Bibliography

Correlated Pc4-5 ULF waves, whistler-mode chorus and pulsating aurora observed by the Van Allen Probes and ground-based systems

Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch-angle scattering of 10\textquoterights keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and 10\textquoterights keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4-5 compressional pulsations and modulation of whistler-mode chorus using THEMIS. In the current study, we present simultaneous in-situ observations of structured chorus waves and an apparent field line resonance (in the Pc4-5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4-5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth\textquoterights atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with the same modulation in a nearby pulsating aurora patch. Such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades, and may be a result of nonlinear chorus wave interactions in the equatorial region.

Jaynes, A.; Lessard, M.; Takahashi, K.; Ali, A.; Malaspina, D.; Michell, R.; Spanswick, E.; Baker, D.; Blake, J.; Cully, C.; Donovan, E.; Kletzing, C.; Reeves, G.; Samara, M.; Spence, H.; Wygant, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021380

aurora; precipitation; pulsating aurora; substorms; ULF waves; Van Allen Probes; VLF waves

Correlated Pc4-5 ULF waves, whistler-mode chorus and pulsating aurora observed by the Van Allen Probes and ground-based systems

Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch-angle scattering of 10\textquoterights keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and 10\textquoterights keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4-5 compressional pulsations and modulation of whistler-mode chorus using THEMIS. In the current study, we present simultaneous in-situ observations of structured chorus waves and an apparent field line resonance (in the Pc4-5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4-5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth\textquoterights atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with the same modulation in a nearby pulsating aurora patch. Such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades, and may be a result of nonlinear chorus wave interactions in the equatorial region.

Jaynes, A.; Lessard, M.; Takahashi, K.; Ali, A.; Malaspina, D.; Michell, R.; Spanswick, E.; Baker, D.; Blake, J.; Cully, C.; Donovan, E.; Kletzing, C.; Reeves, G.; Samara, M.; Spence, H.; Wygant, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021380

aurora; precipitation; pulsating aurora; substorms; ULF waves; Van Allen Probes; VLF waves

Correlated Pc4-5 ULF waves, whistler-mode chorus and pulsating aurora observed by the Van Allen Probes and ground-based systems

Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch-angle scattering of 10\textquoterights keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and 10\textquoterights keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4-5 compressional pulsations and modulation of whistler-mode chorus using THEMIS. In the current study, we present simultaneous in-situ observations of structured chorus waves and an apparent field line resonance (in the Pc4-5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4-5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth\textquoterights atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with the same modulation in a nearby pulsating aurora patch. Such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades, and may be a result of nonlinear chorus wave interactions in the equatorial region.

Jaynes, A.; Lessard, M.; Takahashi, K.; Ali, A.; Malaspina, D.; Michell, R.; Spanswick, E.; Baker, D.; Blake, J.; Cully, C.; Donovan, E.; Kletzing, C.; Reeves, G.; Samara, M.; Spence, H.; Wygant, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021380

aurora; precipitation; pulsating aurora; substorms; ULF waves; Van Allen Probes; VLF waves

Correlated Pc4-5 ULF waves, whistler-mode chorus and pulsating aurora observed by the Van Allen Probes and ground-based systems

Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch-angle scattering of 10\textquoterights keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and 10\textquoterights keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4-5 compressional pulsations and modulation of whistler-mode chorus using THEMIS. In the current study, we present simultaneous in-situ observations of structured chorus waves and an apparent field line resonance (in the Pc4-5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4-5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth\textquoterights atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with the same modulation in a nearby pulsating aurora patch. Such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades, and may be a result of nonlinear chorus wave interactions in the equatorial region.

Jaynes, A.; Lessard, M.; Takahashi, K.; Ali, A.; Malaspina, D.; Michell, R.; Spanswick, E.; Baker, D.; Blake, J.; Cully, C.; Donovan, E.; Kletzing, C.; Reeves, G.; Samara, M.; Spence, H.; Wygant, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021380

aurora; precipitation; pulsating aurora; substorms; ULF waves; Van Allen Probes; VLF waves

Correlated Pc4-5 ULF waves, whistler-mode chorus and pulsating aurora observed by the Van Allen Probes and ground-based systems

Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch-angle scattering of 10\textquoterights keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and 10\textquoterights keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4-5 compressional pulsations and modulation of whistler-mode chorus using THEMIS. In the current study, we present simultaneous in-situ observations of structured chorus waves and an apparent field line resonance (in the Pc4-5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4-5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth\textquoterights atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with the same modulation in a nearby pulsating aurora patch. Such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades, and may be a result of nonlinear chorus wave interactions in the equatorial region.

Jaynes, A.; Lessard, M.; Takahashi, K.; Ali, A.; Malaspina, D.; Michell, R.; Spanswick, E.; Baker, D.; Blake, J.; Cully, C.; Donovan, E.; Kletzing, C.; Reeves, G.; Samara, M.; Spence, H.; Wygant, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021380

aurora; precipitation; pulsating aurora; substorms; ULF waves; Van Allen Probes; VLF waves

Correlated Pc4-5 ULF waves, whistler-mode chorus and pulsating aurora observed by the Van Allen Probes and ground-based systems

Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch-angle scattering of 10\textquoterights keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and 10\textquoterights keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4-5 compressional pulsations and modulation of whistler-mode chorus using THEMIS. In the current study, we present simultaneous in-situ observations of structured chorus waves and an apparent field line resonance (in the Pc4-5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4-5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth\textquoterights atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with the same modulation in a nearby pulsating aurora patch. Such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades, and may be a result of nonlinear chorus wave interactions in the equatorial region.

