Bibliography



Found 64 entries in the Bibliography.


Showing entries from 1 through 50


2019

Remote Detection of Drift Resonance Between Energetic Electrons and Ultralow Frequency Waves: Multisatellite Coordinated Observation by Arase and Van Allen Probes

We report the electron flux modulations without corresponding magnetic fluctuations from unique multipoint satellite observations of the Arase (Exploration of Energization and Radiation in Geospace) and the Van Allen Probe (Radiation Belt Storm Probe [RBSP])-B satellites. On 30 March 2017, both Arase and RBSP-B observed periodic fluctuations in the relativistic electron flux with energies ranging from 500 keV to 2 MeV when they were located near the magnetic equator in the morning and dusk local time sectors, respectively. A ...

Teramoto, M.; Hori, T.; Saito, S.; Miyoshi, Y.; Kurita, S.; Higashio, N.; Matsuoka, A.; Kasahara, Y.; Kasaba, Y.; Takashima, T.; Nomura, R.; e, Nos\; Fujimoto, A.; Tanaka, Y.-M.; Shoji, M.; Tsugawa, Y.; Shinohara, M.; Shinohara, I.; Blake, J.; Fennell, J.F.; Claudepierre, S.G.; Turner, D.; Kletzing, C.; Sormakov, D.; Troshichev, O.;

YEAR: 2019     DOI: 10.1029/2019GL084379

Van Allen Probes

Storm Time Depletions of Multi-MeV Radiation Belt Electrons Observed at Different Pitch Angles

During geomagnetic storms, the rapid depletion of the high-energy (several MeV) outer radiation belt electrons is the result of loss to the interplanetary medium through the magnetopause, outward radial diffusion, and loss to the atmosphere due to wave-particle interactions. We have performed a statistical study of 110 storms using pitch angle resolved electron flux measurements from the Van Allen Probes mission and found that inside of the radiation belt (L* = 3 - 5) the number of storms that result in depletion of electron ...

. Y. Drozdov, A; Aseev, N.; Effenberger, F.; Turner, D.; Saikin, A.; . Y. Shprits, Y;

YEAR: 2019     DOI: 10.1029/2019JA027332

EMIC waves; multi-MeV electrons; Radiation belts; Van Allen Probes

Outer Van Allen Radiation Belt Response to Interacting Interplanetary Coronal Mass Ejections

We study the response of the outer Van Allen radiation belt during an intense magnetic storm on 15\textendash22 February 2014. Four interplanetary coronal mass ejections (ICMEs) arrived at Earth, of which the three last ones were interacting. Using data from the Van Allen Probes, we report the first detailed investigation of electron fluxes from source (tens of kiloelectron volts) to core (megaelectron volts) energies and possible loss and acceleration mechanisms as a response to substructures (shock, sheath and ejecta, and ...

Kilpua, E.; Turner, D.; Jaynes, A.; Hietala, H.; Koskinen, H.; Osmane, A.; Palmroth, M.; Pulkkinen, T.; Vainio, R.; Baker, D.; Claudepierre, S.;

YEAR: 2019     DOI: 10.1029/2018JA026238

interplanetary coronal mass ejections; magnetospheric storm; magnetospheric waves; Outer Belt; Radiation belts; Solar wind; Van Allen Probes

Electron intensity measurements by the Cluster/RAPID/IES instrument in Earth\textquoterights radiation belts and ring current

The Cluster mission, launched in 2000, has produced a large database of electron flux intensity measurements in the Earth\textquoterights magnetosphere by the Research with Adaptive Particle Imaging Detector (RAPID)/ Imaging Electron Spectrometer (IES) instrument. However, due to background contamination of the data with high-energy electrons (<400 keV) and inner-zone protons (230-630 keV) in the radiation belts and ring current, the data have been rarely used for inner-magnetospheric science. The current paper presents two ...

Smirnov, A.; Kronberg, E.; Latallerie, F.; Daly, P.; Aseev, N.; . Y. Shprits, Y; Kellerman, A.; Kasahara, S.; Turner, D.; Taylor, M.;

YEAR: 2019     DOI: 10.1029/2018SW001989

electrons; Radiation belts; Solar Cycle; Space weather; Van Allen Probes

Reply to \textquoterightThe dynamics of Van Allen belts revisited\textquoteright

Mann, I.; Ozeke, L.; Morley, S.; Murphy, K.; Claudepierre, S.; Turner, D.; Baker, D.; Rae, I.; Kale, A.; Milling, D.; Boyd, A.; Spence, H.; Singer, H.; Dimitrakoudis, S.; Daglis, I.; Honary, F.;

YEAR: 2019     DOI: 10.1038/nphys4351

Van Allen Probes

The Response of Earth\textquoterights Electron Radiation Belts to Geomagnetic Storms: Statistics From the Van Allen Probes Era Including Effects From Different Storm Drivers

A statistical study was conducted of Earth\textquoterights radiation belt electron response to geomagnetic storms using NASA\textquoterights Van Allen Probes mission. Data for electrons with energies ranging from 30 keV to 6.3 MeV were included and examined as a function of L-shell, energy, and epoch time during 110 storms with SYM-H <=-50 nT during September 2012 to September 2017 (inclusive). The radiation belt response revealed clear energy and L-shell dependencies, with tens of keV electrons enhanced at all L-shells (2.5 ...

Turner, D.; Kilpua, E.; Hietala, H.; Claudepierre, S.; O\textquoterightBrien, T.; Fennell, J.; Blake, J.; Jaynes, A.; Kanekal, S.; Baker, D.; Spence, H.; Ripoll, J.-F.; Reeves, G.;

YEAR: 2019     DOI: 10.1029/2018JA026066

energetic particles; Geomagnetic storms; inner magnetosphere; Radiation belts; relativistic electrons; Van Allen Probes; wave-particle interactions

A Revised Look at Relativistic Electrons in the Earth\textquoterights Inner Radiation Zone and Slot Region

We describe a new, more accurate procedure for estimating and removing inner zone background contamination from Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) radiation belt measurements. This new procedure is based on the underlying assumption that the primary source of background contamination in the electron measurements at L shells less than three, energetic inner belt protons, is relatively stable. Since a magnetic spectrometer can readily distinguish between foreground electrons and background signals, we ...

