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VLF waves
Authors: Jaynes A.N., Baker D.N., Singer H.J., Rodriguez J.V., Loto'aniu T.M., et al.
Title: Source and Seed Populations for Relativistic Electrons: Their Roles in Radiation Belt Changes
Abstract: Strong enhancements of outer Van Allen belt electrons have been shown to have a clear dependence on solar wind speed and on the duration of southward interplanetary magnetic field. However, individual case study analyses also have demonstrated that many geomagnetic storms produce little in the way of outer belt enhancements and, in fact, may produce substantial losses of relativistic electrons. In this study, focused upon a key period in August-September 2014, we use GOES geostationary orbit electron flux data and Van Allen Probes particle and fields data to study the process of radiation belt electron acceleration. One particular interval, 13-22 September, initiated by a short-lived geomagnetic storm and characterized by a long period of primarily northward IMF, showed strong depletion of. . .
Date: 07/2015 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2015JA021234 Available at: http://doi.wiley.com/10.1002/2015JA021234
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Van Allen Probes
Authors: Zhao H., Baker D.N., Li X, Malaspina D.M., Jaynes A.N., et al.
Title: On the Acceleration Mechanism of Ultrarelativistic Electrons in the Center of the Outer Radiation Belt: A Statistical Study
Abstract: Using energetic particle and wave measurements from the Van Allen Probes, Polar Orbiting Environmental Satellites (POES), and Geostationary Operational Environmental Satellite (GOES), the acceleration mechanism of ultrarelativistic electrons (>3 MeV) in the center of the outer radiation belt is investigated statistically. A superposed epoch analysis is conducted using 19 storms, which caused flux enhancements of 1.8–7.7 MeV electrons. The evolution of electron phase space density radial profile suggests an energy‐dependent acceleration of ultrarelativistic electrons in the outer belt. Especially, for electrons with very high energies (~7 MeV), prevalent positive phase space density radial gradients support inward radial diffusion being responsible for electron acceleration in the cente. . .
Date: 10/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027111 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027111
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Authors: Xu Jiyao, He Zhaohai, Baker D.N., Roth Ilan, Wang C., et al.
Title: Characteristics of high energy proton responses to geomagnetic activities in the inner radiation belt observed by the RBSP satellite
Abstract: High energy trapped particles in the radiation belts constitute potential threats to the functionality of satellites as they enter into those regions. In the inner radiation belt, the characteristics of high‐energy (>20MeV) protons variations during geomagnetic activity times have been studied by implementing four‐year (2013‐2016) observations of the Van Allen probes. An empirical formula has been used to remove the satellite orbit effect, by which proton fluxes have been normalized to the geomagnetic equator. Case studies show that the region of L<1.7 is relatively stable, while L>1.7 is more dynamic and the most significant variation of proton fluxes occurs at L=2.0. The four‐year survey at L=2.0 indicates that for every geomagnetic storm, sharp descent in proton fluxes is accomp. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2018JA026205 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026205
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Authors: Jaynes A.N., Baker D.N., Singer H.J., Rodriguez J.V., Loto'aniu T.M., et al.
Title: Source and Seed Populations for Relativistic Electrons: Their Roles in Radiation Belt Changes
Abstract: Strong enhancements of outer Van Allen belt electrons have been shown to have a clear dependence on solar wind speed and on the duration of southward interplanetary magnetic field. However, individual case study analyses also have demonstrated that many geomagnetic storms produce little in the way of outer belt enhancements and, in fact, may produce substantial losses of relativistic electrons. In this study, focused upon a key period in August-September 2014, we use GOES geostationary orbit electron flux data and Van Allen Probes particle and fields data to study the process of radiation belt electron acceleration. One particular interval, 13-22 September, initiated by a short-lived geomagnetic storm and characterized by a long period of primarily northward IMF, showed strong depletion of. . .
Date: 07/2015 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2015JA021234 Available at: http://doi.wiley.com/10.1002/2015JA021234
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Authors: Baker D.N., Zhao H., Li X, Kanekal S.G., Jaynes A.N., et al.
