Found 30 entries in the Bibliography.
Showing entries from 1 through 30
| 2020 |
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Quantifying the Effect of Plasmaspheric Hiss on the Electron Loss from the Slot Region Abstract We present global statistical models of both wave amplitude and wave normal angle (WNA) of plasmaspheric hiss using Van Allen Probe-A observations. They utilize the time history of solar wind parameters, i.e., interplanetary magnetic field BZ and solar wind speed, and the AE index for each measurement of hiss waves as inputs. The solar wind parameter-based model generally results in higher performance than using only the AE index as an input. Both observations and model results reveal a clear dependence of hiss wave ... Kim, Kyung-Chan; Shprits, Yuri; Wang, Dedong; YEAR: 2020 DOI: 10.1029/2019JA027555 Plasmaspheric Hiss; Van Allen Probes; Electron slot region; Statistical modeling; Diffusion simulation; Wave-particle interaction |
| 2019 |
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We report on evidence for the generation of an ultra-low frequency plasma wave by the drift-mirror plasma instability in the dynamic plasma environment of Earth\textquoterights inner magnetosphere. The plasma measurements are obtained from the Radiation Belt Storm Probes Ion Composition Experiment onboard NASA\textquoterights Van Allen Probes Satellites. We show that the measured wave-particle interactions are driven by the drift-mirror instability. Theoretical analysis of the data demonstrates that the drift-mirror mode pla ... Soto-Chavez, A.; Lanzerotti, L.; Manweiler, J.; Gerrard, A.; Cohen, R.; Xia, Z.; Chen, L.; Kim, H.; YEAR: 2019 DOI: 10.1063/1.5083629 |
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Quasi Thermal Noise Spectroscopy for Van Allen Probes Quasi thermal fluctuations in the Langmuir/upper-hybrid frequency range are pervasively observed in space plasmas including the radiation belt and the ring current region of inner magnetosphere as well as the solar wind. The quasi thermal noise spectroscopy may be employed in order to determine the electron density and temperature as well as to diagnose the properties of energetic electrons when direct measurements are not available. However, when employing the technique, one must carefully take the spacecraft orientation in ... Yoon, Peter; Hwang, Junga; Kim, Hyangpyo; Seough, Jungjoon; YEAR: 2019 DOI: 10.1029/2019JA026460 (n+1/2)fce; antenna geometry; Quasi-thermal; Radiation belt; Upper hybrid; Van Allen Probes |
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Statistical Analysis of Hiss Waves in Plasmaspheric Plumes Using Van Allen Probe Observations Plasmaspheric hiss waves commonly observed in high-density regions in the Earth\textquoterights magnetosphere are known to be one of the main contributors to the loss of radiation belt electrons. There has been a lot of effort to investigate the distributions of hiss waves in the plasmasphere, while relatively little attention has been given to those in the plasmaspheric plume. In this study, we present for the first time a statistical analysis of the occurrence and the spatial distribution of wave amplitudes and wave normal ... Kim, Kyung-Chan; Shprits, Yuri; YEAR: 2019 DOI: 10.1029/2018JA026458 |
| 2018 |
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The stimulation of EMIC waves by a magnetospheric compression is perhaps the closest thing to a controlled experiment that is currently possible in magnetospheric physics, in that one prominent factor that can increase wave growth acts at a well-defined time. We present a detailed analysis of EMIC waves observed in the outer dayside magnetosphere by the four Magnetosphere Multiscale (MMS) spacecraft, Van Allen Probe A, and GOES 13, and by four very high latitude ground magnetometer stations in the western hemisphere before, ... Engebretson, M.; Posch, J.; Capman, N.; Campuzano, N.; elik, P.; Allen, R.; Vines, S.; Anderson, B.; Tian, S.; Cattell, C.; Wygant, J.; Fuselier, S.; Argall, M.; Lessard, M.; Torbert, R.; Moldwin, M.; Hartinger, M.; Kim, H.; Russell, C.; Kletzing, C.; Reeves, G.; Singer, H.; YEAR: 2018 DOI: 10.1029/2018JA025984 |
