@article{d55a3048312d47028878afa35a441ddb,
title = "The Composition of Plasma inside Geostationary Orbit Based on Van Allen Probes Observations",
abstract = "The composition of the inner magnetosphere is of great importance for determining the plasma pressure and thus the currents and magnetic field configuration. In this study, we perform a statistical survey of equatorial plasma pressure distributions and investigate the relative contributions of ions and electron with different energies inside of geostationary orbit under two auroral electrojet levels based on over 60 months of observations from the Helium, Oxygen, Proton, and Electron and Radiation Belt Storm Probes Ion Composition Experiment mass spectrometers onboard Van Allen Probes. We find that the total and partial pressures of different species increase significantly at high auroral electrojet levels with hydrogen pressure being dominant in the plasmasphere. The pressures of the heavy ions and electrons increase outside the plasmapause and develop a strong dawn-dusk asymmetry with ion pressures peaking at dusk and electron pressure peaking at dawn. In addition, ring current hydrogen with energies ranging from 50 keV up to several hundred keV is the dominant component of plasma pressure during both quiet (>90%) and active times (>60%), while oxygen with 10 < E < 50 keV and electrons with 0.1 < E < 40 keV become important during active times contributing more than 25% and 20% on the nightside, respectively, while the helium contribution is generally small. The results presented in this study provide a global picture of the equatorial plasma pressure distributions and the associated contributions from different species with different energy ranges, which advance our knowledge of wave generation and provide models with a systematic baseline of plasma composition.",
keywords = "ion composition, plasma pressure, plasmapause",
author = "Chao Yue and Jacob Bortnik and Wen Li and Qianli Ma and Matina Gkioulidou and Reeves, {Geoffrey D.} and Wang, {Chih Ping} and Thorne, {Richard M.} and Lui, {Anthony T.Y.} and Andrew Gerrard and Spence, {Harlan E.} and Mitchell, {Donald G.}",
note = "Funding Information: This work was supported by NASA LWS grant NNX14AN85G and NASA HTIDeS NNX16AG21G. Wen Li would like to acknowledge NASA grants NNX15AI96G and NNX17AG07G. Gkioulidou was supported by JHU/APL subcontract 131803 to the New Jersey Institute of Technology under NASA Prime contract NNN06AA01C. We acknowledge use of Van Allen Probes data of the Level 3 HOPE omni- and unidimensional particle flux data obtained from the RBSP-ECT website (rbsp-ect.lanl.gov/data_pub/rbspb/hope/level3/PA/), made publicly available through NASA prime contract number NAS5-01072; the Level 3 omni- and uni-dimensional RBSPICE particle flux data obtained from the RBSPICE website (http://rbspicea.ftecs.com/Level_3PAP/); and the level 3 high-frequency receiver data obtained from the RBSP Electric and Magnetic Field Instrument Suite and Integrated Science website (emfisis.physics.uiowa.edu/Flight/RBSP-B/L3). We thank the Space Physics Data Facility at the NASA Goddard Space Flight Center for providing the OMNI data (ftp://spdf.gsfc.nasa.gov/pub/data/omni/omni_cdaweb/). Funding Information: This work was supported by NASA LWS grant NNX14AN85G and NASA HTIDeS NNX16AG21G. Wen Li would like to acknowledge NASA grants NNX15AI96G and NNX17AG07G. Gkioulidou was supported by JHU/APL subcontract 131803 to the New Jersey Institute of Technology under NASA Prime contract NNN06AA01C. We acknowledge use of Van Allen Probes data of the Level 3 HOPE omni-and unidimensional particle flux data obtained from the RBSP-ECT website (rbsp-ect.lanl.gov/ data_pub/rbspb/hope/level3/PA/), made publicly available through NASA prime contract number NAS5-01072; the Level 3 omni-and uni-dimensional RBSPICE particle flux data obtained from the RBSPICE website (http://rbspicea. ftecs.com/Level_3PAP/); and the level 3 high-frequency receiver data obtained from the RBSP Electric and Magnetic Field Instrument Suite and Integrated Science website (emfisis.physics.uiowa. edu/Flight/RBSP-B/L3). We thank the Space Physics Data Facility at the NASA Goddard Space Flight Center for providing the OMNI data (ftp://spdf. gsfc.nasa.gov/pub/data/omni/omni_ cdaweb/). Publisher Copyright: {\textcopyright}2018. American Geophysical Union. All Rights Reserved.",
year = "2018",
month = aug,
doi = "10.1029/2018JA025344",
language = "English (US)",
volume = "123",
pages = "6478--6493",
journal = "Journal of Geophysical Research: Space Physics",
issn = "2169-9380",
number = "8",
}