Title: Comparison of Van Allen Probes Energetic Electron Data with Corresponding GOES‐15 Measurements: 2012‐2018
Abstract: Electron fluxes (especially at energies E > 0.8 and >2 MeV) have been measured for many years by sensors on board the Geostationary Operational Environmental Satellite (GOES). These long‐term data (nominally at L~6.6) have become a mainstay for monitoring the Earth's radiation environment. We have carried out a study directly comparing the comprehensive radiation belt particle measurements from the NASA dual‐spacecraft Van Allen Probes (Radiation Belt Storm Probes) sensor systems with selected GOES operational data. The Van Allen Probes have measured the properties of radiation belt electrons virtually continuously from September 2012 through 2018. We make statistical comparisons of Van Allen Probes electron data near L=6 with concurrent daily averages of equivalent GOES‐15 flux . . .
Date: 11/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027331 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027331
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Authors: Zhao H., Johnston W.R., Baker D.N., Li X, Ni B, et al.
Title: Characterization and Evolution of Radiation Belt Electron Energy Spectra Based on the Van Allen Probes Measurements
Abstract: 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 dominant in the outer radiation belt outside the plasmasphere, power law spectra usually appear at high L‐shells during injections of lower‐energy electrons, and BOT spectra commonly dominate inside the plasmasphere at L>2.5 during relatively quiet times. The. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA026697 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA026697
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ultrarelativistic electrons
Authors: Zhao H., Baker D.N., Li X, Malaspina D.M., Jaynes A.N., et al.
Title: On the Acceleration Mechanism of Ultrarelativistic Electrons in the Center of the Outer Radiation Belt: A Statistical Study
Abstract: Using energetic particle and wave measurements from the Van Allen Probes, Polar Orbiting Environmental Satellites (POES), and Geostationary Operational Environmental Satellite (GOES), the acceleration mechanism of ultrarelativistic electrons (>3 MeV) in the center of the outer radiation belt is investigated statistically. A superposed epoch analysis is conducted using 19 storms, which caused flux enhancements of 1.8–7.7 MeV electrons. The evolution of electron phase space density radial profile suggests an energy‐dependent acceleration of ultrarelativistic electrons in the outer belt. Especially, for electrons with very high energies (~7 MeV), prevalent positive phase space density radial gradients support inward radial diffusion being responsible for electron acceleration in the cente. . .
Date: 10/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027111 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027111
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ULF waves
Authors: Jaynes A.N., Baker D.N., Singer H.J., Rodriguez J.V., Loto'aniu T.M., et al.
Title: Source and Seed Populations for Relativistic Electrons: Their Roles in Radiation Belt Changes
Abstract: Strong enhancements of outer Van Allen belt electrons have been shown to have a clear dependence on solar wind speed and on the duration of southward interplanetary magnetic field. However, individual case study analyses also have demonstrated that many geomagnetic storms produce little in the way of outer belt enhancements and, in fact, may produce substantial losses of relativistic electrons. In this study, focused upon a key period in August-September 2014, we use GOES geostationary orbit electron flux data and Van Allen Probes particle and fields data to study the process of radiation belt electron acceleration. One particular interval, 13-22 September, initiated by a short-lived geomagnetic storm and characterized by a long period of primarily northward IMF, showed strong depletion of. . .
Date: 07/2015 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2015JA021234 Available at: http://doi.wiley.com/10.1002/2015JA021234
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substorms
Authors: Jaynes A.N., Baker D.N., Singer H.J., Rodriguez J.V., Loto'aniu T.M., et al.
Title: Source and Seed Populations for Relativistic Electrons: Their Roles in Radiation Belt Changes
Abstract: Strong enhancements of outer Van Allen belt electrons have been shown to have a clear dependence on solar wind speed and on the duration of southward interplanetary magnetic field. However, individual case study analyses also have demonstrated that many geomagnetic storms produce little in the way of outer belt enhancements and, in fact, may produce substantial losses of relativistic electrons. In this study, focused upon a key period in August-September 2014, we use GOES geostationary orbit electron flux data and Van Allen Probes particle and fields data to study the process of radiation belt electron acceleration. One particular interval, 13-22 September, initiated by a short-lived geomagnetic storm and characterized by a long period of primarily northward IMF, showed strong depletion of. . .