Jaynes, A.; Lessard, M.; Takahashi, K.; Ali, A.; Malaspina, D.; Michell, R.; Spanswick, E.; Baker, D.; Blake, J.; Cully, C.; Donovan, E.; Kletzing, C.; Reeves, G.; Samara, M.; Spence, H.; Wygant, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021380

aurora; precipitation; pulsating aurora; substorms; ULF waves; Van Allen Probes; VLF waves

Dense plasma and Kelvin-Helmholtz waves at Earth\textquoterights dayside magnetopause

Spacecraft observations of boundary waves at the dayside terrestrial magnetopause and their ground-based signatures are presented. Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft measured boundary waves at the magnetopause while ground-based HF radar measured corresponding signatures in the ionosphere indicating a large-scale response and tailward propagating waves. The properties of the oscillations are consistent with linear phase Kelvin-Helmholtz waves along the magnetopause boundary. During this time period multiple THEMIS spacecraft also measured a plasmaspheric plume contacting the local magnetopause and mass loading the boundary. Previous work has demonstrated that increasing the density at the magnetopause can lower the efficiency of reconnection. Extending this further, present observations suggest that a plume can modulate instability processes such as the Kelvin-Helmholtz instability and allow them to form closer to the subsolar point along the magnetopause than without a plume. The current THEMIS observations from 21 September 2010 are consistent with a theory which predicts that increasing the density at the boundary will lower the Kelvin-Helmholtz threshold and allow waves to form for a lower velocity shear.

Walsh, B.; Thomas, E.; Hwang, K.-J.; Baker, J.; Ruohoniemi, J.; Bonnell, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021014

Kelvin-Helmholtz; magnetopause

Dense plasma and Kelvin-Helmholtz waves at Earth\textquoterights dayside magnetopause

Spacecraft observations of boundary waves at the dayside terrestrial magnetopause and their ground-based signatures are presented. Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft measured boundary waves at the magnetopause while ground-based HF radar measured corresponding signatures in the ionosphere indicating a large-scale response and tailward propagating waves. The properties of the oscillations are consistent with linear phase Kelvin-Helmholtz waves along the magnetopause boundary. During this time period multiple THEMIS spacecraft also measured a plasmaspheric plume contacting the local magnetopause and mass loading the boundary. Previous work has demonstrated that increasing the density at the magnetopause can lower the efficiency of reconnection. Extending this further, present observations suggest that a plume can modulate instability processes such as the Kelvin-Helmholtz instability and allow them to form closer to the subsolar point along the magnetopause than without a plume. The current THEMIS observations from 21 September 2010 are consistent with a theory which predicts that increasing the density at the boundary will lower the Kelvin-Helmholtz threshold and allow waves to form for a lower velocity shear.

Walsh, B.; Thomas, E.; Hwang, K.-J.; Baker, J.; Ruohoniemi, J.; Bonnell, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021014

Kelvin-Helmholtz; magnetopause

Dense plasma and Kelvin-Helmholtz waves at Earth\textquoterights dayside magnetopause

Spacecraft observations of boundary waves at the dayside terrestrial magnetopause and their ground-based signatures are presented. Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft measured boundary waves at the magnetopause while ground-based HF radar measured corresponding signatures in the ionosphere indicating a large-scale response and tailward propagating waves. The properties of the oscillations are consistent with linear phase Kelvin-Helmholtz waves along the magnetopause boundary. During this time period multiple THEMIS spacecraft also measured a plasmaspheric plume contacting the local magnetopause and mass loading the boundary. Previous work has demonstrated that increasing the density at the magnetopause can lower the efficiency of reconnection. Extending this further, present observations suggest that a plume can modulate instability processes such as the Kelvin-Helmholtz instability and allow them to form closer to the subsolar point along the magnetopause than without a plume. The current THEMIS observations from 21 September 2010 are consistent with a theory which predicts that increasing the density at the boundary will lower the Kelvin-Helmholtz threshold and allow waves to form for a lower velocity shear.

Walsh, B.; Thomas, E.; Hwang, K.-J.; Baker, J.; Ruohoniemi, J.; Bonnell, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015JA021014

Kelvin-Helmholtz; magnetopause

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 around L~3.7, and their peak flux location moves to lower L-shells during storm recovery phases. Relativistic electrons (>=~1 MeV) are nearly equally likely to produce enhancement, depletion, and no-change events in the outer belt. We also show that the L-shell of peak flux correlates to storm magnitude only for 100s of keV electrons.

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

Published by: Geophysical Research Letters      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015GL064747

electrons; Van Allen Probes; Geomagnetic storms; Radiation belts

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 around L~3.7, and their peak flux location moves to lower L-shells during storm recovery phases. Relativistic electrons (>=~1 MeV) are nearly equally likely to produce enhancement, depletion, and no-change events in the outer belt. We also show that the L-shell of peak flux correlates to storm magnitude only for 100s of keV electrons.

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

Published by: Geophysical Research Letters      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015GL064747

electrons; Van Allen Probes; Geomagnetic storms; Radiation belts

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 around L~3.7, and their peak flux location moves to lower L-shells during storm recovery phases. Relativistic electrons (>=~1 MeV) are nearly equally likely to produce enhancement, depletion, and no-change events in the outer belt. We also show that the L-shell of peak flux correlates to storm magnitude only for 100s of keV electrons.

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

Published by: Geophysical Research Letters      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015GL064747

electrons; Van Allen Probes; Geomagnetic storms; Radiation belts

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 around L~3.7, and their peak flux location moves to lower L-shells during storm recovery phases. Relativistic electrons (>=~1 MeV) are nearly equally likely to produce enhancement, depletion, and no-change events in the outer belt. We also show that the L-shell of peak flux correlates to storm magnitude only for 100s of keV electrons.

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

Published by: Geophysical Research Letters      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015GL064747

electrons; Van Allen Probes; Geomagnetic storms; Radiation belts

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 around L~3.7, and their peak flux location moves to lower L-shells during storm recovery phases. Relativistic electrons (>=~1 MeV) are nearly equally likely to produce enhancement, depletion, and no-change events in the outer belt. We also show that the L-shell of peak flux correlates to storm magnitude only for 100s of keV electrons.

