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Title: The Characteristic Pitch Angle Distributions of 1 eV to 600 keV Protons Near the Equator Based On Van Allen Probes Observations

Abstract

Understanding the source and loss processes of various plasma populations is greatly aided by having accurate knowledge of their pitch angle distributions (PADs). Here we statistically analyze ~1 eV to 600 keV hydrogen (H+) PADs near the geomagnetic equator in the inner magnetosphere based on Van Allen Probes measurements, to comprehensively investigate how the H+ PADs vary with different energies, magnetic local times (MLTs), L shells, and geomagnetic conditions. Our survey clearly indicates four distinct populations with different PADs: a pancake distribution of the plasmaspheric H+ at low L shells except for dawn sector; a bidirectional field-aligned distribution of the warm plasma cloak; pancake or isotropic distributions of ring current H+; radiation belt particles show pancake, butterfly, and isotropic distributions depending on their energy, MLT, and L shell. Meanwhile, the pancake distribution of ring current H+ moves to lower energies as shell increases, which is primarily caused by adiabatic transport. Furthermore, energetic H+ (>10 keV) PADs become more isotropic following the substorm injections, indicating wave-particle interactions. The radiation belt H+ butterfly distributions are identified in a narrow energy range of 100 < E < 400 keV at large L ( L > 5), which are less significant during quiet timesmore » and extend from dusk to dawn sector through midnight during substorms. In conclusion, the different PADs near the equator provide clues of the underlying physical processes that produce the dynamics of these different populations.« less

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [2];  [4]; ORCiD logo [5]; ORCiD logo [5]; ORCiD logo [6]; ORCiD logo [7]; ORCiD logo [8]; ORCiD logo [9]; ORCiD logo [9]; ORCiD logo [10]
  1. UCLA, Los Angeles, CA (United States); Univ. Corp. for Atmospheric Research, Boulder, CO (United States)
  2. UCLA, Los Angeles, CA (United States)
  3. UCLA, Los Angeles, CA (United States); Boston, Univ., Boston, MA (United States)
  4. Vanderbilt Univ., Nashville, TN (United States)
  5. New Jersey Institute of Technology, Newark, NJ (United States)
  6. Shandong Univ., Weihai (China)
  7. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico Consortium, Los Alamos, NM (United States)
  8. Univ. of New Hampshire, Durham, NH (United States)
  9. The Johns Hopkins Univ. Applied Physics Lab., Laurel, MD (United States)
  10. Univ. of Iowa, Iowa City, IA (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
National Aeronautic and Space Administration (NASA); USDOE
OSTI Identifier:
1415430
Report Number(s):
LA-UR-17-30360
Journal ID: ISSN 2169-9380; TRN: US1800823
Grant/Contract Number:  
AC52-06NA25396
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Space Physics
Additional Journal Information:
Journal Volume: 122; Journal Issue: 9; Journal ID: ISSN 2169-9380
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; Heliospheric and Magnetospheric Physics; H+ pitch angle distributions; plasmaspheric H+; ring current; warm plasma cloak; radiation belt H+; bidirectional field aligned

