.; Reeves, G.D.; Boyd, A.J.; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2019 YEAR: 2019   DOI: 10.1029/2019JA026697 Bump-on-tail energy spectrum; Energy spectrum; Exponential energy spectrum; Plasmapause; Power law energy spectrum; radiation belt electrons; Van Allen Probes |
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 |
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 |
Eigenmodes of the transverse Alfv\ enic resonator at the plasmapause: a Van Allen Probes case study A Pc4 ULF wave was detected at spacecraft B of the Van Allen Probes at the plasmapause. A distinctive feature of this wave is the strong periodical modulation of the wave. It is assumed that this modulation is a beating of oscillations close in frequency: at least two harmonics with frequencies of 15.3 and 13.6 MHz are found. It is shown that these harmonics can be the eigenmodes of the transverse resonator at the local maximum of the Alfv\ en velocity. In addition, the observed wave was in a drift resonance with energetic 8 ... Mager, Pavel; Mikhailova, Olga; Mager, Olga; Klimushkin, Dmitri; Published by: Geophysical Research Letters Published on: 09/2018 YEAR: 2018   DOI: 10.1029/2018GL079596 Magnetosphere; Plasmapause; poloidal Alfven waves; transverse resonator; ULF waves; Van Allen Probes; Wave-particle interaction |
The composition of plasma inside geostationary orbit based on Van Allen Probes observations The composition of the inner magnetosphere is of great importance for determining the plasma pressure, and thus the currents and magnetic field configuration. In this study, we perform a statistical survey of equatorial plasma pressure distributions and investigate the relative contributions of ions and electron with different energies inside of geostationary orbit under two AE levels based on over sixty months of observations from the HOPE and RBSPICE mass spectrometers on board Van Allen Probes. We find that the total and ... Yue, Chao; Bortnik, Jacob; Li, Wen; Ma, Qianli; Gkioulidou, Matina; Reeves, Geoffrey; Wang, Chih-Ping; Thorne, Richard; T. Y. Lui, Anthony; Gerrard, Andrew; Spence, Harlan; Mitchell, Donald; Published by: Journal of Geophysical Research: Space Physics Published on: 07/2018 YEAR: 2018   DOI: 10.1029/2018JA025344 ion composition; plasma pressure; Plasmapause; Van Allen Probes |
The effect of the plasmapause on equatorially radially propagating fast magnetosonic (MS) waves in the Earth\textquoterights dipole magnetic field is studied by using finite difference time domain method. We run 1-D simulation for three different density profiles: (1) no plasmapause, (2) with a plasmapause, and (3) with a plasmapause accompanied with fine-scale density irregularity. We find that (1) without plasmapause the radially inward propagating MS wave can reach ionosphere and continuously propagate to lower altitude i ... Liu, Xu; Chen, Lunjin; Yang, Lixia; Xia, Zhiyang; Malaspina, David; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2018 YEAR: 2018   DOI: 10.1002/2017JA024336 fine-scale density structure; finite difference time domain; magnetosonic wave; Plasmapause; Van Allen Probes |
2017 |
We have studied the spatial location relative to the plasmapause (PP) of the most intense electromagnetic ion cyclotron (EMIC) waves observed on Van Allen Probes A and B during their first full precession in local time. Most of these waves occurred over an L range of from -1 to +2 RE relative to the PP. Very few events occurred only within 0.1 RE of the PP, and events with a width in L of < 0.2 REoccurred both inside and outside the PP. Wave occurrence was always associated with high densities of ring current ions; plasma de ... Tetrick, S.; Engebretson, M.; Posch, J.; Olson, C.; Smith, C.; Denton, R.; Thaller, S.; Wygant, J.; Reeves, G.; MacDonald, E.; Fennell, J.; Published by: Journal of Geophysical Research: Space Physics Published on: 03/2017 YEAR: 2017   DOI: 10.1002/2016JA023392 |
2016 |
The relationship between the plasmapause and outer belt electrons We quantify the spatial relationship between the plasmapause and outer belt electrons for a 5 day period, 15\textendash20 January 2013, by comparing locations of relativistic electron flux peaks to the plasmapause. A peak-finding algorithm is applied to 1.8\textendash7.7 MeV relativistic electron flux data. A plasmapause gradient finder is applied to wave-derived electron number densities >10 cm-3. We identify two outer belts. Outer belt 1 is a stable zone of >3 MeV electrons located 1\textendash2 RE inside the plasmapause. ... Goldstein, J.; Baker, D.; Blake, J.; De Pascuale, S.; Funsten, H.; Jaynes, A.; Jahn, J.-M.; Kletzing, C.; Kurth, W.; Li, W.; Reeves, G.; Spence, H.; Published by: Journal of Geophysical Research: Space Physics Published on: 08/2016 YEAR: 2016   DOI: 10.1002/2016JA023046 Plasmapause; Plasmaspheric Hiss; Radiation belts; simulation; storm-time dropouts; Van Allen Probes |