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

Published by: Geophysical Research Letters      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015GL064747

electrons; Van Allen Probes; Geomagnetic storms; Radiation belts

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 around L~3.7, and their peak flux location moves to lower L-shells during storm recovery phases. Relativistic electrons (>=~1 MeV) are nearly equally likely to produce enhancement, depletion, and no-change events in the outer belt. We also show that the L-shell of peak flux correlates to storm magnitude only for 100s of keV electrons.

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

Published by: Geophysical Research Letters      Published on: 07/2015

YEAR: 2015     DOI: 10.1002/2015GL064747

electrons; Van Allen Probes; Geomagnetic storms; Radiation belts

Extreme geomagnetic disturbances due to shocks within CMEs

We report on features of solar wind-magnetosphere coupling elicited by shocks propagating through coronal mass ejections (CMEs) by analyzing the intense geomagnetic storm of 6 August 1998. During this event, the dynamic pressure enhancement at the shock combined with a simultaneous increase in the southward component of the magnetic field resulted in a large earthward retreat of Earth\textquoterights magnetopause, which remained close to geosynchronous orbit for more than 4 h. This occurred despite the fact that both shock and CME were weak and relatively slow. Another similar example of a weak shock inside a slow CME resulting in an intense geomagnetic storm is the 30 September 2012 event, which strongly depleted the outer radiation belt. We discuss the potential of shocks inside CMEs to cause large geomagnetic effects at Earth, including magnetopause shadowing.

Lugaz, N.; Farrugia, C.; Huang, C.-L.; Spence, H.;

Published by: Geophysical Research Letters      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015GL064530

coronal mass ejections; Geomagnetic storm; magnetopause; magnetosheath; shocks

Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss

Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii1, 2, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss3, 4, 5. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its \textquoteleftquiet\textquoteright pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electron losses and the hiss phenomenon that causes the losses. Losses were observed in the form of bremsstrahlung X-rays generated by hiss-scattered electrons colliding with the Earth\textquoterights atmosphere after removal from the radiation belts. Our results show that changes of up to an order of magnitude in the dynamics of electron loss arising from hiss occur on timescales as short as one to twenty minutes, in association with modulations in plasma density and magnetic field. Furthermore, these loss dynamics are coherent with hiss dynamics on spatial scales comparable to the size of the plasmasphere. This nearly global-scale coherence was not predicted and may affect the short-term evolution of the radiation belts during active times.

Breneman, A.; Halford, A.; Millan, R.; McCarthy, M.; Fennell, J.; Sample, J.; Woodger, L.; Hospodarsky, G.; Wygant, J.; Cattell, C.; Goldstein, J.; Malaspina, D.; Kletzing, C.;

Published by: Nature      Published on: 06/2015

YEAR: 2015     DOI: 10.1038/nature14515

Magnetospheric physics; Van Allen Probes

Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss

Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii1, 2, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss3, 4, 5. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its \textquoteleftquiet\textquoteright pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electron losses and the hiss phenomenon that causes the losses. Losses were observed in the form of bremsstrahlung X-rays generated by hiss-scattered electrons colliding with the Earth\textquoterights atmosphere after removal from the radiation belts. Our results show that changes of up to an order of magnitude in the dynamics of electron loss arising from hiss occur on timescales as short as one to twenty minutes, in association with modulations in plasma density and magnetic field. Furthermore, these loss dynamics are coherent with hiss dynamics on spatial scales comparable to the size of the plasmasphere. This nearly global-scale coherence was not predicted and may affect the short-term evolution of the radiation belts during active times.

Breneman, A.; Halford, A.; Millan, R.; McCarthy, M.; Fennell, J.; Sample, J.; Woodger, L.; Hospodarsky, G.; Wygant, J.; Cattell, C.; Goldstein, J.; Malaspina, D.; Kletzing, C.;

Published by: Nature      Published on: 06/2015

YEAR: 2015     DOI: 10.1038/nature14515

Magnetospheric physics; Van Allen Probes

Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss

Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii1, 2, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss3, 4, 5. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its \textquoteleftquiet\textquoteright pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electron losses and the hiss phenomenon that causes the losses. Losses were observed in the form of bremsstrahlung X-rays generated by hiss-scattered electrons colliding with the Earth\textquoterights atmosphere after removal from the radiation belts. Our results show that changes of up to an order of magnitude in the dynamics of electron loss arising from hiss occur on timescales as short as one to twenty minutes, in association with modulations in plasma density and magnetic field. Furthermore, these loss dynamics are coherent with hiss dynamics on spatial scales comparable to the size of the plasmasphere. This nearly global-scale coherence was not predicted and may affect the short-term evolution of the radiation belts during active times.

Breneman, A.; Halford, A.; Millan, R.; McCarthy, M.; Fennell, J.; Sample, J.; Woodger, L.; Hospodarsky, G.; Wygant, J.; Cattell, C.; Goldstein, J.; Malaspina, D.; Kletzing, C.;

Published by: Nature      Published on: 06/2015

YEAR: 2015     DOI: 10.1038/nature14515

Magnetospheric physics; Van Allen Probes

Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss

Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii1, 2, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss3, 4, 5. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its \textquoteleftquiet\textquoteright pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electron losses and the hiss phenomenon that causes the losses. Losses were observed in the form of bremsstrahlung X-rays generated by hiss-scattered electrons colliding with the Earth\textquoterights atmosphere after removal from the radiation belts. Our results show that changes of up to an order of magnitude in the dynamics of electron loss arising from hiss occur on timescales as short as one to twenty minutes, in association with modulations in plasma density and magnetic field. Furthermore, these loss dynamics are coherent with hiss dynamics on spatial scales comparable to the size of the plasmasphere. This nearly global-scale coherence was not predicted and may affect the short-term evolution of the radiation belts during active times.