Claudepierre, S.; O\textquoterightBrien, T.; Looper, M.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Mazur, J.; Turner, D.; Reeves, G.; Spence, H.;

YEAR: 2019     DOI: 10.1029/2018JA026349

Inner zone; particle detectors; Radiation belt; relativistic electrons; Slot region; Space weather; Van Allen Probes

2018

Observations and Fokker-Planck simulations of the L-shell, energy, and pitch-angle structure of Earth\textquoterights electron radiation belts during quiet times

The evolution of the radiation belts in L-shell (L), energy (E), and equatorial pitch-angle (α0) is analyzed during the calm 11-day interval (March 4 \textendashMarch 15) following the March 1 storm 2013. Magnetic Electron and Ion Spectrometer (MagEIS) observations from Van Allen Probes are interpreted alongside 1D and 3D Fokker-Planck simulations combined with consistent event-driven scattering modeling from whistler mode hiss waves. Three (L, E, α0)-regions persist through 11 days of hiss wave scattering; the pitch-angle ...

Ripoll, -F.; Loridan, V.; Denton, M.; Cunningham, G.; Reeves, G.; ik, O.; Fennell, J.; Turner, D.; . Y. Drozdov, A; Villa, J.; . Y. Shprits, Y; Thaller, S.; Kurth, W.; Kletzing, C.; Henderson, M.; . Y. Ukhorskiy, A;

YEAR: 2018     DOI: 10.1029/2018JA026111

electron lifetime; hiss waves; pitch-angle diffusion coefficient; Radiation belts; Van Allen Probes; wave particle interactions

Diagnosis of ULF Wave-Particle Interactions With Megaelectron Volt Electrons: The Importance of Ultrahigh-Resolution Energy Channels

Electron flux measurements are an important diagnostic for interactions between ultralow-frequency (ULF) waves and relativistic (\~1 MeV) electrons. Since measurements are collected by particle detectors with finite energy channel width, they are affected by a phase mixing process that can obscure these interactions. We demonstrate that ultrahigh-resolution electron measurements from the Magnetic Electron Ion Spectrometer on the Van Allen Probes mission\textemdashobtained using a data product that improves the energy resolut ...

Hartinger, M.; Claudepierre, S.; Turner, D.; Reeves, G.; Breneman, A.; Mann, I.; Peek, T.; Chang, E.; Blake, J.; Fennell, J.; O\textquoterightBrien, T.; Looper, M.;

YEAR: 2018     DOI: 10.1029/2018GL080291

drift resonance; particle detector; Pc5; Radiation belts; ULF wave; Van Allen Probes; Wave-particle interaction

Evidence of Microbursts Observed Near the Equatorial Plane in the Outer Van Allen Radiation Belt

We present the first evidence of electron microbursts observed near the equatorial plane in Earth\textquoterights outer radiation belt. We observed the microbursts on March 31st, 2017 with the Magnetic Electron Ion Spectrometer and RBSP Ion Composition Experiment on the Van Allen Probes. Microburst electrons with kinetic energies of 29-92 keV were scattered over a substantial range of pitch angles, and over time intervals of 150-500 ms. Furthermore, the microbursts arrived without dispersion in energy, indicating that they w ...

Shumko, Mykhaylo; Turner, Drew; O\textquoterightBrien, T.; Claudepierre, Seth; Sample, John; Hartley, D.; Fennell, Joseph; Blake, Bernard; Gkioulidou, Matina; Mitchell, Donald;

YEAR: 2018     DOI: 10.1029/2018GL078451

Van Allen Probes

What Causes Radiation Belt Enhancements: A Survey of the Van Allen Probes Era

We survey radiation belt enhancement events during the Van Allen Probes era to determine what mechanism is the dominant cause of enhancements and where it is most effective. Two primary mechanisms have been proposed: (1) betatron/Fermi acceleration due to the Earthward radial transport of electrons which produces monotonic gradients in phase space density (PSD) and (2) \textquotedblleftlocal acceleration" due to gyro/Landau resonant interaction with electromagnetic waves which produces radially localized, growing peaks in PS ...

Boyd, A.J.; Turner, D.L.; Reeves, G.D.; Spence, H.E.; Baker, D.N.; Blake, J.B.;

YEAR: 2018     DOI: 10.1029/2018GL077699

Local Acceleration; Phase space density; Radiation belt; THEMIS; Van Allen Probes

Energetic electron injections deep into the inner magnetosphere: a result of the subauroral polarization stream (SAPS) potential drop

It has been reported that the dynamics of energetic (tens to hundreds of keV) electrons and ions is inconsistent with the theoretical picture in which the large-scale electric field is a superposition of corotation and convection electric fields. Combining one year of measurements by the Super Dual Auroral Radar Network, DMSP F-18 and the Van Allen Probes, we show that subauroral polarization streams are observed when energetic electrons have penetrated below L = 4. Outside the plasmasphere in the premidnight region, potenti ...

Lejosne, ène; Kunduri, B.; Mozer, F.; Turner, D.;

YEAR: 2018     DOI: 10.1029/2018GL077969

adiabatic invariants; drift paths; electric fields; injections; SAPS; Van Allen Probes

The global statistical response of the outer radiation belt during geomagnetic storms

Using the total radiation belt electron content calculated from Van Allen Probe phase space density (PSD), the time-dependent and global response of the outer radiation belt during storms is statistically studied. Using PSD reduces the impacts of adiabatic changes in the main phase, allowing a separation of adiabatic and non-adiabatic effects, and revealing a clear modality and repeatable sequence of events in storm-time radiation belt electron dynamics. This sequence exhibits an important first adiabatic invariant (μ) depe ...