Citation Formats

Yue, Chao, Bortnik, Jacob, Thorne, Richard M., Ma, Qianli, An, Xin, Chappell, C. R., Gerrard, Andrew J., Lanzerotti, Louis J., Shi, Quanqi, Reeves, Geoffrey D., Spence, Harlan E., Mitchell, Donald G., Gkioulidou, Matina, and Kletzing, Craig A. The Characteristic Pitch Angle Distributions of 1 eV to 600 keV Protons Near the Equator Based On Van Allen Probes Observations. United States: N. p., 2017. Web. doi:10.1002/2017JA024421.
Yue, Chao, Bortnik, Jacob, Thorne, Richard M., Ma, Qianli, An, Xin, Chappell, C. R., Gerrard, Andrew J., Lanzerotti, Louis J., Shi, Quanqi, Reeves, Geoffrey D., Spence, Harlan E., Mitchell, Donald G., Gkioulidou, Matina, & Kletzing, Craig A. The Characteristic Pitch Angle Distributions of 1 eV to 600 keV Protons Near the Equator Based On Van Allen Probes Observations. United States. doi:10.1002/2017JA024421.
Yue, Chao, Bortnik, Jacob, Thorne, Richard M., Ma, Qianli, An, Xin, Chappell, C. R., Gerrard, Andrew J., Lanzerotti, Louis J., Shi, Quanqi, Reeves, Geoffrey D., Spence, Harlan E., Mitchell, Donald G., Gkioulidou, Matina, and Kletzing, Craig A. Thu . "The Characteristic Pitch Angle Distributions of 1 eV to 600 keV Protons Near the Equator Based On Van Allen Probes Observations". United States. doi:10.1002/2017JA024421. https://www.osti.gov/servlets/purl/1415430.
@article{osti_1415430,
title = {The Characteristic Pitch Angle Distributions of 1 eV to 600 keV Protons Near the Equator Based On Van Allen Probes Observations},
author = {Yue, Chao and Bortnik, Jacob and Thorne, Richard M. and Ma, Qianli and An, Xin and Chappell, C. R. and Gerrard, Andrew J. and Lanzerotti, Louis J. and Shi, Quanqi and Reeves, Geoffrey D. and Spence, Harlan E. and Mitchell, Donald G. and Gkioulidou, Matina and Kletzing, Craig A.},
abstractNote = {Understanding the source and loss processes of various plasma populations is greatly aided by having accurate knowledge of their pitch angle distributions (PADs). Here we statistically analyze ~1 eV to 600 keV hydrogen (H+) PADs near the geomagnetic equator in the inner magnetosphere based on Van Allen Probes measurements, to comprehensively investigate how the H+ PADs vary with different energies, magnetic local times (MLTs), L shells, and geomagnetic conditions. Our survey clearly indicates four distinct populations with different PADs: a pancake distribution of the plasmaspheric H+ at low L shells except for dawn sector; a bidirectional field-aligned distribution of the warm plasma cloak; pancake or isotropic distributions of ring current H+; radiation belt particles show pancake, butterfly, and isotropic distributions depending on their energy, MLT, and L shell. Meanwhile, the pancake distribution of ring current H+ moves to lower energies as shell increases, which is primarily caused by adiabatic transport. Furthermore, energetic H+ (>10 keV) PADs become more isotropic following the substorm injections, indicating wave-particle interactions. The radiation belt H+ butterfly distributions are identified in a narrow energy range of 100 < E < 400 keV at large L (L > 5), which are less significant during quiet times and extend from dusk to dawn sector through midnight during substorms. In conclusion, the different PADs near the equator provide clues of the underlying physical processes that produce the dynamics of these different populations.},
doi = {10.1002/2017JA024421},
journal = {Journal of Geophysical Research. Space Physics},
number = 9,
volume = 122,
place = {United States},
year = {2017},
month = {8}
}

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Works referenced in this record:

The role of drift orbit bifurcations in energization and loss of electrons in the outer radiation belt: THE ROLE OF DRIFT ORBIT BIFURCATIONS
journal, September 2011

  • Ukhorskiy, A. Y.; Sitnov, M. I.; Millan, R. M.
  • Journal of Geophysical Research: Space Physics, Vol. 116, Issue A9
  • DOI: 10.1029/2011JA016623

Modeling the propagation characteristics of chorus using CRRES suprathermal electron fluxes: PROPAGATION CHARACTERISTICS OF CHORUS
journal, August 2007

  • Bortnik, J.; Thorne, R. M.; Meredith, N. P.
  • Journal of Geophysical Research: Space Physics, Vol. 112, Issue A8
  • DOI: 10.1029/2006JA012237

Drift-shell splitting of energetic ions injected at pseudo-substorm onsets
journal, October 1997

  • Takahashi, Kazue; Anderson, Brian J.; Ohtani, Shin-ichi
  • Journal of Geophysical Research: Space Physics, Vol. 102, Issue A10
  • DOI: 10.1029/97JA01870

Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes
journal, February 2016

  • Sarno‐Smith, Lois K.; Larsen, Brian A.; Skoug, Ruth M.
  • Space Weather, Vol. 14, Issue 2
  • DOI: 10.1002/2015SW001345

Effects of charge exchange involving H and H+ in the upper atmosphere
journal, September 1978


High-Resolution Energetic Particle Measurements at 6.6 R E , 3. Low-Energy Electron Anisotropies and Short-Term Substorm Predictions
journal, January 1978

  • Baker, D. N.; Higbie, P. R.; Hones, E. W.
  • Journal of Geophysical Research, Vol. 83, Issue A10
  • DOI: 10.1029/JA083iA10p04863