Breneman, A.; Halford, A.; Millan, R.; McCarthy, M.; Fennell, J.; Sample, J.; Woodger, L.; Hospodarsky, G.; Wygant, J.; Cattell, C.; Goldstein, J.; Malaspina, D.; Kletzing, C.;

Published by: Nature      Published on: 06/2015

YEAR: 2015     DOI: 10.1038/nature14515

Magnetospheric physics; Van Allen Probes

Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss

Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii1, 2, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss3, 4, 5. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its \textquoteleftquiet\textquoteright pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electron losses and the hiss phenomenon that causes the losses. Losses were observed in the form of bremsstrahlung X-rays generated by hiss-scattered electrons colliding with the Earth\textquoterights atmosphere after removal from the radiation belts. Our results show that changes of up to an order of magnitude in the dynamics of electron loss arising from hiss occur on timescales as short as one to twenty minutes, in association with modulations in plasma density and magnetic field. Furthermore, these loss dynamics are coherent with hiss dynamics on spatial scales comparable to the size of the plasmasphere. This nearly global-scale coherence was not predicted and may affect the short-term evolution of the radiation belts during active times.

Breneman, A.; Halford, A.; Millan, R.; McCarthy, M.; Fennell, J.; Sample, J.; Woodger, L.; Hospodarsky, G.; Wygant, J.; Cattell, C.; Goldstein, J.; Malaspina, D.; Kletzing, C.;

Published by: Nature      Published on: 06/2015

YEAR: 2015     DOI: 10.1038/nature14515

Magnetospheric physics; Van Allen Probes

Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss

Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii1, 2, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss3, 4, 5. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its \textquoteleftquiet\textquoteright pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electron losses and the hiss phenomenon that causes the losses. Losses were observed in the form of bremsstrahlung X-rays generated by hiss-scattered electrons colliding with the Earth\textquoterights atmosphere after removal from the radiation belts. Our results show that changes of up to an order of magnitude in the dynamics of electron loss arising from hiss occur on timescales as short as one to twenty minutes, in association with modulations in plasma density and magnetic field. Furthermore, these loss dynamics are coherent with hiss dynamics on spatial scales comparable to the size of the plasmasphere. This nearly global-scale coherence was not predicted and may affect the short-term evolution of the radiation belts during active times.

Breneman, A.; Halford, A.; Millan, R.; McCarthy, M.; Fennell, J.; Sample, J.; Woodger, L.; Hospodarsky, G.; Wygant, J.; Cattell, C.; Goldstein, J.; Malaspina, D.; Kletzing, C.;

Published by: Nature      Published on: 06/2015

YEAR: 2015     DOI: 10.1038/nature14515

Magnetospheric physics; Van Allen Probes

Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss

Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii1, 2, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss3, 4, 5. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its \textquoteleftquiet\textquoteright pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electron losses and the hiss phenomenon that causes the losses. Losses were observed in the form of bremsstrahlung X-rays generated by hiss-scattered electrons colliding with the Earth\textquoterights atmosphere after removal from the radiation belts. Our results show that changes of up to an order of magnitude in the dynamics of electron loss arising from hiss occur on timescales as short as one to twenty minutes, in association with modulations in plasma density and magnetic field. Furthermore, these loss dynamics are coherent with hiss dynamics on spatial scales comparable to the size of the plasmasphere. This nearly global-scale coherence was not predicted and may affect the short-term evolution of the radiation belts during active times.

Breneman, A.; Halford, A.; Millan, R.; McCarthy, M.; Fennell, J.; Sample, J.; Woodger, L.; Hospodarsky, G.; Wygant, J.; Cattell, C.; Goldstein, J.; Malaspina, D.; Kletzing, C.;

Published by: Nature      Published on: 06/2015

YEAR: 2015     DOI: 10.1038/nature14515

Magnetospheric physics; Van Allen Probes

Nonlinear Bounce Resonances between Magnetosonic Waves and Equatorially Mirroring Electrons

Equatorially mirroring energetic electrons pose an interesting scientific problem, since they generally cannot resonate with any known plasma waves and hence cannot be scattered down to lower pitch angles. Observationally it is well known that the fluxof these equatorial particles does not simply continue to build up indefinitely, and so a mechanism must necessarily exist that transports these particles from a equatorial pitch angle of 90 degrees down to lower values. However this mechanism has not been uniquely identified yet. Here, we investigate the mechanism of bounce resonance with equatorial noise (or fast magnetosonic waves). A test particle simulation is used to examine the effects of monochromatic magnetosonic waves on the equatorially mirroring energetic electrons, with a special interest in characterizing the effectiveness of bounce resonances. Our analysis shows that bounce resonances can occur at the first three harmonics of the bounce frequency (nωb, n = 1 , 2, and 3 ) and can effectively reduce the equatorial pitch angle to values where resonant scattering by whistler-mode waves becomes possible. We demonstrate that the nature of bounce resonance is nonlinear and we propose a nonlinear oscillation model for characterizing bounce resonances using two key parameters, effective wave amplitude \~A and normalized wave number inline image. The threshold for higher harmonic resonance is more strict, favoring higher \~A and inline image and the change in equatorial pitch angle is strongly controlled by inline image. We also investigate the dependence of bounce resonance effects on various physical parameters, including wave amplitude, frequency, wave normal angle and initial phase, plasmadensity, and electron energy. It is found that the effect of bounce resonance is sensitive to the wave normal angle. We suggest that the bounce resonant interaction might lead to an observed pitch angle distribution with a minimum at 90o.

