Found 4 entries in the Bibliography.

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TWINS Observations of the Dynamics of Ring Currents Ion Spectra on 17th March and 7th October 2015

Direct comparisons between RBSP (Van Allen Probes or Radiation Belt Storm Probes) and TWINS (Two Wide-angle Imaging Neutral-atom Spectrometers) for the main phase of two storms, 17th March and 7th October 2015, showed agreement between the in–situ ion measurements and the ion spectra from the deconvolved energetic neutral atom (ENA) measurements, except when O+ ions were significant. Spatial evolution of individual energy peaks in the ion spectra are studied using TWINS data. O+ ions are seen to result in intense peaks at ...

Shekhar, S.; Perez, J.; Ferradas, C.;

YEAR: 2020     DOI:

Ring Currents; Magnetosphere; energy dependent drift; ion nose; Substorm Injections; Ion Spectra; Van Allen Probes


Statistical investigation of the efficiency of EMIC waves in precipitating relativistic electrons

Electromagnetic ion cyclotron (EMIC) waves have been proposed to cause Relativistic Electron Precipitation (REP). In our study, we carry out 4 years of analysis from 2013 to 2016, with relativistic electron precipitation spikes obtained from POES satellites and EMIC waves observation from Van Allen Probes. Among the 473 coincidence events when POES satellites go through the region conjugate to EMIC wave activity, only 127 are associated with REP. Additionally, the coincidence occurrence rate is about 10\% higher than the ran ...

Qin, Murong; Hudson, Mary; Millan, Mary; Woodger, Leslie; Shekhar, Sapna;

YEAR: 2018     DOI: 10.1029/2018JA025419

causally related; coincidence occurrence rate; efficiency; EMIC wave; random coincidence occurrence rate; relativistic electron precipitation; Van Allen Probes


A Statistical Study of the Spatial Extent of Relativistic Electron Precipitation with Polar Orbiting Environmental Satellites.

Relativistic Electron Precipitation (REP) in the atmosphere can contribute significantly to electron loss from the outer radiation belts. In order to estimate the contribution to this loss, it is important to estimate the spatial extent of the precipitation region. We observed REP with the zenith pointing (0o) Medium Energy Proton Electron Detector (MEPED) on board Polar Orbiting Environmental Satellites (POES), for 15 years (2000-2014) and used both single and multi satellite measurements to estimate an average extent of th ...

Shekhar, Sapna; Millan, Robyn; Smith, David;

YEAR: 2017     DOI: 10.1002/2017JA024716

Magnetosphere; precipitation; Radiation belts; relativistic electrons; spatial scale of REP; Van Allen Probes; wave particle scattering

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

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

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

YEAR: 2017     DOI: 10.1002/2016JA023752

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