Empirical modeling of the quiet time nightside magnetosphere
journal, January 1994

  • Lui, A. T. Y.; Spence, H. E.; Stern, D. P.
  • Journal of Geophysical Research, Vol. 99, Issue A1
  • DOI: 10.1029/93JA02647

Coulomb lifetime of the ring current ions with time varying plasmasphere
journal, April 1998

  • Ebihara, Yusuke; Ejiri, Masaki; Miyaoka, Hiroshi
  • Earth, Planets and Space, Vol. 50, Issue 4
  • DOI: 10.1186/BF03352123

The contribution of ion-cyclotron waves to electron heating and SAR-arc excitation near the storm-time plasmapause
journal, February 1992

  • Thorne, Richard M.; Horne, Richard B.
  • Geophysical Research Letters, Vol. 19, Issue 4
  • DOI: 10.1029/92GL00089

Substorm-associated particle boundary motion at synchronous orbit
journal, November 1976

  • Walker, R. J.; Erickson, K. N.; Swanson, R. L.
  • Journal of Geophysical Research, Vol. 81, Issue 31
  • DOI: 10.1029/JA081i031p05541

The ionosphere as a fully adequate source of plasma for the Earth's magnetosphere
journal, January 1987

  • Chappell, C. R.; Moore, T. E.; Waite, J. H.
  • Journal of Geophysical Research, Vol. 92, Issue A6
  • DOI: 10.1029/JA092iA06p05896

Lifetime of ring current particles due to coulomb collisions in the plasmasphere
journal, January 1991

  • Fok, M. -C.; Kozyra, J. U.; Nagy, A. F.
  • Journal of Geophysical Research, Vol. 96, Issue A5
  • DOI: 10.1029/90JA02620

Evolution of energetic electron pitch angle distributions during storm time electron acceleration to megaelectronvolt energies
journal, January 2003


Proton ring current pitch angle distributions: Comparison of simulations with CRRES observations
journal, August 1999

  • Chen, Margaret W.; Roeder, James L.; Fennell, Joseph F.
  • Journal of Geophysical Research: Space Physics, Vol. 104, Issue A8
  • DOI: 10.1029/1999JA900142

Pitch-angle diffusion of radiation belt electrons within the plasmasphere
journal, July 1972

  • Lyons, Lawrence R.; Thorne, Richard Mansergh; Kennel, Charles F.
  • Journal of Geophysical Research, Vol. 77, Issue 19
  • DOI: 10.1029/JA077i019p03455

The quiet time structure of energetic (35-560 keV) radiation belt electrons
journal, March 1975


The storm and poststorm evolution of energetic (35-560 keV) radiation belt electron distributions
journal, October 1975


The Electric Field and Waves Instruments on the Radiation Belt Storm Probes Mission
journal, October 2013


Parasitic pitch angle diffusion of radiation belt particles by ion cyclotron waves
journal, October 1972

  • Lyons, Lawrence R.; Thorne, Richard Mansergh
  • Journal of Geophysical Research, Vol. 77, Issue 28
  • DOI: 10.1029/JA077i028p05608

Magnetospheric plasma pressures in the midnight meridian: Observations from 2.5 to 35 R E
journal, January 1989

  • Spence, Harlan E.; Kivelson, Margaret G.; Walker, Raymond J.
  • Journal of Geophysical Research, Vol. 94, Issue A5
  • DOI: 10.1029/JA094iA05p05264

Electron pitch angle diffusion by electrostatic electron cyclotron harmonic waves: The origin of pancake distributions
journal, March 2000

  • Horne, Richard B.; Thorne, Richard M.
  • Journal of Geophysical Research: Space Physics, Vol. 105, Issue A3
  • DOI: 10.1029/1999JA900447

Global distributions of suprathermal electrons observed on THEMIS and potential mechanisms for access into the plasmasphere: ELECTRON ACCESS INTO THE PLASMASPHERE
journal, December 2010

  • Li, W.; Thorne, R. M.; Bortnik, J.
  • Journal of Geophysical Research: Space Physics, Vol. 115, Issue A12
  • DOI: 10.1029/2010JA015687

A statistical study of EMIC wave-associated He + energization in the outer magnetosphere: Cluster/CODIF observations : HE
journal, November 2011

