skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The influences of solar wind pressure and interplanetary magnetic field on global magnetic field and outer radiation belt electrons

Abstract

Using the Van Allen Probe in situ measured magnetic field and electron data, we examine the solar wind dynamic pressure and interplanetary magnetic field (IMF) effects on global magnetic field and outer radiation belt relativistic electrons (≥1.8 MeV). The dynamic pressure enhancements (>2 nPa) cause the dayside magnetic field increase and the nightside magnetic field reduction, whereas the large southward IMFs (Bz-IMF < –2nT) mainly lead to the decrease of the nightside magnetic field. In the dayside increased magnetic field region (magnetic local time (MLT) ~ 06:00–18:00, and L > 4), the pitch angles of relativistic electrons are mainly pancake distributions with a flux peak around 90° (corresponding anisotropic index A > 0.1), and the higher-energy electrons have stronger pancake distributions (the larger A), suggesting that the compression-induced betatron accelerations enhance the dayside pancake distributions. However, in the nighttime decreased magnetic field region (MLT ~ 18:00–06:00, and L ≥ 5), the pitch angles of relativistic electrons become butterfly distributions with two flux peaks around 45° and 135° (A < 0). The spatial range of the nighttime butterfly distributions is almost independent of the relativistic electron energy, but it depends on the magnetic field day-night asymmetry and the interplanetary conditions. Themore » dynamic pressure enhancements can make the nighttime butterfly distribution extend inward. The large southward IMFs can also lead to the azimuthal expansion of the nighttime butterfly distributions. As a result, these variations are consistent with the drift shell splitting and/or magnetopause shadowing effect.« less

Authors:
 [1];  [1];  [1]; ORCiD logo [2];  [3];  [4]
  1. Beihang Univ., Beijing (China)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Univ. of Colorado, Boulder, CO (United States)
  4. Univ. of New Hampshire, Durham, NH (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
National Aeronautics and Space Administration (NASA); USDOE
OSTI Identifier:
1304818
Report Number(s):
LA-UR-16-23137
Journal ID: ISSN 0094-8276
Grant/Contract Number:  
AC52-06NA25396
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Geophysical Research Letters
Additional Journal Information:
Journal Volume: 43; Journal Issue: 14; Journal ID: ISSN 0094-8276
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; Heliospheric and Magnetospheric Physics

Citation Formats

Yu, J., Li, L. Y., Cao, J. B., Reeves, Geoffrey D., Baker, D. N., and Spence, H. The influences of solar wind pressure and interplanetary magnetic field on global magnetic field and outer radiation belt electrons. United States: N. p., 2016. Web. doi:10.1002/2016GL069029.
Yu, J., Li, L. Y., Cao, J. B., Reeves, Geoffrey D., Baker, D. N., & Spence, H. The influences of solar wind pressure and interplanetary magnetic field on global magnetic field and outer radiation belt electrons. United States. https://doi.org/10.1002/2016GL069029
Yu, J., Li, L. Y., Cao, J. B., Reeves, Geoffrey D., Baker, D. N., and Spence, H. 2016. "The influences of solar wind pressure and interplanetary magnetic field on global magnetic field and outer radiation belt electrons". United States. https://doi.org/10.1002/2016GL069029. https://www.osti.gov/servlets/purl/1304818.
@article{osti_1304818,
title = {The influences of solar wind pressure and interplanetary magnetic field on global magnetic field and outer radiation belt electrons},
author = {Yu, J. and Li, L. Y. and Cao, J. B. and Reeves, Geoffrey D. and Baker, D. N. and Spence, H.},
abstractNote = {Using the Van Allen Probe in situ measured magnetic field and electron data, we examine the solar wind dynamic pressure and interplanetary magnetic field (IMF) effects on global magnetic field and outer radiation belt relativistic electrons (≥1.8 MeV). The dynamic pressure enhancements (>2 nPa) cause the dayside magnetic field increase and the nightside magnetic field reduction, whereas the large southward IMFs (Bz-IMF < –2nT) mainly lead to the decrease of the nightside magnetic field. In the dayside increased magnetic field region (magnetic local time (MLT) ~ 06:00–18:00, and L > 4), the pitch angles of relativistic electrons are mainly pancake distributions with a flux peak around 90° (corresponding anisotropic index A > 0.1), and the higher-energy electrons have stronger pancake distributions (the larger A), suggesting that the compression-induced betatron accelerations enhance the dayside pancake distributions. However, in the nighttime decreased magnetic field region (MLT ~ 18:00–06:00, and L ≥ 5), the pitch angles of relativistic electrons become butterfly distributions with two flux peaks around 45° and 135° (A < 0). The spatial range of the nighttime butterfly distributions is almost independent of the relativistic electron energy, but it depends on the magnetic field day-night asymmetry and the interplanetary conditions. The dynamic pressure enhancements can make the nighttime butterfly distribution extend inward. The large southward IMFs can also lead to the azimuthal expansion of the nighttime butterfly distributions. As a result, these variations are consistent with the drift shell splitting and/or magnetopause shadowing effect.},
doi = {10.1002/2016GL069029},
url = {https://www.osti.gov/biblio/1304818}, journal = {Geophysical Research Letters},
issn = {0094-8276},
number = 14,
volume = 43,
place = {United States},
year = {Thu Jul 28 00:00:00 EDT 2016},
month = {Thu Jul 28 00:00:00 EDT 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 18 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Modeling the dynamics of the inner magnetosphere during strong geomagnetic storms
journal, January 2005