Murphy, Kyle; Watt, C.; Mann, Ian; Rae, Jonathan; Sibeck, David; Boyd, A.; Forsyth, C.; Turner, D.; Claudepierre, S.; Baker, D.; Spence, H.; Reeves, G.; Blake, J.; Fennell, J.;

YEAR: 2018     DOI: 10.1002/2017GL076674

Geomagnetic storms; magnetospheric dynamics; Radiation belts; Solar Wind-Magnetosphere Coupling; statistical analysis; Van Allen Probes

2017

Observations Directly Linking Relativistic Electron Microbursts to Whistler Mode Chorus: Van Allen Probes and FIREBIRD II

We present observations that provide the strongest evidence yet that discrete whistler mode chorus packets cause relativistic electron microbursts. On 20 January 2016 near 1944 UT the low Earth orbiting CubeSat Focused Investigations of Relativistic Electron Bursts: Intensity, Range, and Dynamics (FIREBIRD II) observed energetic microbursts (near L = 5.6 and MLT = 10.5) from its lower limit of 220 keV, to 1 MeV. In the outer radiation belt and magnetically conjugate, Van Allen Probe A observed rising-tone, lower band chorus ...

Breneman, A.; Crew, A.; Sample, J.; Klumpar, D.; Johnson, A.; Agapitov, O.; Shumko, M.; Turner, D.; Santolik, O.; Wygant, J.; Cattell, C.; Thaller, S.; Blake, B.; Spence, H.; Kletzing, C.;

YEAR: 2017     DOI: 10.1002/2017GL075001

Chorus; conjunction; FIREBIRD; microburst; Van Allen Probes

Van Allen Probes measurements of energetic particle deep penetration into the low L region (L<4) during the storm on 8 April 2016

Using measurements from the Van Allen Probes, a penetration event of 10s \textendash 100s of keV electrons and 10s of keV protons into the low L-shells (L<4) is studied. Timing and magnetic local time (MLT) differences of energetic particle deep penetration are unveiled and underlying physical processes are examined. During this event, both proton and electron penetrations are MLT-asymmetric. The observed MLT difference of proton penetration is consistent with convection of plasma sheet protons, suggesting enhanced convectio ...

Zhao, H.; Baker, D.; Califf, S.; Li, X.; Jaynes, A.; Leonard, T.; Kanekal, S.; Blake, J.; Fennell, J.; Claudepierre, S.; Turner, D.; Reeves, G.; Spence, H.;

YEAR: 2017     DOI: 10.1002/2017JA024558

Examining coherency scales, substructure, and propagation of whistler-mode chorus elements with Magnetospheric Multiscale (MMS)

Whistler-mode chorus waves are a naturally occurring electromagnetic emission observed in Earth\textquoterights magnetosphere. Here, for the first time, data from NASA\textquoterights Magnetospheric Multiscale (MMS) mission were used to analyze chorus waves in detail, including the calculation of chorus wave normal vectors, k. A case study was examined from a period of substorm activity around the time of a conjunction between the MMS constellation and NASA\textquoterights Van Allen Probes mission on 07 April 2016. Chorus wa ...

Turner, D.; Lee, J.; Claudepierre, S.; Fennell, J.; Blake, J.; Jaynes, A.; Leonard, T.; Wilder, F.; Ergun, R.; Baker, D.; Cohen, I.; Mauk, B.; Strangeway, R.; Hartley, D.; Kletzing, C.; Breuillard, H.; Le Contel, O.; Khotyaintsev, Yu; Torbert, R.; Allen, R.; Burch, J.; Santolik, O.;

YEAR: 2017     DOI: 10.1002/2017JA024474

chorus waves; inner magnetosphere; Magnetospheric multiscale; MMS; Radiation belts; Van Allen Probes

Lower-hybrid drift waves and electromagnetic electron space-phase holes associated with dipolarization fronts and field-aligned currents observed by the Magnetospheric Multiscale mission during a substorm

We analyse two ion scale dipolarization fronts associated with field-aligned currents detected by the Magnetospheric Multiscale mission during a large substorm on August 10, 2016. The first event corresponds to a fast dawnward flow with an anti-parallel current and could be generated by the wake of a previous fast earthward flow. It is associated with intense lower-hybrid drift waves detected at the front and propagating dawnward with a perpendicular phase speed close to the electric drift and the ion thermal velocity. The s ...

Contel, O.; Nakamura, R.; Breuillard, H.; Argall, M.; Graham, D.; Fischer, D.; o, A.; Berthomier, M.; Pottelette, R.; Mirioni, L.; Chust, T.; Wilder, F.; Gershman, D.; Varsani, A.; Lindqvist, P.-A.; Khotyaintsev, Yu.; Norgren, C.; Ergun, R.; Goodrich, K.; Burch, J.; Torbert, R.; Needell, J.; Chutter, M.; Rau, D.; Dors, I.; Russell, C.; Magnes, W.; Strangeway, R.; Bromund, K.; . Y. Wei, H; Plaschke, F.; Anderson, B.; Le, G.; Moore, T.; Giles, B.; Paterson, W.; Pollock, C.; Dorelli, J.; Avanov, L.; Saito, Y.; Lavraud, B.; Fuselier, S.; Mauk, B.; Cohen, I.; Turner, D.; Fennell, J.; Leonard, T.; Jaynes, A.;

YEAR: 2017     DOI: 10.1002/2017JA024550

dipolarization front; electron hole; fast flow:Van allen Probes; Field-Aligned Current; lower-hybrid drift wave; substorm

Multipoint observations of energetic particle injections and substorm activity during a conjunction between Magnetospheric Multiscale (MMS) and Van Allen Probes

This study examines multipoint observations during a conjunction between MMS and Van Allen Probes on 07 April 2016 in which a series of energetic particle injections occurred. With complementary data from THEMIS, Geotail, and LANL-GEO (16 spacecraft in total), we develop new insights on the nature of energetic particle injections associated with substorm activity. Despite this case involving only weak substorm activity (max. AE < 300 nT) during quiet geomagnetic conditions in steady, below-average solar wind, a complex serie ...