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Anisotropic velocity distributions of protons have long been considered as free energy sources for exciting electromagnetic ion cyclotron (EMIC) waves in the Earth\textquoterights magnetosphere. Here we rigorously calculated the proton anisotropy parameter using proton data obtained from Van Allen Probe-A observations. The calculations are performed for times during EMIC wave events (distinguishing the times immediately after and before EMIC wave onsets) and for times exhibiting no EMIC waves. We find that the anisotropy val ... Noh, Sung-Jun; Lee, Dae-Young; Choi, Cheong-Rim; Kim, Hyomin; Skoug, Ruth; YEAR: 2018 DOI: 10.1029/2018JA025385 EMIC waves; Ion cyclotron instability; RBSP; temperature anisotropy; Van Allen Probes |
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Characteristics of Sudden Commencements Observed by Van Allen Probes in the Inner Magnetosphere We have statistically studied sudden commencement (SC) by using the data acquired from Van Allen Probes (VAP) in the inner magnetosphere (L = 3.0\textendash6.5) and GOES spacecraft at geosynchronous orbit (L =\~ 6.7) from October 2012 to September 2017. During the time period, we identified 85 SCs in the inner magnetosphere and 90 SCs at geosynchronous orbit. Statistical results of the SC events reveal the following characteristics. (1) There is strong seasonal dependence of the geosynchronous SC amplitude in the radial BV c ... Fathy, A.; Kim, K.-H.; Park, J.-S.; Jin, H.; Kletzing, C.; Wygant, J.; Ghamry, E.; YEAR: 2018 DOI: 10.1002/2017JA024770 |
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Space Weather Operation at KASI with Van Allen Probes Beacon Signals The Van Allen Probes (VAPs) are the only modern NASA spacecraft broadcasting real-time data on the Earth\textquoterights radiation belts for space weather operations. Since 2012, the Korea Astronomy and Space Science Institute (KASI) has contributed to the receipt of this data via a 7-m satellite tracking antenna and used these data for space weather operations. An approximately 15-min period is required from measurement to acquisition of Level-1 data. In this paper, we demonstrate the use of VAP data for monitoring space we ... Lee, Jongkil; Kim, Kyung-Chan; Romeo, Giuseppe; Ukhorskiy, Sasha; Sibeck, David; Kessel, Ramona; Mauk, Barry; Giles, Barbara; Gu, Bon-Jun; Lee, Hyesook; Park, Young-Deuk; Lee, Jaejin; YEAR: 2018 DOI: 10.1002/2017SW001726 Electron acceleration; Radiation belt; Relativistic electron; Space weather; Van Allen Probes |
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Survey of the Favorable Conditions for Magnetosonic Wave Excitation The ratio of the proton ring velocity (VR) to the local Alfven speed (VA), in addition to proton ring distributions, plays a key factor in the excitation of magnetosonic waves at frequencies between the proton cyclotron frequency fcp and the lower hybrid resonance frequency fLHR in the Earth\textquoterights magnetosphere. Here we investigate whether there is a statistically significant relationship between occurrences of proton rings and magnetosonic waves both outside and inside the plasmapause using particle and wave data ... Kim, Kyung-Chan; Shprits, Yuri; YEAR: 2018 DOI: 10.1002/2017JA024865 magnetosonic equatorial noise; proton ring distribution; 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; 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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SC-associated electric field variations in the magnetosphere and ionospheric convective flows We examine magnetic and electric field perturbations associated with a sudden commencement (SC), caused by an interplanetary (IP) shock passing over the Earth\textquoterights magnetosphere on 16 February 2013. The SC was identified in the magnetic and electric field data measured at THEMIS-E (THE-E: MLT = 12.4, L = 6.3), Van Allen Probe-A (VAP-A: MLT = 3.2, L = 5.1), and Van Allen Probe-B (VAP-B: MLT = 0.2. L= 4.9) in the magnetosphere. During the SC interval, THE-E observed a dawnward-then-duskward electric (E) field pertur ... Kim, S.-I.; Kim, K.-H.; Kwon, H.-J.; Jin, H.; Lee, E.; Jee, G.; Nishitani, N.; Hori, T.; Lester, M.; Wygant, J.; YEAR: 2017 DOI: 10.1002/2017JA024611 |