Large and sharp solar wind dynamic pressure variations as a source of geomagnetic field disturbances at the geosynchronous orbit
journal, January 2005


Magnetospheric configuration and energetic particle effects associated with a SSC: A case study of the CDAW 6 Event on March 22, 1979
journal, January 1986


The Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) on RBSP
journal, June 2013


Comparison of geosynchronous energetic particle flux responses to solar wind dynamic pressure enhancements and substorms: GEOSYNCHRONOUS PARTICLES AND DYNAMIC PRESSURE
journal, September 2005


Simulation of the prompt energization and transport of radiation belt particles during the March 24, 1991 SSC
journal, November 1993


Wave-driven butterfly distribution of Van Allen belt relativistic electrons
journal, October 2015


Storm-time configuration of the inner magnetosphere: Lyon-Fedder-Mobarry MHD code, Tsyganenko model, and GOES observations
journal, January 2006


Simulations of ring current proton pitch angle distributions
journal, January 1998


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


Statistical study of effect of solar wind dynamic pressure enhancements on dawn-to-dusk ring current asymmetry
journal, January 2006


REPAD: An empirical model of pitch angle distributions for energetic electrons in the Earth's outer radiation belt: pitch-angle model for outer-belt e-
journal, March 2014


Effects of interplanetary magnetic field z component and the solar wind dynamic pressure on the geosynchronous magnetic field
journal, April 1997


Nonlinear bounce resonances between magnetosonic waves and equatorially mirroring electrons
journal, August 2015


Response of magnetic fields at geosynchronous orbit and on the ground to the sudden changes of IMF B Z
journal, December 2013


Simulated magnetopause losses and Van Allen Probe flux dropouts
journal, February 2014


Numerical calculations of relativistic electron drift loss effect: RELATIVISTIC ELECTRON DRIFT LOSS
journal, September 2008


Relativistic electron drift shell splitting
journal, January 2002


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


Electron scattering by magnetosonic waves in the inner magnetosphere: ELECTRON SCATTERING BY MS WAVES
journal, January 2016


Magnetic coordinates
journal, August 1966


Response of the magnetic field in the geosynchronous orbit to solar wind dynamic pressure pulses: GEOSYNCHRONOUS RESPONSE TO SW PULSES
journal, December 2007


A quantitative assessment of empirical magnetic field models at geosynchronous orbit during magnetic storms: TEST MAGNETIC FIELD MODELS
journal, April 2008


Characteristics of pitch angle distributions of hundreds of keV electrons in the slot region and inner radiation belt
journal, December 2014


Works referencing / citing this record:

The Effects of Solar Wind Dynamic Pressure Changes on the Substorm Auroras and Energetic Electron Injections on 24 August 2005
journal, January 2018


Observations of Impulsive Electric Fields Induced by Interplanetary Shock
journal, August 2018


Effect of Low‐Harmonic Magnetosonic Waves on the Radiation Belt Electrons Inside the Plasmasphere
journal, May 2019