Turner, D.; Fennell, J.; Blake, J.; Claudepierre, S.; Clemmons, J.; Jaynes, A.; Leonard, T.; Baker, D.; Cohen, I.; Gkioulidou, M.; . Y. Ukhorskiy, A; Mauk, B.; Gabrielse, C.; Angelopoulos, V.; Strangeway, R.; Kletzing, C.; Le Contel, O.; Spence, H.; Torbert, R.; Burch, J.; Reeves, G.;

YEAR: 2017     DOI: 10.1002/2017JA024554

energetic particles; injections; inner magnetosphere; plasma sheet; substorms; Van Allen Probes; wave-particle interactions

Diffusive transport of several hundred keV electrons in the Earth\textquoterights slot region

We investigate the gradual diffusion of energetic electrons from the inner edge of the outer radiation belt into the slot region. The Van Allen Probes observed slow inward diffusion and decay of ~200-600 keV electrons following the intense geomagnetic storm that occurred on 17 March 2013. During the 10-day non-disturbed period following the storm, the peak of electron fluxes gradually moved from L~2.7 to L~2.4, and the flux levels decreased by a factor of ~2-4 depending on the electron energy. We simulated the radial intrusi ...

Ma, Q.; Li, W.; Thorne, R.; Bortnik, J.; Reeves, G.; Spence, H.; Turner, D.; Blake, J.; Fennell, J.; Claudepierre, S.; Kletzing, C.; Kurth, W.; Hospodarsky, G.; Baker, D.;

YEAR: 2017     DOI: 10.1002/2017JA024452

Electron transport; Energetic electron diffusion; pitch angle scattering; Slot region dynamics; Van Allen Probes; Van Allen Probes observation; Waves in plasmasphere

Dominance of high energy (>150 keV) heavy ion intensities in Earth\textquoterights middle to outer magnetosphere

Previous observations have driven the prevailing assumption in the field that energetic ions measured by an instrument using a bare solid state detector (SSD) are predominantly protons. However, new near-equatorial energetic particle observations obtained between 7 and 12 RE during Phase 1 of the Magnetospheric Multiscale (MMS) mission challenge the validity of this assumption. In particular, measurements by the Energetic Ion Spectrometer (EIS) instruments have revealed that the intensities of heavy ion species (specifically ...

Cohen, Ian; Mitchell, Donald; Kistler, Lynn; Mauk, Barry; Anderson, Brian; Westlake, Joseph; Ohtani, Shinichi; Hamilton, Douglas; Turner, Drew; Blake, Bern; Fennell, Joseph; Jaynes, Allison; Leonard, Trevor; Gerrard, Andrew; Lanzerotti, Louis; Allen, Robert; Burch, James;

YEAR: 2017     DOI: 10.1002/2017JA024351

energetic ion composition; magnetospheric ion composition; Magnetospheric Multiscale (MMS); outer magnetosphere; ring current composition; suprathermal ions; Van Allen Probes

ULF Wave Analysis and Radial Diffusion Calculation Using a Global MHD Model for the 17 March 2013 and 2015 Storms

The 17 March 2015 St. Patrick\textquoterights Day Storm is the largest geomagnetic storm to date of Solar Cycle 24, with a Dst of -223 nT. The magnetopause moved inside geosynchronous orbit under high solar wind dynamic pressure and strong southward IMF Bz causing loss, however a subsequent drop in pressure allowed for rapid rebuilding of the radiation belts. The 17 March 2013 storm also shows similar effects on outer zone electrons: first a rapid dropout due to inward motion of the magnetopause followed by rapid increase in ...

Li, Zhao; Hudson, Mary; Patel, Maulik; Wiltberger, Michael; Boyd, Alex; Turner, Drew;

YEAR: 2017     DOI: 10.1002/2016JA023846

March 2013; March 2015; radial diffusion; Radiation belt; Van Allen Probes

Effects of whistler mode hiss waves in March 2013

We present simulations of the loss of radiation belt electrons by resonant pitch angle diffusion caused by whistler mode hiss waves for March 2013. Pitch angle diffusion coefficients are computed from the wave properties and the ambient plasma data obtained by the Van Allen Probes with a resolution of 8 hours and 0.1 L-shell. Loss rates follow a complex dynamic structure, imposed by the wave and plasma properties. Hiss effects can be strong, with minimum lifetimes (of ~1 day) moving from energies of ~100 keV at L~5 up to ~2 ...

Ripoll, J.-F.; Santol?k, O.; Reeves, G.; Kurth, W.; Denton, M.; Loridan, V.; Thaller, S.; Kletzing, C.; Turner, D.;

YEAR: 2017     DOI: 10.1002/2017JA024139

diffusion coefficients; electron lifetimes; energy-structure; Radiation belts; Van Allen Probes; Whistler-mode hiss

Spatial Scale and Duration of One Microburst Region on 13 August 2015

Prior studies of microburst precipitation have largely relied on estimates of the spatial scale and temporal duration of the microburst region in order to determine the radiation belt loss rate of relativistic electrons. These estimates have often relied on the statistical distribution of microburst events. However, few studies have directly observed the spatial and temporal evolution of a single microburst event. In this study, we combine BARREL balloon-borne X-ray measurements with FIREBIRD-II and AeroCube-6 CubeSat electr ...