Date: 07/2015 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2015JA021234 Available at: http://doi.wiley.com/10.1002/2015JA021234
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Space weather
Authors: Baker D.N., Zhao H., Li X, Kanekal S.G., Jaynes A.N., et al.
Title: Comparison of Van Allen Probes Energetic Electron Data with Corresponding GOES‐15 Measurements: 2012‐2018
Abstract: Electron fluxes (especially at energies E > 0.8 and >2 MeV) have been measured for many years by sensors on board the Geostationary Operational Environmental Satellite (GOES). These long‐term data (nominally at L~6.6) have become a mainstay for monitoring the Earth's radiation environment. We have carried out a study directly comparing the comprehensive radiation belt particle measurements from the NASA dual‐spacecraft Van Allen Probes (Radiation Belt Storm Probes) sensor systems with selected GOES operational data. The Van Allen Probes have measured the properties of radiation belt electrons virtually continuously from September 2012 through 2018. We make statistical comparisons of Van Allen Probes electron data near L=6 with concurrent daily averages of equivalent GOES‐15 flux . . .
Date: 11/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027331 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027331
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relativistic electrons
Authors: Jaynes A.N., Baker D.N., Singer H.J., Rodriguez J.V., Loto'aniu T.M., et al.
Title: Source and Seed Populations for Relativistic Electrons: Their Roles in Radiation Belt Changes
Abstract: Strong enhancements of outer Van Allen belt electrons have been shown to have a clear dependence on solar wind speed and on the duration of southward interplanetary magnetic field. However, individual case study analyses also have demonstrated that many geomagnetic storms produce little in the way of outer belt enhancements and, in fact, may produce substantial losses of relativistic electrons. In this study, focused upon a key period in August-September 2014, we use GOES geostationary orbit electron flux data and Van Allen Probes particle and fields data to study the process of radiation belt electron acceleration. One particular interval, 13-22 September, initiated by a short-lived geomagnetic storm and characterized by a long period of primarily northward IMF, showed strong depletion of. . .
Date: 07/2015 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2015JA021234 Available at: http://doi.wiley.com/10.1002/2015JA021234
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RBSP satellite
Authors: Xu Jiyao, He Zhaohai, Baker D.N., Roth Ilan, Wang C., et al.
Title: Characteristics of high energy proton responses to geomagnetic activities in the inner radiation belt observed by the RBSP satellite
Abstract: High energy trapped particles in the radiation belts constitute potential threats to the functionality of satellites as they enter into those regions. In the inner radiation belt, the characteristics of high‐energy (>20MeV) protons variations during geomagnetic activity times have been studied by implementing four‐year (2013‐2016) observations of the Van Allen probes. An empirical formula has been used to remove the satellite orbit effect, by which proton fluxes have been normalized to the geomagnetic equator. Case studies show that the region of L<1.7 is relatively stable, while L>1.7 is more dynamic and the most significant variation of proton fluxes occurs at L=2.0. The four‐year survey at L=2.0 indicates that for every geomagnetic storm, sharp descent in proton fluxes is accomp. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2018JA026205 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026205
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Radiation belts
Authors: Zhao H., Baker D.N., Li X, Malaspina D.M., Jaynes A.N., et al.
Title: On the Acceleration Mechanism of Ultrarelativistic Electrons in the Center of the Outer Radiation Belt: A Statistical Study
Abstract: Using energetic particle and wave measurements from the Van Allen Probes, Polar Orbiting Environmental Satellites (POES), and Geostationary Operational Environmental Satellite (GOES), the acceleration mechanism of ultrarelativistic electrons (>3 MeV) in the center of the outer radiation belt is investigated statistically. A superposed epoch analysis is conducted using 19 storms, which caused flux enhancements of 1.8–7.7 MeV electrons. The evolution of electron phase space density radial profile suggests an energy‐dependent acceleration of ultrarelativistic electrons in the outer belt. Especially, for electrons with very high energies (~7 MeV), prevalent positive phase space density radial gradients support inward radial diffusion being responsible for electron acceleration in the cente. . .
Date: 10/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027111 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027111
More Details
Authors: Jaynes A.N., Baker D.N., Singer H.J., Rodriguez J.V., Loto'aniu T.M., et al.