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SC-associated electric field variations in the magnetosphere and ionospheric convective flows We examine magnetic and electric field perturbations associated with a sudden commencement (SC), caused by an interplanetary (IP) shock passing over the Earth\textquoterights magnetosphere on 16 February 2013. The SC was identified in the magnetic and electric field data measured at THEMIS-E (THE-E: MLT = 12.4, L = 6.3), Van Allen Probe-A (VAP-A: MLT = 3.2, L = 5.1), and Van Allen Probe-B (VAP-B: MLT = 0.2. L= 4.9) in the magnetosphere. During the SC interval, THE-E observed a dawnward-then-duskward electric (E) field pertur ... Kim, S.-I.; Kim, K.-H.; Kwon, H.-J.; Jin, H.; Lee, E.; Jee, G.; Nishitani, N.; Hori, T.; Lester, M.; Wygant, J.; YEAR: 2017 DOI: 10.1002/2017JA024611 |
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Ring Current He-Ion Control by Bounce Resonant ULF Waves Ring current energy He-ion (\~65 keV to \~520 keV) differential flux data from the Radiation Belt Storm Probe Ion Composition Experiment (RBSPICE) instrument aboard the Van Allan Probes spacecraft show considerable variability during quiet solar wind and geomagnetic time periods. Such variability is apparent from orbit to orbit (\~9 hours) of the spacecraft and is observed to be \~50\textendash100\% of the nominal flux. Using data from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrume ... Kim, Hyomin; Gerrard, Andrew; Lanzerotti, Louis; Soto-Chavez, Rualdo; Cohen, Ross; Manweiler, Jerry; YEAR: 2017 DOI: 10.1002/2017JA023958 bounce resonance; Helium ion; ring current; ULF waves; Van Allen Probes |
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In this paper, using the multisatellite (the Van Allen Probes and two GOES satellites) observations in the inner magnetosphere, we examine two electromagnetic ion cyclotron (EMIC) wave events that are triggered by Pdyn enhancements under prolonged northward interplanetary magnetic field quiet time preconditions. For both events, the impact of enhanced Pdyn causes EMIC waves at multiple points. However, we find a strong spatial dependence that EMIC waves due to enhanced Pdyn impact can occur at multiple points (likely globall ... Cho, J.-H.; Lee, D.-Y.; Noh, S.-J.; Kim, H.; Choi, C.; Lee, J.; Hwang, J.; YEAR: 2017 DOI: 10.1002/2016JA023827 |
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We present the dependence of the magnetosonic wave amplitudes both outside and inside the plasmapause on the solar wind and AE index using Van Allen Probe-A spacecraft during the time period of 1 October 2012 to 31 December 2015, based on a correlation and regression analysis. Solar wind parameters considered are the southward interplanetary magnetic field (IMF BS), solar wind number density (NSW), and bulk speed (VSW). We find that the wave amplitudes outside (inside) the plasmapause are well correlated with the preceding A ... Kim, Kyung-Chan; Shprits, Yuri; YEAR: 2017 DOI: 10.1002/2017JA024094 magnetosonic equatorial noise; solar wind dependence; Van Allen Probes |
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Climatology of high-β plasma measurements in Earth\textquoterights inner magnetosphere Since their launch in August 2012, the Radiation Belt Storm Probe Ion Composition Experiment (RBSPICE) instruments on the NASA Van Allen Probes spacecraft have been making continuous high-resolution measurements of Earth\textquoterights ring current plasma environment. After a full traversal through all magnetic local times, a climatology (i.e., a survey of observations) of high-beta (β) plasma events (defined here as β > 1) as measured by the RBSPICE instrument in the \~45 keV to \~600 keV proton energy range in the inner ... Cohen, Ross; Gerrard, Andrew; Lanzerotti, Louis; Soto-Chavez, A.; Kim, Hyomin; Manweiler, Jerry; YEAR: 2017 DOI: 10.1002/2016JA022513 climatology; high-beta plasma; inner magnetosphere; RBSPICE; Van Allen Probes |
| 2016 |
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Climatology of high β plasma measurements in Earth\textquoterights inner magnetosphere Since their launch in August 2012, the Radiation Belt Storm Probe Ion Composition Experiment (RBSPICE) instruments on the NASA Van Allen Probes spacecraft have been making continuous high resolution measurements of Earth\textquoterights ring current plasma environment. After a full traversal through all magnetic local times, a climatology (i.e., a survey of observations) of high beta (β) plasma events (defined here as β>1) as measured by the RBSPICE instrument in the \~45-keV to \~600-keV proton energy range in the inner m ... Cohen, Ross; Gerrard, Andrew; Lanzerotti, Louis; Soto-Chavez, A.; Kim, Hyomin; Manweiler, Jerry; YEAR: 2016 DOI: 10.1002/2016JA022513 climatology; high beta plasma; inner magnetosphere; RBSPICE; Van Allen Probes |