  • Zhang, J. -C.; Kistler, L. M.; Mouikis, C. G.
  • Journal of Geophysical Research: Space Physics, Vol. 116, Issue A11
  • DOI: 10.1029/2011JA016690

On the adiabatic motion of energetic particles in a model magnetosphere
journal, February 1967


The proton ring current and its interaction with the plasmapause: Storm recovery phase
journal, October 1974


Transitional behavior of different energy protons based on Van Allen Probes observations: Proton Transitional Behavior
journal, January 2017

  • Yue, Chao; Bortnik, Jacob; Chen, Lunjin
  • Geophysical Research Letters, Vol. 44, Issue 2
  • DOI: 10.1002/2016GL071324

Helium, Oxygen, Proton, and Electron (HOPE) Mass Spectrometer for the Radiation Belt Storm Probes Mission
journal, March 2013


Further aspects of the proton ring current interaction with the plasmapause: Main and recovery phases
journal, November 1974


Observations of the warm plasma cloak and an explanation of its formation in the magnetosphere: WARM PLASMA CLOAK
journal, September 2008

  • Chappell, C. R.; Huddleston, M. M.; Moore, T. E.
  • Journal of Geophysical Research: Space Physics, Vol. 113, Issue A9
  • DOI: 10.1029/2007JA012945

The adequacy of the ionospheric source in supplying magnetospheric plasma
journal, April 2000

  • Chappell, C. R.; Giles, B. L.; Moore, T. E.
  • Journal of Atmospheric and Solar-Terrestrial Physics, Vol. 62, Issue 6
  • DOI: 10.1016/S1364-6826(00)00021-3

An examination of the process and magnitude of ionospheric plasma supply to the magnetosphere
journal, January 2005

  • Huddleston, M. M.; Chappell, C. R.; Delcourt, D. C.
  • Journal of Geophysical Research, Vol. 110, Issue A12
  • DOI: 10.1029/2004JA010401

The transport of plasma sheet material from the distant tail to geosynchronous orbit
journal, September 1998

  • Borovsky, Joseph E.; Thomsen, Michelle F.; Elphic, Richard C.
  • Journal of Geophysical Research: Space Physics, Vol. 103, Issue A9
  • DOI: 10.1029/97JA03144

Transverse eV ion heating by random electric field fluctuations in the plasmasphere
journal, February 2017

  • Artemyev, A. V.; Mourenas, D.; Agapitov, O. V.
  • Physics of Plasmas, Vol. 24, Issue 2
  • DOI: 10.1063/1.4976713

Landau damping of magnetospherically reflected whistlers
journal, January 1994

  • Thorne, Richard M.; Horne, Richard B.
  • Journal of Geophysical Research, Vol. 99, Issue A9
  • DOI: 10.1029/94JA01006

Static magnetic field models consistent with nearly isotropic plasma pressure
journal, August 1987

  • Spence, Harlan E.; Kivelson, Margaret G.; Walker, Raymond J.
  • Geophysical Research Letters, Vol. 14, Issue 8
  • DOI: 10.1029/GL014i008p00872

Magnetic field drift shell splitting: Cause of unusual dayside particle pitch angle distributions during storms and substorms
journal, January 1987

  • Sibeck, D. G.; McEntire, R. W.; Lui, A. T. Y.
  • Journal of Geophysical Research, Vol. 92, Issue A12
  • DOI: 10.1029/JA092iA12p13485

Electron pitch angle distributions throughout the magnetosphere as observed on Ogo 5
journal, March 1973

  • West, H. I.; Buck, R. M.; Walton, J. R.
  • Journal of Geophysical Research, Vol. 78, Issue 7
  • DOI: 10.1029/JA078i007p01064

Review of radiation belt relativistic electron losses
journal, March 2007


Recent findings on angular distributions of dayside ring current energetic ions
journal, January 1990

  • Lui, A. T. Y.; McEntire, R. W.; Sibeck, D. G.
  • Journal of Geophysical Research, Vol. 95, Issue A12
  • DOI: 10.1029/JA095iA12p20839

Science Objectives and Rationale for the Radiation Belt Storm Probes Mission
journal, September 2012


Outward radial diffusion driven by losses at magnetopause
journal, January 2006

  • Shprits, Y. Y.; Thorne, R. M.; Friedel, R.
  • Journal of Geophysical Research, Vol. 111, Issue A11
  • DOI: 10.1029/2006JA011657