Title: Source and Seed Populations for Relativistic Electrons: Their Roles in Radiation Belt Changes
Abstract: Strong enhancements of outer Van Allen belt electrons have been shown to have a clear dependence on solar wind speed and on the duration of southward interplanetary magnetic field. However, individual case study analyses also have demonstrated that many geomagnetic storms produce little in the way of outer belt enhancements and, in fact, may produce substantial losses of relativistic electrons. In this study, focused upon a key period in August-September 2014, we use GOES geostationary orbit electron flux data and Van Allen Probes particle and fields data to study the process of radiation belt electron acceleration. One particular interval, 13-22 September, initiated by a short-lived geomagnetic storm and characterized by a long period of primarily northward IMF, showed strong depletion of. . .
Date: 07/2015 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2015JA021234 Available at: http://doi.wiley.com/10.1002/2015JA021234
More Details
Authors: Baker D.N., Zhao H., Li X, Kanekal S.G., Jaynes A.N., et al.
Title: Comparison of Van Allen Probes Energetic Electron Data with Corresponding GOES‐15 Measurements: 2012‐2018
Abstract: Electron fluxes (especially at energies E > 0.8 and >2 MeV) have been measured for many years by sensors on board the Geostationary Operational Environmental Satellite (GOES). These long‐term data (nominally at L~6.6) have become a mainstay for monitoring the Earth's radiation environment. We have carried out a study directly comparing the comprehensive radiation belt particle measurements from the NASA dual‐spacecraft Van Allen Probes (Radiation Belt Storm Probes) sensor systems with selected GOES operational data. The Van Allen Probes have measured the properties of radiation belt electrons virtually continuously from September 2012 through 2018. We make statistical comparisons of Van Allen Probes electron data near L=6 with concurrent daily averages of equivalent GOES‐15 flux . . .
Date: 11/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027331 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027331
More Details
radiation belt electrons
Authors: Zhao H., Johnston W.R., Baker D.N., Li X, Ni B, et al.
Title: Characterization and Evolution of Radiation Belt Electron Energy Spectra Based on the Van Allen Probes Measurements
Abstract: 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 dominant in the outer radiation belt outside the plasmasphere, power law spectra usually appear at high L‐shells during injections of lower‐energy electrons, and BOT spectra commonly dominate inside the plasmasphere at L>2.5 during relatively quiet times. The. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA026697 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA026697
More Details
prompt responses
Authors: Xu Jiyao, He Zhaohai, Baker D.N., Roth Ilan, Wang C., et al.
Title: Characteristics of high energy proton responses to geomagnetic activities in the inner radiation belt observed by the RBSP satellite
Abstract: High energy trapped particles in the radiation belts constitute potential threats to the functionality of satellites as they enter into those regions. In the inner radiation belt, the characteristics of high‐energy (>20MeV) protons variations during geomagnetic activity times have been studied by implementing four‐year (2013‐2016) observations of the Van Allen probes. An empirical formula has been used to remove the satellite orbit effect, by which proton fluxes have been normalized to the geomagnetic equator. Case studies show that the region of L<1.7 is relatively stable, while L>1.7 is more dynamic and the most significant variation of proton fluxes occurs at L=2.0. The four‐year survey at L=2.0 indicates that for every geomagnetic storm, sharp descent in proton fluxes is accomp. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2018JA026205 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026205
More Details
Power law energy spectrum
Authors: Zhao H., Johnston W.R., Baker D.N., Li X, Ni B, et al.
Title: Characterization and Evolution of Radiation Belt Electron Energy Spectra Based on the Van Allen Probes Measurements
Abstract: 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 dominant in the outer radiation belt outside the plasmasphere, power law spectra usually appear at high L‐shells during injections of lower‐energy electrons, and BOT spectra commonly dominate inside the plasmasphere at L>2.5 during relatively quiet times. The. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA026697 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA026697
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Plasmapause
Authors: Zhao H., Johnston W.R., Baker D.N., Li X, Ni B, et al.
Title: Characterization and Evolution of Radiation Belt Electron Energy Spectra Based on the Van Allen Probes Measurements
Abstract: 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 dominant in the outer radiation belt outside the plasmasphere, power law spectra usually appear at high L‐shells during injections of lower‐energy electrons, and BOT spectra commonly dominate inside the plasmasphere at L>2.5 during relatively quiet times. The. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA026697 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA026697
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Phase space density
Authors: Zhao H., Baker D.N., Li X, Malaspina D.M., Jaynes A.N., et al.