Anderson, B.; Shekhar, S.; Millan, R.; Crew, A.; Spence, H.; Klumpar, D.; Blake, J.; O\textquoterightBrien, T.; Turner, D.;

YEAR: 2017     DOI: 10.1002/2016JA023752

Microbursts; Radiation Belt Dynamics; Van Allen Probes; whistler mode chorus waves

The hidden dynamics of relativistic electrons (0.7-1.5~MeV) in the inner zone and slot region

We present measurements of relativistic electrons (0.7\textendash1.5 MeV) in the inner zone and slot region obtained by the Magnetic Electron and Ion Spectrometer (MagEIS) instrument on Van Allen Probes. The data presented are corrected for background contamination, which is primarily due to inner-belt protons in these low-L regions. We find that \~1 MeV electrons were transported into the inner zone following the two largest geomagnetic storms of the Van Allen Probes era to date, the March and June 2015 events. As \~1 MeV e ...

Claudepierre, S.; O\textquoterightBrien, T.; Fennell, J.; Blake, J.; Clemmons, J.; Looper, M.; Mazur, J.; Roeder, J.; Turner, D.; Reeves, G.; Spence, H.;

YEAR: 2017     DOI: 10.1002/2016JA023719

Inner zone; particle detectors; Radiation belt; relativistic electrons; Slot region; Space weather; Van Allen Probes

The hidden dynamics of relativistic electrons (0.7-1.5~MeV) in the inner zone and slot region

We present measurements of relativistic electrons (0.7\textendash1.5 MeV) in the inner zone and slot region obtained by the Magnetic Electron and Ion Spectrometer (MagEIS) instrument on Van Allen Probes. The data presented are corrected for background contamination, which is primarily due to inner-belt protons in these low-L regions. We find that \~1 MeV electrons were transported into the inner zone following the two largest geomagnetic storms of the Van Allen Probes era to date, the March and June 2015 events. As \~1 MeV e ...

Claudepierre, S.; O\textquoterightBrien, T.; Fennell, J.; Blake, J.; Clemmons, J.; Looper, M.; Mazur, J.; Roeder, J.; Turner, D.; Reeves, G.; Spence, H.;

YEAR: 2017     DOI: 10.1002/2016JA023719

Inner zone; particle detectors; Radiation belt; relativistic electrons; Slot region; Space weather; Van Allen Probes

Simultaneous event-specific estimates of transport, loss, and source rates for relativistic outer radiation belt electrons

The most significant unknown regarding relativistic electrons in Earth\textquoterights outer Van Allen radiation belt is the relative contribution of loss, transport, and acceleration processes within the inner magnetosphere. Detangling each individual process is critical to improve the understanding of radiation belt dynamics, but determining a single component is challenging due to sparse measurements in diverse spatial and temporal regimes. However, there are currently an unprecedented number of spacecraft taking measurem ...

Schiller, Q.; Tu, W.; Ali, A.; Li, X.; Godinez, H.; Turner, D.; Morley, S.; Henderson, M.;

YEAR: 2017     DOI: 10.1002/2016JA023093

CubeSat; data assimilation; electron; event specific; Modeling; Radiation belt; Van Allen Probes

Comparing and contrasting dispersionless injections at geosynchronous orbit during a substorm event

Particle injections in the magnetosphere transport electrons and ions from the magnetotail to the radiation belts. Here we consider generation mechanisms of \textquotedblleftdispersionless\textquotedblright injections, namely, those with simultaneous increase of the particle flux over a wide energy range. In this study we take advantage of multisatellite observations which simultaneously monitor Earth\textquoterights magnetospheric dynamics from the tail toward the radiation belts during a substorm event. Dispersionless inje ...

Kronberg, E.; Grigorenko, E.; Turner, D.; Daly, P.; Khotyaintsev, Y.; Kozak, L.;

YEAR: 2017     DOI: 10.1002/2016JA023551

Acceleration; current wedge; Dipolarization; particle injections; substorm; ULF waves; Van Allen Probes

Investigating the source of near-relativistic and relativistic electrons in Earth\textquoterights inner radiation belt

Using observations from NASA\textquoterights Van Allen Probes, we study the role of sudden particle enhancements at low L shells (SPELLS) as a source of inner radiation belt electrons. SPELLS events are characterized by electron intensity enhancements of approximately an order of magnitude or more in less than 1 day at L < 3. During quiet and average geomagnetic conditions, the phase space density radial distributions for fixed first and second adiabatic invariants are peaked at 2 < L < 3 for electrons ranging in energy from ...

Turner, D.; O\textquoterightBrien, T.; Fennell, J.; Claudepierre, S.; Blake, J.; Jaynes, A.; Baker, D.; Kaneka, S.; Gkioulidou, M.; Henderson, M.; Reeves, G.;

YEAR: 2017     DOI: 10.1029/1999JA900445

energetic particle injections; inner magnetosphere; Radiation belts; relativistic electrons; Van Allen Probes

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.;

YEAR: 2017     DOI: 10.1002/2016JA023047

plasmasphere; Van Allen Probes

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.;

YEAR: 2017     DOI: 10.1002/jgra.v122.110.1002/2016JA023047

plasmasphere; Van Allen Probes

2016

Investigating the source of near-relativistic and relativistic electrons in Earth\textquoterights inner radiation belt

Using observations from NASA\textquoterights Van Allen Probes, we study the role of sudden particle enhancements at low L-shells (SPELLS) as a source of inner radiation belt electrons. SPELLS events are characterized by electron intensity enhancements of approximately an order of magnitude or more in less than one day at L < 3. During quiet and average geomagnetic conditions, the phase space density radial distributions for fixed first and second adiabatic invariants are peaked at 2 < L < 3 for electrons ranging in energy fr ...