Chen, Lunjin; Maldonado, Armando; Bortnik, Jacob; Thorne, Richard; Li, Jinxing; Dai, Lei; Zhan, Xiaoya;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021174

bounce resonance; equatorioal noise; magnetosonic waves; nonlinear; Radiation belt; wave particle interaction

Nonlinear Bounce Resonances between Magnetosonic Waves and Equatorially Mirroring Electrons

Equatorially mirroring energetic electrons pose an interesting scientific problem, since they generally cannot resonate with any known plasma waves and hence cannot be scattered down to lower pitch angles. Observationally it is well known that the fluxof these equatorial particles does not simply continue to build up indefinitely, and so a mechanism must necessarily exist that transports these particles from a equatorial pitch angle of 90 degrees down to lower values. However this mechanism has not been uniquely identified yet. Here, we investigate the mechanism of bounce resonance with equatorial noise (or fast magnetosonic waves). A test particle simulation is used to examine the effects of monochromatic magnetosonic waves on the equatorially mirroring energetic electrons, with a special interest in characterizing the effectiveness of bounce resonances. Our analysis shows that bounce resonances can occur at the first three harmonics of the bounce frequency (nωb, n = 1 , 2, and 3 ) and can effectively reduce the equatorial pitch angle to values where resonant scattering by whistler-mode waves becomes possible. We demonstrate that the nature of bounce resonance is nonlinear and we propose a nonlinear oscillation model for characterizing bounce resonances using two key parameters, effective wave amplitude \~A and normalized wave number inline image. The threshold for higher harmonic resonance is more strict, favoring higher \~A and inline image and the change in equatorial pitch angle is strongly controlled by inline image. We also investigate the dependence of bounce resonance effects on various physical parameters, including wave amplitude, frequency, wave normal angle and initial phase, plasmadensity, and electron energy. It is found that the effect of bounce resonance is sensitive to the wave normal angle. We suggest that the bounce resonant interaction might lead to an observed pitch angle distribution with a minimum at 90o.

Chen, Lunjin; Maldonado, Armando; Bortnik, Jacob; Thorne, Richard; Li, Jinxing; Dai, Lei; Zhan, Xiaoya;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021174

bounce resonance; equatorioal noise; magnetosonic waves; nonlinear; Radiation belt; wave particle interaction

Relativistic electron scattering by magnetosonic waves: Effects of discrete wave emission and high wave amplitudes

In this paper, we study relativistic electron scattering by fast magnetosonic waves. We compare results of test particle simulations and the quasi-linear theory for different spectra of waves to investigate how a fine structure of the wave emission can influence electron resonant scattering. We show that for a realistically wide distribution of wave normal angles theta (i.e., when the dispersion delta theta >= 0.5 degrees), relativistic electron scattering is similar for a wide wave spectrum and for a spectrum consisting in well-separated ion cyclotron harmonics. Comparisons of test particle simulations with quasi-linear theory show that for delta theta > 0.5 degrees, the quasi-linear approximation describes resonant scattering correctly for a large enough plasma frequency. For a very narrow h distribution (when delta theta >= 0.05 degrees), however, the effect of a fine structure in the wave spectrum becomes important. In this case, quasi-linear theory clearly fails in describing accurately electron scattering by fast magnetosonic waves. We also study the effect of high wave amplitudes on relativistic electron scattering. For typical conditions in the earth\textquoterights radiation belts, the quasi-linear approximation cannot accurately describe electron scattering for waves with averaged amplitudes > 300 pT. We discuss various applications of the obtained results for modeling electron dynamics in the radiation belts and in the Earth\textquoterights magnetotail. (C) 2015 AIP Publishing LLC.

Artemyev, A.; Mourenas, D.; Agapitov, O.; Krasnoselskikh, V.;

Published by: Physics of Plasmas      Published on: 06/2015

YEAR: 2015     DOI: 10.1063/1.4922061

chorus waves; CLUSTER SPACECRAFT; equatorial noise; MAGNETIC-FIELD; PLASMA; Quasi-linear diffusion; radiation belt electrons; RESONANT SCATTERING; Van Allen Probes; WHISTLER-MODE WAVES

Relativistic electron scattering by magnetosonic waves: Effects of discrete wave emission and high wave amplitudes

In this paper, we study relativistic electron scattering by fast magnetosonic waves. We compare results of test particle simulations and the quasi-linear theory for different spectra of waves to investigate how a fine structure of the wave emission can influence electron resonant scattering. We show that for a realistically wide distribution of wave normal angles theta (i.e., when the dispersion delta theta >= 0.5 degrees), relativistic electron scattering is similar for a wide wave spectrum and for a spectrum consisting in well-separated ion cyclotron harmonics. Comparisons of test particle simulations with quasi-linear theory show that for delta theta > 0.5 degrees, the quasi-linear approximation describes resonant scattering correctly for a large enough plasma frequency. For a very narrow h distribution (when delta theta >= 0.05 degrees), however, the effect of a fine structure in the wave spectrum becomes important. In this case, quasi-linear theory clearly fails in describing accurately electron scattering by fast magnetosonic waves. We also study the effect of high wave amplitudes on relativistic electron scattering. For typical conditions in the earth\textquoterights radiation belts, the quasi-linear approximation cannot accurately describe electron scattering for waves with averaged amplitudes > 300 pT. We discuss various applications of the obtained results for modeling electron dynamics in the radiation belts and in the Earth\textquoterights magnetotail. (C) 2015 AIP Publishing LLC.