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A strongly energy-dependent ring current ion loss was measured by the RBSPICE instrument on the Van Allen Probes A spacecraft in the local evening sector during the 17 March 2015 geomagnetic storm. The ion loss is found to be energy dependent where only ions with energies measured above \~ 150 keV have a significant drop in intensity. At these energies the ion dynamics are principally controlled by variations of the geomagnetic field which, during magnetic storms, exhibits large scale variations on timescales from minutes ... Soto-Chavez, A.; Lanzerotti, L.; Gerrard, A.; Kim, H.; Bortnik, J.; Manweiler, J.; YEAR: 2016 DOI: 10.1002/2016JA022512 inner magnetosphere; Magnetic Storms; Ring current ion.; Van Allen Probes |
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Magnetospheric compression due to impact of enhanced solar wind dynamic pressure Pdyn has long been considered as one of the generation mechanisms of electromagnetic ion cyclotron (EMIC) waves. With the Van Allen Probe-A observations, we identify three EMIC wave events that are triggered by Pdyn enhancements under prolonged northward IMF quiet time preconditions. They are in contrast to one another in a few aspects. Event 1 occurs in the middle of continuously increasing Pdyn while Van Allen Probe-A is located outside the pl ... Cho, J.-H.; Lee, D.-Y.; Noh, S.-J.; Shin, D.-K.; Hwang, J.; Kim, K.-C.; Lee, J.; Choi, C.; Thaller, S.; Skoug, R.; YEAR: 2016 DOI: 10.1002/2016JA022841 |
| 2015 |
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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.; YEAR: 2015 DOI: 10.1002/2015JA021095 Pi2; plasmasphere; Plasmaspheric virtual resonance; Van Allen Probes |
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We investigate an electron flux dropout during a weak storm on 7\textendash8 November 2008, with Dst minimum value being -37 nT. During this period, two clear dropouts were observed on GOES 11 > 2 MeV electrons. We also find a simultaneous dropout in the subrelativistic electrons recorded by Time History of Events and Macroscale Interactions during Substorms probes in the outer radiation belt. Using the Radiation Belt Environment model, we try to reproduce the observed dropout features in both relativistic and subrelativisti ... Hwang, J.; Choi, E.-J.; Park, J.-S.; Fok, M.-C.; Lee, D.-Y.; Kim, K.-C.; Shin, D.-K.; Usanova, M.; Reeves, G.; YEAR: 2015 DOI: 10.1002/2015JA021085 atmospheric precipitation; flux dropout; Geomagnetic storm; magneopause shadowing; Radiation belt; RBE model |
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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; YEAR: 2015 DOI: 10.1002/2015JA021030 |
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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; YEAR: 2015 DOI: 10.1002/2015JA021030 |
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Whistler mode chorus waves are considered to play a central role in accelerating and scattering electrons in the outer radiation belt. While in situ measurements are usually limited to the trajectories of a small number of satellites, rigorous theoretical modeling requires a global distribution of chorus wave characteristics. In the present work, by using a large database of chorus wave observations made on the Time History of Events and Macroscale Interactions during Substorms satellites for about 5 years, we develop predic ... Kim, Jin-Hee; Lee, Dae-Young; Cho, Jung-Hee; Shin, Dae-Kyu; Kim, Kyung-Chan; Li, Wen; Kim, Thomas; YEAR: 2015 DOI: 10.1002/2014JA020900 |
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Whistler mode chorus waves are considered to play a central role in accelerating and scattering electrons in the outer radiation belt. While in situ measurements are usually limited to the trajectories of a small number of satellites, rigorous theoretical modeling requires a global distribution of chorus wave characteristics. In the present work, by using a large database of chorus wave observations made on the Time History of Events and Macroscale Interactions during Substorms satellites for about 5 years, we develop predic ... Kim, Jin-Hee; Lee, Dae-Young; Cho, Jung-Hee; Shin, Dae-Kyu; Kim, Kyung-Chan; Li, Wen; Kim, Thomas; YEAR: 2015 DOI: 10.1002/2014JA020900 |