Turner, D.; O\textquoterightBrien, T.; Fennell, J.; Claudepierre, S.; Blake, J.; Jaynes, A.; Baker, D.; Kanekal, S.; Gkioulidou, M.; Henderson, M.; Reeves, G.;

YEAR: 2016     DOI: 10.1002/2016JA023600

2720 Energetic Particles; trapped; 2730 Magnetosphere: inner; 2774 Radiation belts; 7807 Charged particle motion and acceleration; 7984 Space radiation environment; energetic particle injections; inner magnetosphere; Radiation belts; relativistic electrons; Van Allen Probes

Energy limits of electron acceleration in the plasma sheet during substorms: A case study with the Magnetospheric Multiscale (MMS) mission

We present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASA\textquoterights Magnetospheric Multiscale mission with a focus on electron acceleration. From a case study during a substorm on 02 August 2015, we find that electrons are only accelerated over a finite energy range, from a lower energy threshold at ~7\textendash9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, electron fluxes decrease, potentially ...

Turner, D.; Fennell, J.; Blake, J.; Clemmons, J.; Mauk, B.; Cohen, I.; Jaynes, A.; Craft, J.; Wilder, F.; Baker, D.; Reeves, G.; Gershman, D.; Avanov, L.; Dorelli, J.; Giles, B.; Pollock, C.; Schmid, D.; Nakamura, R.; Strangeway, R.; Russell, C.; Artemyev, A.; Runov, A.; Angelopoulos, V.; Spence, H.; Torbert, R.; Burch, J.;

YEAR: 2016     DOI: 10.1002/2016GL069691

energetic particle injections; magnetotail; Particle acceleration; plasma sheet; reconnection; substorm; Van Allen Probes

Prompt acceleration of magnetospheric electrons to ultrarelativistic energies by the 17 March 2015 interplanetary shock

Trapped electrons in Earth\textquoterights outer Van Allen radiation belt are influenced profoundly by solar phenomena such as high-speed solar wind streams, coronal mass ejections (CME), and interplanetary (IP) shocks. In particular, strong IP shocks compress the magnetosphere suddenly and result in rapid energization of electrons within minutes. It is believed that the electric fields induced by the rapid change in the geomagnetic field are responsible for the energization. During the latter part of March 2015, a CME impac ...

Kanekal, S.; Baker, D.; Fennell, J.; Jones, A.; Schiller, Q.; Richardson, I.; Li, X.; Turner, D.; Califf, S.; Claudepierre, S.; Wilson, L.; Jaynes, A.; Blake, J.; Reeves, G.; Spence, H.; Kletzing, C.; Wygant, J.;

YEAR: 2016     DOI: 10.1002/2016JA022596

electron; energizaiton; IP shock; ultrarelativsti; Van Allen Probes

Storm time impulsive enhancements of energetic oxygen due to adiabatic acceleration of preexisting warm oxygen in the inner magnetosphere

We examine enhancements of energetic (>50 keV) oxygen ions observed by the Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instrument on board the Van Allen Probes spacecraft in the inner magnetosphere (L ~ 6) at 22\textendash23 h magnetic local time (MLT) during an injection event of the 6 June 2013 storm. Simultaneous observations by two Van Allen Probes spacecraft located close together (~0.5 RE) indicate that particle injections occurred in the premidnight sector (< ~24 h MLT). We also examine the evolut ...

Keika, Kunihiro; Seki, Kanako; e, Masahito; Machida, Shinobu; Miyoshi, Yoshizumi; Lanzerotti, Louis; Mitchell, Donald; Gkioulidou, Matina; Turner, Drew; Spence, Harlan; Larsen, Brian;

YEAR: 2016     DOI: 10.1002/2016JA022384

adiabatic transport from the plasma sheet; oxygen ions of ionospheric origin; preconditions of magnetic storms; preexisting oxygen ions trapped in the inner magnetosphere; Van Allen Probes; Van Allen Probes RBSPICE observations

Global ULF wave analysis of radial diffusion coefficients using a global MHD model for the 17 March 2015 storm

The 17\textendash18 March 2015 storm is the largest geomagnetic storm in the Van Allen Probes era to date. The Lyon-Fedder-Mobarry global MHD model has been run for this event using ARTEMIS data as solar wind input. The ULF wave power spectral density of the azimuthal electric field and compressional magnetic field is analyzed in the 0.5\textendash8.3 mHz range. The lowest three azimuthal modes account for 70\% of the total power during quiet times. However, during high activity, they are not exclusively dominant. The calcul ...

Li, Zhao; Hudson, Mary; Paral, Jan; Wiltberger, Michael; Turner, Drew;

YEAR: 2016     DOI: 10.1002/2016JA022508

March 2015; radial diffusion; radial diffusion coefficient; Radiation belt; ULF waves; Van Allen Probes

Inner zone and slot electron radial diffusion revisited

Using recent data from NASA\textquoterights Van Allen Probes, we estimate the quiet time radial diffusion coefficients for electrons in the inner radiation belt (L < 3) with energies from ~50 to 750 keV. The observations are consistent with dynamics dominated by pitch angle scattering and radial diffusion. We use a coordinate system in which these two modes of diffusion are separable. Then we integrate phase space density over pitch angle to obtain a \textquotedblleftbundle content\textquotedblright that is invariant to pitc ...

O\textquoterightBrien, T.; Claudepierre, S.; Guild, T.; Fennell, J.; Turner, D.; Blake, J.; Clemmons, J.; Roeder, J.;

YEAR: 2016     DOI: 10.1002/2016GL069749

Inner zone; radial diffusion; Radiation belt; Van Allen Probes

Statistical Properties of the Radiation Belt Seed Population

We present a statistical analysis of phase space density data from the first 26 months of the Van Allen Probes mission. In particular we investigate the relationship between the 10s-100s keV seed electrons and >1 MeV core radiation belt electron population. Using a cross correlation analysis, we find that the seed and core populations are well correlated with a coefficient of ≈ 0.73 with a time lag of 10-15 hours. We present evidence of a seed population threshold that is necessary for subsequent acceleration. The depth of ...