Title: On the Acceleration Mechanism of Ultrarelativistic Electrons in the Center of the Outer Radiation Belt: A Statistical Study
Abstract: Using energetic particle and wave measurements from the Van Allen Probes, Polar Orbiting Environmental Satellites (POES), and Geostationary Operational Environmental Satellite (GOES), the acceleration mechanism of ultrarelativistic electrons (>3 MeV) in the center of the outer radiation belt is investigated statistically. A superposed epoch analysis is conducted using 19 storms, which caused flux enhancements of 1.8–7.7 MeV electrons. The evolution of electron phase space density radial profile suggests an energy‐dependent acceleration of ultrarelativistic electrons in the outer belt. Especially, for electrons with very high energies (~7 MeV), prevalent positive phase space density radial gradients support inward radial diffusion being responsible for electron acceleration in the cente. . .
Date: 10/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027111 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027111
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one‐to‐one correspondence
Authors: Xu Jiyao, He Zhaohai, Baker D.N., Roth Ilan, Wang C., et al.
Title: Characteristics of high energy proton responses to geomagnetic activities in the inner radiation belt observed by the RBSP satellite
Abstract: High energy trapped particles in the radiation belts constitute potential threats to the functionality of satellites as they enter into those regions. In the inner radiation belt, the characteristics of high‐energy (>20MeV) protons variations during geomagnetic activity times have been studied by implementing four‐year (2013‐2016) observations of the Van Allen probes. An empirical formula has been used to remove the satellite orbit effect, by which proton fluxes have been normalized to the geomagnetic equator. Case studies show that the region of L<1.7 is relatively stable, while L>1.7 is more dynamic and the most significant variation of proton fluxes occurs at L=2.0. The four‐year survey at L=2.0 indicates that for every geomagnetic storm, sharp descent in proton fluxes is accomp. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2018JA026205 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026205
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Magnetospheric configuration
Authors: Baker D.N., Zhao H., Li X, Kanekal S.G., Jaynes A.N., et al.
Title: Comparison of Van Allen Probes Energetic Electron Data with Corresponding GOES‐15 Measurements: 2012‐2018
Abstract: Electron fluxes (especially at energies E > 0.8 and >2 MeV) have been measured for many years by sensors on board the Geostationary Operational Environmental Satellite (GOES). These long‐term data (nominally at L~6.6) have become a mainstay for monitoring the Earth's radiation environment. We have carried out a study directly comparing the comprehensive radiation belt particle measurements from the NASA dual‐spacecraft Van Allen Probes (Radiation Belt Storm Probes) sensor systems with selected GOES operational data. The Van Allen Probes have measured the properties of radiation belt electrons virtually continuously from September 2012 through 2018. We make statistical comparisons of Van Allen Probes electron data near L=6 with concurrent daily averages of equivalent GOES‐15 flux . . .
Date: 11/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027331 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027331
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Magnetosphere:Inner
Authors: Baker D.N., Zhao H., Li X, Kanekal S.G., Jaynes A.N., et al.
Title: Comparison of Van Allen Probes Energetic Electron Data with Corresponding GOES‐15 Measurements: 2012‐2018
Abstract: Electron fluxes (especially at energies E > 0.8 and >2 MeV) have been measured for many years by sensors on board the Geostationary Operational Environmental Satellite (GOES). These long‐term data (nominally at L~6.6) have become a mainstay for monitoring the Earth's radiation environment. We have carried out a study directly comparing the comprehensive radiation belt particle measurements from the NASA dual‐spacecraft Van Allen Probes (Radiation Belt Storm Probes) sensor systems with selected GOES operational data. The Van Allen Probes have measured the properties of radiation belt electrons virtually continuously from September 2012 through 2018. We make statistical comparisons of Van Allen Probes electron data near L=6 with concurrent daily averages of equivalent GOES‐15 flux . . .
Date: 11/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027331 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027331
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Local Acceleration
Authors: Zhao H., Baker D.N., Li X, Malaspina D.M., Jaynes A.N., et al.