Artemyev, A.; Mourenas, D.; Agapitov, O.; Krasnoselskikh, V.;

Published by: Physics of Plasmas      Published on: 06/2015

YEAR: 2015     DOI: 10.1063/1.4922061

chorus waves; CLUSTER SPACECRAFT; equatorial noise; MAGNETIC-FIELD; PLASMA; Quasi-linear diffusion; radiation belt electrons; RESONANT SCATTERING; Van Allen Probes; WHISTLER-MODE WAVES

Relativistic electron scattering by magnetosonic waves: Effects of discrete wave emission and high wave amplitudes

In this paper, we study relativistic electron scattering by fast magnetosonic waves. We compare results of test particle simulations and the quasi-linear theory for different spectra of waves to investigate how a fine structure of the wave emission can influence electron resonant scattering. We show that for a realistically wide distribution of wave normal angles theta (i.e., when the dispersion delta theta >= 0.5 degrees), relativistic electron scattering is similar for a wide wave spectrum and for a spectrum consisting in well-separated ion cyclotron harmonics. Comparisons of test particle simulations with quasi-linear theory show that for delta theta > 0.5 degrees, the quasi-linear approximation describes resonant scattering correctly for a large enough plasma frequency. For a very narrow h distribution (when delta theta >= 0.05 degrees), however, the effect of a fine structure in the wave spectrum becomes important. In this case, quasi-linear theory clearly fails in describing accurately electron scattering by fast magnetosonic waves. We also study the effect of high wave amplitudes on relativistic electron scattering. For typical conditions in the earth\textquoterights radiation belts, the quasi-linear approximation cannot accurately describe electron scattering for waves with averaged amplitudes > 300 pT. We discuss various applications of the obtained results for modeling electron dynamics in the radiation belts and in the Earth\textquoterights magnetotail. (C) 2015 AIP Publishing LLC.

Artemyev, A.; Mourenas, D.; Agapitov, O.; Krasnoselskikh, V.;

Published by: Physics of Plasmas      Published on: 06/2015

YEAR: 2015     DOI: 10.1063/1.4922061

chorus waves; CLUSTER SPACECRAFT; equatorial noise; MAGNETIC-FIELD; PLASMA; Quasi-linear diffusion; radiation belt electrons; RESONANT SCATTERING; Van Allen Probes; WHISTLER-MODE WAVES

A statistical study of EMIC waves observed by Cluster: 1. Wave properties

Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, as well as local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the MLT-L frame within a limited MLAT range. In this study, we present a statistical analysis of EMIC wave properties using ten years (2001\textendash2010) of data from Cluster, totaling 25,431 minutes of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. The statistical analysis is presented in two papers. This paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

Allen, R.; Zhang, J.; Kistler, L.; Spence, H.; Lin, R.; Klecker, B.; Dunlop, M.; e, Andr\; Jordanova, V.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021333

Cluster; EMIC waves; Magnetosphere; Shabansky orbits

A statistical study of EMIC waves observed by Cluster: 1. Wave properties

Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, as well as local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the MLT-L frame within a limited MLAT range. In this study, we present a statistical analysis of EMIC wave properties using ten years (2001\textendash2010) of data from Cluster, totaling 25,431 minutes of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. The statistical analysis is presented in two papers. This paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

Allen, R.; Zhang, J.; Kistler, L.; Spence, H.; Lin, R.; Klecker, B.; Dunlop, M.; e, Andr\; Jordanova, V.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021333

Cluster; EMIC waves; Magnetosphere; Shabansky orbits

A statistical study of EMIC waves observed by Cluster: 1. Wave properties

Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, as well as local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the MLT-L frame within a limited MLAT range. In this study, we present a statistical analysis of EMIC wave properties using ten years (2001\textendash2010) of data from Cluster, totaling 25,431 minutes of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. The statistical analysis is presented in two papers. This paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

Allen, R.; Zhang, J.; Kistler, L.; Spence, H.; Lin, R.; Klecker, B.; Dunlop, M.; e, Andr\; Jordanova, V.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021333

Cluster; EMIC waves; Magnetosphere; Shabansky orbits

A statistical study of EMIC waves observed by Cluster: 1. Wave properties

Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, as well as local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the MLT-L frame within a limited MLAT range. In this study, we present a statistical analysis of EMIC wave properties using ten years (2001\textendash2010) of data from Cluster, totaling 25,431 minutes of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. The statistical analysis is presented in two papers. This paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

Allen, R.; Zhang, J.; Kistler, L.; Spence, H.; Lin, R.; Klecker, B.; Dunlop, M.; e, Andr\; Jordanova, V.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021333

Cluster; EMIC waves; Magnetosphere; Shabansky orbits

A statistical study of EMIC waves observed by Cluster: 1. Wave properties

Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, as well as local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the MLT-L frame within a limited MLAT range. In this study, we present a statistical analysis of EMIC wave properties using ten years (2001\textendash2010) of data from Cluster, totaling 25,431 minutes of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. The statistical analysis is presented in two papers. This paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

Allen, R.; Zhang, J.; Kistler, L.; Spence, H.; Lin, R.; Klecker, B.; Dunlop, M.; e, Andr\; Jordanova, V.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021333

Cluster; EMIC waves; Magnetosphere; Shabansky orbits

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) appeared for over 4 hours at both Van Allen Probes, from late morning through local noon, when these spacecraft were outside the plasmapause, with densities ~5-20 cm-3. Waves were also observed by ground-based induction magnetometers in Antarctica (near dawn), Finland (near local noon), Russia (in the afternoon), and in Canada (from dusk to midnight). Ten passes of NOAA-POES and METOP satellites near the northern footpoint of the Van Allen Probes observed 30-80 keV subauroral proton precipitation, often over extended L shell ranges; other passes identified a narrow L-shell region of precipitation over Canada. Observations of relativistic electrons by the Van Allen Probes showed that the fluxes of more field-aligned and more energetic radiation belt electrons were reduced in response to both the emission over Canada and the more spatially extended emission associated with the compression, confirming the effectiveness of EMIC-induced loss processes for this event.

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) appeared for over 4 hours at both Van Allen Probes, from late morning through local noon, when these spacecraft were outside the plasmapause, with densities ~5-20 cm-3. Waves were also observed by ground-based induction magnetometers in Antarctica (near dawn), Finland (near local noon), Russia (in the afternoon), and in Canada (from dusk to midnight). Ten passes of NOAA-POES and METOP satellites near the northern footpoint of the Van Allen Probes observed 30-80 keV subauroral proton precipitation, often over extended L shell ranges; other passes identified a narrow L-shell region of precipitation over Canada. Observations of relativistic electrons by the Van Allen Probes showed that the fluxes of more field-aligned and more energetic radiation belt electrons were reduced in response to both the emission over Canada and the more spatially extended emission associated with the compression, confirming the effectiveness of EMIC-induced loss processes for this event.