Boyd, A.J.; Spence, H.E.; Huang, C.-L.; Reeves, G.; Baker, D.; Turner, D.L.; Claudepierre, S.; Fennell, J.; Blake, J.; Shprits, Y.Y.;

YEAR: 2016     DOI: 10.1002/2016JA022652

Phase space density; Radiation belt; seed population; Van Allen Probes

Explaining the dynamics of the ultra-relativistic third Van Allen radiation belt

Since the discovery of the Van Allen radiation belts over 50 years ago, an explanation for their complete dynamics has remained elusive. Especially challenging is understanding the recently discovered ultra-relativistic third electron radiation belt. Current theory asserts that loss in the heart of the outer belt, essential to the formation of the third belt, must be controlled by high-frequency plasma wave\textendashparticle scattering into the atmosphere, via whistler mode chorus, plasmaspheric hiss, or electromagnetic ion ...

Mann, I.; Ozeke, L.; Murphy, K.; Claudepierre, S.; Turner, D.; Baker, D.; Rae, I.; Kale, A.; Milling, D.; Boyd, A.; Spence, H.; Reeves, G.; Singer, H.; Dimitrakoudis, S.; Daglis, I.; Honary, F.;

YEAR: 2016     DOI: 10.1038/nphys3799

Astrophysical plasmas; Magnetospheric physics; Van Allen Probes

A telescopic and microscopic examination of acceleration in the June 2015 geomagnetic storm: Magnetospheric Multiscale and Van Allen Probes study of substorm particle injection

An active storm period in June 2015 showed that particle injection events seen sequentially by the four (Magnetospheric Multiscale) MMS spacecraft subsequently fed the enhancement of the outer radiation belt observed by Van Allen Probes mission sensors. Several episodes of significant southward interplanetary magnetic field along with a period of high solar wind speed (Vsw ≳ 500 km/s) on 22 June occurred following strong interplanetary shock wave impacts on the magnetosphere. Key events on 22 June 2015 show that the magnet ...

Baker, D.; Jaynes, A.; Turner, D.; Nakamura, R.; Schmid, D.; Mauk, B.; Cohen, I.; Fennell, J.; Blake, J.; Strangeway, R.; Russell, C.; Torbert, R.; Dorelli, J.; Gershman, D.; Giles, B.; Burch, J.;

YEAR: 2016     DOI: 10.1002/grl.v43.1210.1002/2016GL069643

Magnetic reconnection; magnetospheres; Radiation belts; substorms; Van Allen Probes

Reproducing the observed energy-dependent structure of Earth's electron radiation belts during storm recovery with an event-specific diffusion model

We present dynamic simulations of energy-dependent losses in the radiation belt " slot region" and the formation of the two-belt structure for the quiet days after the March 1st storm. The simulations combine radial diffusion with a realistic scattering model, based data-driven spatially and temporally-resolved whistler mode hiss wave observations from the Van Allen Probes satellites. The simulations reproduce Van Allen Probes observations for all energies and L-shells (2 to 6) including (a) the strong energy-dependence to t ...

Ripoll, J.; Reeves, G.; Cunningham, G.; Loridan, V.; Denton, M.; ik, O.; Kurth, W.; Kletzing, C.; Turner, D.; Henderson, M.; . Y. Ukhorskiy, A;

YEAR: 2016     DOI: 10.1002/2016GL068869

electron lifetimes; electron losses; hiss waves; Radiation belts; Slot region; Van Allen Probes; wave particle interactions

Dipolarizing flux bundles in the cis-geosynchronous magnetosphere: relationship between electric fields and energetic particle injections

Dipolarizing flux bundles (DFBs) are small flux tubes (typically < 3 RE in XGSM and YGSM) in the nightside magnetosphere that have magnetic field more dipolar than the background. Although DFBs are known to accelerate particles, creating energetic particle injections outside geosynchronous orbit (trans-GEO), the nature of the acceleration mechanism and the importance of DFBs in generating injections inside geosynchronous orbit (cis-GEO) are unclear. Our statistical study of cis-GEO DFBs using data from the Van Allen Probes r ...

Liu, Jiang; Angelopoulos, V.; Zhang, Xiao-Jia; Turner, D.; Gabrielse, C.; Runov, A.; Li, Jinxing; Funsten, H.; Spence, H.;

YEAR: 2016     DOI: 10.1002/2015JA021691

dipolarization front; dipolarizing flux bundle; energetic particle injection; geosynchronous orbit; magnetic storm; Particle acceleration

2015

Energy dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions.

We present observations of the radiation belts from the HOPE and MagEIS particle detectors on the Van Allen Probes satellites that illustrate the energy-dependence and L-shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on March 1 in more detail. The observations show: (a) At all L-shells, lower-energy electrons are enhanced more often than higher energies; (b) Events that fill the slot region are more common at lower energies; (c) Enhancements of electrons in the inner ...

Reeves, Geoffrey; Friedel, Reiner; Larsen, Brian; Skoug, Ruth; Funsten, Herbert; Claudepierre, Seth; Fennell, Joseph; Turner, Drew; Denton, Mick; Spence, H.; Blake, Bernard; Baker, D.;

YEAR: 2015     DOI: 10.1002/2015JA021569

Acceleration; energetic particles; Inner zone; Outer Zone; Radiation belts; Slot region; Van Allen Probes

Combined effects of concurrent Pc5 and chorus waves on relativistic electron dynamics

We present electron phase space density (PSD) calculations as well as concurrent Pc5 and chorus wave activity observations during two intense geomagnetic storms caused by interplanetary coronal mass ejections (ICMEs) resulting in contradicting net effect. We show that, during the 17 March 2013 storm, the coincident observation of chorus and relativistic electron enhancements suggests that the prolonged chorus wave activity seems to be responsible for the enhancement of the electron population in the outer radiation belt even ...