Title: On the Acceleration Mechanism of Ultrarelativistic Electrons in the Center of the Outer Radiation Belt: A Statistical Study
Abstract: Using energetic particle and wave measurements from the Van Allen Probes, Polar Orbiting Environmental Satellites (POES), and Geostationary Operational Environmental Satellite (GOES), the acceleration mechanism of ultrarelativistic electrons (>3 MeV) in the center of the outer radiation belt is investigated statistically. A superposed epoch analysis is conducted using 19 storms, which caused flux enhancements of 1.8–7.7 MeV electrons. The evolution of electron phase space density radial profile suggests an energy‐dependent acceleration of ultrarelativistic electrons in the outer belt. Especially, for electrons with very high energies (~7 MeV), prevalent positive phase space density radial gradients support inward radial diffusion being responsible for electron acceleration in the cente. . .
Date: 10/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027111 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027111
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Inward radial diffusion
Authors: Zhao H., Baker D.N., Li X, Malaspina D.M., Jaynes A.N., et al.
Title: On the Acceleration Mechanism of Ultrarelativistic Electrons in the Center of the Outer Radiation Belt: A Statistical Study
Abstract: Using energetic particle and wave measurements from the Van Allen Probes, Polar Orbiting Environmental Satellites (POES), and Geostationary Operational Environmental Satellite (GOES), the acceleration mechanism of ultrarelativistic electrons (>3 MeV) in the center of the outer radiation belt is investigated statistically. A superposed epoch analysis is conducted using 19 storms, which caused flux enhancements of 1.8–7.7 MeV electrons. The evolution of electron phase space density radial profile suggests an energy‐dependent acceleration of ultrarelativistic electrons in the outer belt. Especially, for electrons with very high energies (~7 MeV), prevalent positive phase space density radial gradients support inward radial diffusion being responsible for electron acceleration in the cente. . .
Date: 10/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027111 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027111
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Inner radiation belt
Authors: Xu Jiyao, He Zhaohai, Baker D.N., Roth Ilan, Wang C., et al.
Title: Characteristics of high energy proton responses to geomagnetic activities in the inner radiation belt observed by the RBSP satellite
Abstract: High energy trapped particles in the radiation belts constitute potential threats to the functionality of satellites as they enter into those regions. In the inner radiation belt, the characteristics of high‐energy (>20MeV) protons variations during geomagnetic activity times have been studied by implementing four‐year (2013‐2016) observations of the Van Allen probes. An empirical formula has been used to remove the satellite orbit effect, by which proton fluxes have been normalized to the geomagnetic equator. Case studies show that the region of L<1.7 is relatively stable, while L>1.7 is more dynamic and the most significant variation of proton fluxes occurs at L=2.0. The four‐year survey at L=2.0 indicates that for every geomagnetic storm, sharp descent in proton fluxes is accomp. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2018JA026205 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026205
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high energy proton
Authors: Xu Jiyao, He Zhaohai, Baker D.N., Roth Ilan, Wang C., et al.
Title: Characteristics of high energy proton responses to geomagnetic activities in the inner radiation belt observed by the RBSP satellite
Abstract: High energy trapped particles in the radiation belts constitute potential threats to the functionality of satellites as they enter into those regions. In the inner radiation belt, the characteristics of high‐energy (>20MeV) protons variations during geomagnetic activity times have been studied by implementing four‐year (2013‐2016) observations of the Van Allen probes. An empirical formula has been used to remove the satellite orbit effect, by which proton fluxes have been normalized to the geomagnetic equator. Case studies show that the region of L<1.7 is relatively stable, while L>1.7 is more dynamic and the most significant variation of proton fluxes occurs at L=2.0. The four‐year survey at L=2.0 indicates that for every geomagnetic storm, sharp descent in proton fluxes is accomp. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2018JA026205 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026205
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geomagnetic activities
Authors: Xu Jiyao, He Zhaohai, Baker D.N., Roth Ilan, Wang C., et al.