Van Allen Probes observations during the 17 March 2015 major geomagnetic storm strongly suggest that VLF transmitter-induced waves play an important role in sculpting the earthward extent of outer zone MeV electrons. A magnetically confined bubble of very low frequency (VLF) wave emissions of terrestrial, human-produced origin surrounds the Earth. The outer limit of the VLF bubble closely matches the position of an apparent barrier to the inward extent of multi-MeV radiation belt electrons near 2.8 Earth radii. When the VLF ... Foster, J.; Erickson, P.; Baker, D.; Jaynes, A.; Mishin, E.; Fennel, J.; Li, X.; Henderson, M.; Kanekal, S.; Published by: Journal of Geophysical Research: Space Physics Published on: 06/2016 YEAR: 2016   DOI: 10.1002/jgra.v121.610.1002/2016JA022509 |
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 |
2015 |
It is well known that the plasmapause is influenced by the solar wind and magnetospheric conditions. Empirical models of its location have been previously developed such as those by O\textquoterightBrien and Moldwin (2003) and Larsen et al. (2006). In this study, we identified the locations of the plasmapause using the plasma density data obtained from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites. We used the data for the period (2008\textendash2012) corresponding to the ascendi ... Cho, Junghee; Lee, Dae-Young; Kim, Jin-Hee; Shin, Dae-Kyu; Kim, Kyung-Chan; Turner, Drew; Published by: Journal of Geophysical Research: Space Physics Published on: 04/2015 YEAR: 2015   DOI: 10.1002/2015JA021030 |
2014 |
n this study we investigate the link between precipitating electrons from the Van Allen radiation belts and the dynamical plasmapause. We consider electron precipitation observations from the Polar Orbiting Environmental Satellite (POES) constellation during geomagnetic storms. Superposed epoch analysis is performed on precipitating electron observations for the 13 year period of 1999 to 2012 in two magnetic local time (MLT) sectors, morning and afternoon. We assume that the precipitation is due to wave-particle interactions ... Whittaker, Ian; Clilverd, Mark; Rodger, Craig; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2014 YEAR: 2014   DOI: 10.1002/2014JA020446 |
First observation of rising-tone magnetosonic waves Magnetosonic (MS) waves are linearly polarized emissions confined near the magnetic equator with wave normal angle near 90\textdegree and frequency below the lower hybrid frequency. Such waves, also termed equatorial noise, were traditionally known to be \textquotedbllefttemporally continuous\textquotedblright in their time-frequency spectrogram. Here we show for the first time that MS waves actually have discrete wave elements with rising-tone features in their spectrogram. The frequency sweep rate of MS waves, ~1 Hz/s, is ... Fu, H.; Cao, J.; Zhima, Z.; Khotyaintsev, Y.; Angelopoulos, V.; ik, O.; Omura, Y.; Taubenschuss, U.; Chen, L.; Huang, S; Published by: Geophysical Research Letters Published on: 11/2014 YEAR: 2014   DOI: 10.1002/grl.v41.2110.1002/2014GL061867 discrete; frequency sweep rate; magnetosonic wave; nonlinear wave-particle interaction; Plasmapause; rising tone |
An unusual long-lived relativistic electron enhancement event excited by sequential CMEs An unusual long-lived intense relativistic electron enhancement event from July to August 2004 is examined using data from Fengyun-1, POES, GOES, ACE, the Cluster Mission and geomagnetic indices. During the initial 6 days of this event, the observed fluxes in the outer zone enhanced continuously and their maximum increased from 2.1 \texttimes 102 cm-2\textperiodcenteredsr-1\textperiodcentereds-1 to 3.5 \texttimes 104 cm-2\textperiodcenteredsr-1\textperiodcentereds-1, the region of enhanced fluxes extended from L = 3.5-6.5 to ... Yang, Xiao; Zhu, Guang; Zhang, Xiao; Sun, Yue; Liang, Jin; Wei, Xin; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2014 YEAR: 2014   DOI: 10.1002/2014JA019797 Geomagnetic storm/substorm; Interplanetary magnetic field; Plasmapause; Relativistic electron; Solar wind |
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