Katsavrias, C.; Daglis, I.; Li, W.; Dimitrakoudis, S.; Georgiou, M.; Turner, D.; Papadimitriou, C.;

YEAR: 2015     DOI: 10.5194/angeo-33-1173-2015

Magnetospheric physics

Near-Earth Injection of MeV Electrons associated with Intense Dipolarization Electric Fields: Van Allen Probes observations

Substorms generally inject 10s-100s keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeV electron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the pre-midnight sector at L\~5.5, Van Allen Probes (RBSP)-A observed a large dipolarization electric field (50mV/m) over \~40s and a dispersionless injection of electrons up to \~3 MeV. P ...

Dai, Lei; Wang, Chi; Duan, Suping; He, Zhaohai; Wygant, John; Cattell, Cynthia; Tao, Xin; Su, Zhenpeng; Kletzing, Craig; Baker, Daniel; Li, Xinlin; Malaspina, David; Blake, Bernard; Fennell, Joseph; Claudepierre, Seth; Turner, Drew; Reeves, Geoffrey; Funsten, Herbert; Spence, Harlan; Angelopoulos, Vassilis; Fruehauff, Dennis; Chen, Lunjin; Thaller, Scott; Breneman, Aaron; Tang, Xiangwei;

YEAR: 2015     DOI: 10.1002/2015GL064955

electric fields; radiation belt electrons; substorm dipolarization; substorm injection; Van Allen Probes

The effects of geomagnetic storms on electrons in Earth\textquoterights radiation belts

We use Van Allen Probes data to investigate the responses of 10s of keV to 2 MeV electrons throughout a broad range of the radiation belts (2.5 <= L <= 6.0) during 52 geomagnetic storms from the most recent solar maximum. Electron storm-time responses are highly dependent on both electron energy and L-shell. 10s of keV electrons typically have peak fluxes in the inner belt or near-Earth plasma sheet and fill the inner magnetosphere during storm main phases. ~100 to ~600 keV electrons are enhanced in up to 87\% of cases aroun ...

Turner, D.; O\textquoterightBrien, T.; Fennell, J.; Claudepierre, S.; Blake, J.; Kilpua, E.; Hietala, H.;

YEAR: 2015     DOI: 10.1002/2015GL064747

electrons; Van Allen Probes; Geomagnetic storms; Radiation belts

New model fit functions of the plasmapause location determined using THEMIS observations during the ascending phase of Solar Cycle 24

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

Plasmapause; THEMIS

Unraveling the drivers of the storm time radiation belt response

We present a new framework to study the time evolution and dynamics of the outer Van Allen belt electron fluxes. The framework is entirely based on the large-scale solar wind storm drivers and their substructures. The Van Allen Probe observations, revealing the electron flux behavior throughout the outer belt, are combined with continuous, long-term (over 1.5 solar cycles) geosynchronous orbit data set from GOES and solar wind measurements A superposed epoch analysis, where we normalize the timescales for each substructure ( ...

Kilpua, E.; Hietala, H.; Turner, D.; Koskinen, H.; Pulkkinen, T.; Rodriguez, J.; Reeves, G.; Claudepierre, S.; Spence, H.;

YEAR: 2015     DOI: 10.1002/2015GL063542

coronal mass ejections; Magnetic Storms; Radiation belts; solar wind storm drivers; stream interaction regions; Van Allen Probes

Spatial structure and temporal evolution of energetic particle injections in the inner magnetosphere during the 14 July 2013 substorm event.

Recent results by the Van Allen Probes mission showed that the occurrence of energetic ion injections inside geosynchronous orbit could be very frequent throughout the main phase of a geomagnetic storm. Understanding, therefore, the formation and evolution of energetic particle injections is critical in order to quantify their effect in the inner magnetosphere. We present a case study of a substorm event that occurred during a weak storm (Dst ~ - 40 nT) on 14 July 2013. Van Allen Probe B, inside geosynchronous orbit, observe ...

Gkioulidou, Matina; Ohtani, S.; Mitchell, D.; Ukhorskiy, A.; Reeves, G.; Turner, D.; Gjerloev, J.; e, Nos\; Koga, K.; Rodriguez, J.; Lanzerotti, L.;

YEAR: 2015     DOI: 10.1002/2014JA020872

inner magnetosphere; Van Allen Probes

Energetic electron injections deep into the inner magnetosphere associated with substorm activity

From a survey of the first nightside season of NASA\textquoterights Van Allen Probes mission (Dec/2012 \textendash Sep/2013), 47 energetic (10s to 100s of keV) electron injection events were found at L-shells <= 4, all of which are deeper than any previously reported substorm-related injections. Preliminary details from these events are presented, including how: all occurred shortly after dipolarization signatures and injections were observed at higher L-shells; the deepest observed injection was at L~2.5; and, surprisingly, ...

Turner, D.; Claudepierre, S.; Fennell, J.; O\textquoterightBrien, T.; Blake, J.; Lemon, C.; Gkioulidou, M.; Takahashi, K.; Reeves, G.; Thaller, S.; Breneman, A.; Wygant, J.; Li, W.; Runov, A.; Angelopoulos, V.;

YEAR: 2015     DOI: 10.1002/2015GL063225

energetic particle injections; inner magnetosphere; Radiation belts; substorms; THEMIS; Van Allen Probes

Modeling CME-shock driven storms in 2012 - 2013: MHD-test particle simulations

The Van Allen Probes spacecraft have provided detailed observations of the energetic particles and fields environment for CME-shock driven storms in 2012 to 2013 which have now been modeled with MHD-test particle simulations. The Van Allen Probes orbital plane longitude moved from the dawn sector in 2012 to near midnight and pre-noon for equinoctial storms of 2013, providing particularly good measurements of the inductive electric field response to magnetopause compression for the 8 October 2013 CME-shock driven storm. An ab ...

Hudson, M.; Paral, J.; Kress, B.; Wiltberger, M.; Baker, D.; Foster, J.; Turner, D.; Wygant, J.;

YEAR: 2015     DOI: 10.1002/2014JA020833

Van Allen Probes; CME-shock



  1      2