Title: Characteristics of high energy proton responses to geomagnetic activities in the inner radiation belt observed by the RBSP satellite
Abstract: High energy trapped particles in the radiation belts constitute potential threats to the functionality of satellites as they enter into those regions. In the inner radiation belt, the characteristics of high‐energy (>20MeV) protons variations during geomagnetic activity times have been studied by implementing four‐year (2013‐2016) observations of the Van Allen probes. An empirical formula has been used to remove the satellite orbit effect, by which proton fluxes have been normalized to the geomagnetic equator. Case studies show that the region of L<1.7 is relatively stable, while L>1.7 is more dynamic and the most significant variation of proton fluxes occurs at L=2.0. The four‐year survey at L=2.0 indicates that for every geomagnetic storm, sharp descent in proton fluxes is accomp. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2018JA026205 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026205
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Exponential energy spectrum
Authors: Zhao H., Johnston W.R., Baker D.N., Li X, Ni B, et al.
Title: Characterization and Evolution of Radiation Belt Electron Energy Spectra Based on the Van Allen Probes Measurements
Abstract: 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 dominant in the outer radiation belt outside the plasmasphere, power law spectra usually appear at high L‐shells during injections of lower‐energy electrons, and BOT spectra commonly dominate inside the plasmasphere at L>2.5 during relatively quiet times. The. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA026697 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA026697
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Energy spectrum
Authors: Zhao H., Johnston W.R., Baker D.N., Li X, Ni B, et al.
Title: Characterization and Evolution of Radiation Belt Electron Energy Spectra Based on the Van Allen Probes Measurements
Abstract: 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 dominant in the outer radiation belt outside the plasmasphere, power law spectra usually appear at high L‐shells during injections of lower‐energy electrons, and BOT spectra commonly dominate inside the plasmasphere at L>2.5 during relatively quiet times. The. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA026697 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA026697
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energetic particles
Authors: Baker D.N., Zhao H., Li X, Kanekal S.G., Jaynes A.N., et al.
Title: Comparison of Van Allen Probes Energetic Electron Data with Corresponding GOES‐15 Measurements: 2012‐2018
Abstract: Electron fluxes (especially at energies E > 0.8 and >2 MeV) have been measured for many years by sensors on board the Geostationary Operational Environmental Satellite (GOES). These long‐term data (nominally at L~6.6) have become a mainstay for monitoring the Earth's radiation environment. We have carried out a study directly comparing the comprehensive radiation belt particle measurements from the NASA dual‐spacecraft Van Allen Probes (Radiation Belt Storm Probes) sensor systems with selected GOES operational data. The Van Allen Probes have measured the properties of radiation belt electrons virtually continuously from September 2012 through 2018. We make statistical comparisons of Van Allen Probes electron data near L=6 with concurrent daily averages of equivalent GOES‐15 flux . . .
Date: 11/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027331 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027331
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Bump‐on‐tail energy spectrum
Authors: Zhao H., Johnston W.R., Baker D.N., Li X, Ni B, et al.
Title: Characterization and Evolution of Radiation Belt Electron Energy Spectra Based on the Van Allen Probes Measurements
Abstract: 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 dominant in the outer radiation belt outside the plasmasphere, power law spectra usually appear at high L‐shells during injections of lower‐energy electrons, and BOT spectra commonly dominate inside the plasmasphere at L>2.5 during relatively quiet times. The. . .
Date: 05/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA026697 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA026697
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Acceleration mechanism
Authors: Zhao H., Baker D.N., Li X, Malaspina D.M., Jaynes A.N., et al.
Title: On the Acceleration Mechanism of Ultrarelativistic Electrons in the Center of the Outer Radiation Belt: A Statistical Study
Abstract: Using energetic particle and wave measurements from the Van Allen Probes, Polar Orbiting Environmental Satellites (POES), and Geostationary Operational Environmental Satellite (GOES), the acceleration mechanism of ultrarelativistic electrons (>3 MeV) in the center of the outer radiation belt is investigated statistically. A superposed epoch analysis is conducted using 19 storms, which caused flux enhancements of 1.8–7.7 MeV electrons. The evolution of electron phase space density radial profile suggests an energy‐dependent acceleration of ultrarelativistic electrons in the outer belt. Especially, for electrons with very high energies (~7 MeV), prevalent positive phase space density radial gradients support inward radial diffusion being responsible for electron acceleration in the cente. . .
Date: 10/2019 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2019JA027111 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JA027111
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