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) appeared for over 4 hours at both Van Allen Probes, from late morning through local noon, when these spacecraft were outside the plasmapause, with densities ~5-20 cm-3. Waves were also observed by ground-based induction magnetometers in Antarctica (near dawn), Finland (near local noon), Russia (in the afternoon), and in Canada (from dusk to midnight). Ten passes of NOAA-POES and METOP satellites near the northern footpoint of the Van Allen Probes observed 30-80 keV subauroral proton precipitation, often over extended L shell ranges; other passes identified a narrow L-shell region of precipitation over Canada. Observations of relativistic electrons by the Van Allen Probes showed that the fluxes of more field-aligned and more energetic radiation belt electrons were reduced in response to both the emission over Canada and the more spatially extended emission associated with the compression, confirming the effectiveness of EMIC-induced loss processes for this event.

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) appeared for over 4 hours at both Van Allen Probes, from late morning through local noon, when these spacecraft were outside the plasmapause, with densities ~5-20 cm-3. Waves were also observed by ground-based induction magnetometers in Antarctica (near dawn), Finland (near local noon), Russia (in the afternoon), and in Canada (from dusk to midnight). Ten passes of NOAA-POES and METOP satellites near the northern footpoint of the Van Allen Probes observed 30-80 keV subauroral proton precipitation, often over extended L shell ranges; other passes identified a narrow L-shell region of precipitation over Canada. Observations of relativistic electrons by the Van Allen Probes showed that the fluxes of more field-aligned and more energetic radiation belt electrons were reduced in response to both the emission over Canada and the more spatially extended emission associated with the compression, confirming the effectiveness of EMIC-induced loss processes for this event.

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) appeared for over 4 hours at both Van Allen Probes, from late morning through local noon, when these spacecraft were outside the plasmapause, with densities ~5-20 cm-3. Waves were also observed by ground-based induction magnetometers in Antarctica (near dawn), Finland (near local noon), Russia (in the afternoon), and in Canada (from dusk to midnight). Ten passes of NOAA-POES and METOP satellites near the northern footpoint of the Van Allen Probes observed 30-80 keV subauroral proton precipitation, often over extended L shell ranges; other passes identified a narrow L-shell region of precipitation over Canada. Observations of relativistic electrons by the Van Allen Probes showed that the fluxes of more field-aligned and more energetic radiation belt electrons were reduced in response to both the emission over Canada and the more spatially extended emission associated with the compression, confirming the effectiveness of EMIC-induced loss processes for this event.

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) appeared for over 4 hours at both Van Allen Probes, from late morning through local noon, when these spacecraft were outside the plasmapause, with densities ~5-20 cm-3. Waves were also observed by ground-based induction magnetometers in Antarctica (near dawn), Finland (near local noon), Russia (in the afternoon), and in Canada (from dusk to midnight). Ten passes of NOAA-POES and METOP satellites near the northern footpoint of the Van Allen Probes observed 30-80 keV subauroral proton precipitation, often over extended L shell ranges; other passes identified a narrow L-shell region of precipitation over Canada. Observations of relativistic electrons by the Van Allen Probes showed that the fluxes of more field-aligned and more energetic radiation belt electrons were reduced in response to both the emission over Canada and the more spatially extended emission associated with the compression, confirming the effectiveness of EMIC-induced loss processes for this event.

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) appeared for over 4 hours at both Van Allen Probes, from late morning through local noon, when these spacecraft were outside the plasmapause, with densities ~5-20 cm-3. Waves were also observed by ground-based induction magnetometers in Antarctica (near dawn), Finland (near local noon), Russia (in the afternoon), and in Canada (from dusk to midnight). Ten passes of NOAA-POES and METOP satellites near the northern footpoint of the Van Allen Probes observed 30-80 keV subauroral proton precipitation, often over extended L shell ranges; other passes identified a narrow L-shell region of precipitation over Canada. Observations of relativistic electrons by the Van Allen Probes showed that the fluxes of more field-aligned and more energetic radiation belt electrons were reduced in response to both the emission over Canada and the more spatially extended emission associated with the compression, confirming the effectiveness of EMIC-induced loss processes for this event.

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) appeared for over 4 hours at both Van Allen Probes, from late morning through local noon, when these spacecraft were outside the plasmapause, with densities ~5-20 cm-3. Waves were also observed by ground-based induction magnetometers in Antarctica (near dawn), Finland (near local noon), Russia (in the afternoon), and in Canada (from dusk to midnight). Ten passes of NOAA-POES and METOP satellites near the northern footpoint of the Van Allen Probes observed 30-80 keV subauroral proton precipitation, often over extended L shell ranges; other passes identified a narrow L-shell region of precipitation over Canada. Observations of relativistic electrons by the Van Allen Probes showed that the fluxes of more field-aligned and more energetic radiation belt electrons were reduced in response to both the emission over Canada and the more spatially extended emission associated with the compression, confirming the effectiveness of EMIC-induced loss processes for this event.