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Whistler mode chorus waves are considered to play a central role in accelerating and scattering electrons in the outer radiation belt. While in situ measurements are usually limited to the trajectories of a small number of satellites, rigorous theoretical modeling requires a global distribution of chorus wave characteristics. In the present work, by using a large database of chorus wave observations made on the Time History of Events and Macroscale Interactions during Substorms satellites for about 5 years, we develop predic ... Kim, Jin-Hee; Lee, Dae-Young; Cho, Jung-Hee; Shin, Dae-Kyu; Kim, Kyung-Chan; Li, Wen; Kim, Thomas; YEAR: 2015 DOI: 10.1002/2014JA020900 |
| 2014 |
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Magnetopause structure favorable for radiation belt electron loss Magnetopause shadowing is regarded as one of the major reasons for the loss of relativistic radiation belt electrons, although this has not yet been fully validated by observations. Previous simulations on this process assumed that all of the electrons encountering the magnetopause are simply lost into the magnetosheath just as ring current ions can be and did not examine details of the particle dynamics across and inside the magnetopause which has a finite thickness. In this paper, we perform test particle orbit calculation ... Kim, Kyung-Chan; Lee, Dae-Young; YEAR: 2014 DOI: 10.1002/2014JA019880 magnetopause shadowing; relativistic electron loss; test particle orbit calculation |
| 2013 |
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Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) The Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) on the two Van Allen Probes spacecraft is the magnetosphere ring current instrument that will provide data for answering the three over-arching questions for the Van Allen Probes Program: RBSPICE will determine \textquotedbllefthow space weather creates the storm-time ring current around Earth, how that ring current supplies and supports the creation of the radiation belt populations,\textquotedblright and how the ring current is involved in radiation belt ... Mitchell, D.; Lanzerotti, L.; Kim, C.; Stokes, M.; Ho, G.; Cooper, S.; UKHORSKIY, A; Manweiler, J.; Jaskulek, S.; Haggerty, D.; Brandt, P.; SITNOV, M; Keika, K.; Hayes, J.; Brown, L.; Gurnee, R.; Hutcheson, J.; Nelson, K.; Paschalidis, N.; Rossano, E.; Kerem, S.; YEAR: 2013 DOI: 10.1007/s11214-013-9965-x |
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Unusual stable trapping of the ultrarelativistic electrons in the Van Allen radiation belts Radiation in space was the first discovery of the space age. Earth\textquoterights radiation belts consist of energetic particles that are trapped by the geomagnetic field and encircle the planet1. The electron radiation belts usually form a two-zone structure with a stable inner zone and a highly variable outer zone, which forms and disappears owing to wave\textendashparticle interactions on the timescale of a day, and is strongly influenced by the very-low-frequency plasma waves. Recent observations revealed a third radiat ... Shprits, Yuri; Subbotin, Dmitriy; Drozdov, Alexander; Usanova, Maria; Kellerman, Adam; Orlova, Ksenia; Baker, Daniel; Turner, Drew; Kim, Kyung-Chan; YEAR: 2013 DOI: 10.1038/nphys2760 |
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Characteristic dimension of electromagnetic ion cyclotron wave activity in the magnetosphere [1] In this paper, we estimate the size of coherent activity of electromagnetic ion cyclotron (EMIC) waves using the multi-spacecraft observations made during the Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission. We calculate the cross-correlations between EMIC wave powers measured by different THEMIS spacecraft, plot them over the separation distances between pairs of observing spacecraft, and determine the 1/e folding distance of the correlations as the characteristic dimension of the co ... Lee, Jeongwoo; Min, Kyungguk; Kim, Kap-Sung; YEAR: 2013 DOI: 10.1002/jgra.50242 |
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