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Weak Kinetic Alfv\ en Waves Turbulence during the November 14th 2012 geomagnetic storm: Van Allen Probes observations

n the dawn sector, L~ 5.5 and MLT~4-7, from 01:30 to 06:00 UT during the November 14th 2012 geomagnetic storm, both Van Allen Probes observed an alternating sequence of locally quiet and disturbed intervals with two strikingly different power fluctuation levels and magnetic field orientations: either small (~10-2 nT2) total power with strong GSM Bx and weak By, or large (~10 nT2) total power with weak Bx, and strong By and Bz components. During both kinds of intervals the fluctuations occur in the vicinity of the local ion gyro-frequencies (0.01-10 Hz) in the spacecraft frame, propagate oblique to the magnetic field, (θ ~ 60\textdegree) and have magnetic compressibility C = |δB|||/|δB⊥| \~ 1, where δB|| (δB⊥) are the average amplitudes of the fluctuations parallel (perpendicular) to the mean field. Electric field fluctuations are present whenever the magnetic field is disturbed, and large electric field fluctuations follow the same pattern for quiet and disturbed intervals. Magnetic frequency power spectra at both spacecraft correspond to steep power-laws \~ f \textendashα with 4 < α < 5 for f ≲ 2 Hz, and 1.1 < α < 1.7 for f ≲ 2 Hz, spectral profiles that are consistent with weak Kinetic Alfv\ en Waves (KAW) turbulence. Electric power is larger than magnetic power for all frequencies above 0.1 Hz, and the ratio increases with increasing frequency. Vlasov linear analysis is consistent with the presence of compressive KAW with k⊥ρi ≲ 1, right-handed polarization and positive magnetic helicity, in the plasma frame, considering a multi-ion plasma. All these results suggest the presence of weak KAW turbulence which dissipates the energy associated with the intermittent sudden changes in the magnetic field during the main phase of the storm.

Moya, Pablo.; Pinto, V\; Vi\~nas, Adolfo; Sibeck, David; Kurth, William; Hospodarsky, George; Wygant, John;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2014JA020281

Kinetic Alfven Waves; Magnetic Storms; Radiation belts; Van Allen Probes

3D test-particle simulation of the 17-18 March, 2013 CME-shock driven storm

D test-particle simulation of energetic electrons (hundreds of keV to MeV), including both an initially trapped population and continuously injected population, driven by the Lyon-Fedder-Mobarry (LFM) global MHD model coupled with Magnetosphere-Ionosphere Coupler/Solver (MIX) boundary conditions, is performed for the March 17, 2013 storm. The electron trajectories are calculated and weighted using the ESA model for electron flux vs. energy and L. The simulation captures the flux dropout at both GOES-13 and GOES-15 locations after a strong CME-shock arrival which produced a Dst=-132 nT storm, and recovery to the pre-storm value later, consistent with GOES satellite measurements. This study provides the first 3D test-particle simulation combining the trapped and injected populations. The result demonstrates that including both populations in the simulation is essential to study the dynamics of the outer radiation belt over the typical day-long timescale of ring current development, main phase and early recovery phase.

Li, Zhao; Hudson, Mary; Kress, Brian; Paral, Jan;

Published by: Geophysical Research Letters      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015GL064627

17 March; 2013; CME-shock driven storm; Radiation belt; test-particle simulation

A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes MagEIS electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30-500 keV) and in regions of geospace where multi-MeV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

Claudepierre, S.; O\textquoterightBrien, T.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Looper, M.; Mazur, J.; Mulligan, T.; Spence, H.; Reeves, G.; Friedel, R.; Henderson, M.; Larsen, B.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021171

Background contamination; Inner radiation belt; outer radiation belt; Particle measurements; Radiation belt; Spacecraft engineering; Van Allen Probes

A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes MagEIS electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30-500 keV) and in regions of geospace where multi-MeV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

Claudepierre, S.; O\textquoterightBrien, T.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Looper, M.; Mazur, J.; Mulligan, T.; Spence, H.; Reeves, G.; Friedel, R.; Henderson, M.; Larsen, B.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021171

Background contamination; Inner radiation belt; outer radiation belt; Particle measurements; Radiation belt; Spacecraft engineering; Van Allen Probes

A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes MagEIS electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30-500 keV) and in regions of geospace where multi-MeV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

Claudepierre, S.; O\textquoterightBrien, T.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Looper, M.; Mazur, J.; Mulligan, T.; Spence, H.; Reeves, G.; Friedel, R.; Henderson, M.; Larsen, B.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021171

Background contamination; Inner radiation belt; outer radiation belt; Particle measurements; Radiation belt; Spacecraft engineering; Van Allen Probes

A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes MagEIS electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30-500 keV) and in regions of geospace where multi-MeV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

Claudepierre, S.; O\textquoterightBrien, T.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Looper, M.; Mazur, J.; Mulligan, T.; Spence, H.; Reeves, G.; Friedel, R.; Henderson, M.; Larsen, B.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021171

Background contamination; Inner radiation belt; outer radiation belt; Particle measurements; Radiation belt; Spacecraft engineering; Van Allen Probes

A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes MagEIS electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30-500 keV) and in regions of geospace where multi-MeV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

Claudepierre, S.; O\textquoterightBrien, T.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Looper, M.; Mazur, J.; Mulligan, T.; Spence, H.; Reeves, G.; Friedel, R.; Henderson, M.; Larsen, B.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021171

Background contamination; Inner radiation belt; outer radiation belt; Particle measurements; Radiation belt; Spacecraft engineering; Van Allen Probes

A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes MagEIS electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30-500 keV) and in regions of geospace where multi-MeV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

Claudepierre, S.; O\textquoterightBrien, T.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Looper, M.; Mazur, J.; Mulligan, T.; Spence, H.; Reeves, G.; Friedel, R.; Henderson, M.; Larsen, B.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021171

Background contamination; Inner radiation belt; outer radiation belt; Particle measurements; Radiation belt; Spacecraft engineering; Van Allen Probes

A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes MagEIS electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30-500 keV) and in regions of geospace where multi-MeV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

Claudepierre, S.; O\textquoterightBrien, T.; Blake, J.; Fennell, J.; Roeder, J.; Clemmons, J.; Looper, M.; Mazur, J.; Mulligan, T.; Spence, H.; Reeves, G.; Friedel, R.; Henderson, M.; Larsen, B.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2015

YEAR: 2015     DOI: 10.1002/2015JA021171

Background contamination; Inner radiation belt; outer radiation belt; Particle measurements; Radiation belt; Spacecraft engineering; Van Allen Probes