Diffusion of 155 to 430 keV protons in the Earth's radiation belt

2001 ◽  
Vol 106 (A4) ◽  
pp. 5957-5966 ◽  
Author(s):  
M. Walt ◽  
H. D. Voss ◽  
S. J. Lev-Tov ◽  
J. Mobilia ◽  
J.-M. Jahn
Keyword(s):  
Radiation Belt ◽  
Earth’S Radiation Belt

scholarly journals POLAR spacecraft observations of helium ion angular anisotropy in the Earth's radiation belts

1999 ◽  
Vol 17 (6) ◽  
pp. 723-733 ◽  
Author(s):  
W. N. Spjeldvik ◽  
T. A. Fritz ◽  
J. Chen ◽  
R. B. Sheldon
Keyword(s):  
Local Time ◽  
Pitch Angle ◽  
Radiation Belt ◽  
Radiation Belts ◽  
Magnetic Local Time ◽  
Angle Distribution ◽  
Pitch Angle Distribution ◽  
Helium Ion ◽  
Earth’S Radiation Belt ◽  
Earth's Radiation Belts

Abstract. New observations of energetic helium ion fluxes in the Earth's radiation belts have been obtained with the CAMMICE/HIT instrument on the ISTP/GGS POLAR spacecraft during the extended geomagnetically low activity period April through October 1996. POLAR executes a high inclination trajectory that crosses over both polar cap regions and passes over the geomagnetic equator in the heart of the radiation belts. The latter attribute makes possible direct observations of nearly the full equatorial helium ion pitch angle distributions in the heart of the Earth's radiation belt region. Additionally, the spacecraft often re-encounters the same geomagnetic flux tube at a substantially off-equatorial location within a few tens of minutes prior to or after the equatorial crossing. This makes both the equatorial pitch angle distribution and an expanded view of the local off-equatorial pitch angle distribution observable. The orbit of POLAR also permitted observations to be made in conjugate magnetic local time sectors over the course of the same day, and this afforded direct comparison of observations on diametrically opposite locations in the Earth's radiation belt region at closely spaced times. Results from four helium ion data channels covering ion kinetic energies from 520 to 8200 KeV show that the distributions display trapped particle characteristics with angular flux peaks for equatorially mirroring particles as one might reasonably expect. However, the helium ion pitch angle distributions generally flattened out for equatorial pitch angles below about 45°. Significant and systematic helium ion anisotropy difference at conjugate magnetic local time were also observed, and we report quiet time azimuthal variations of the anisotropy index.Key words. Magnetospheric physics (energetic particles · trapped; magnetospheric configuration and dynamics; plasmasphere)

scholarly journals Seasonal dependence of the Earth's radiation belt – new insights

2021 ◽  
Vol 39 (1) ◽  
pp. 181-187
Author(s):  
Rajkumar Hajra
Keyword(s):  
Radiation Belt ◽  
Space Environment ◽  
Flux Variation ◽  
Annual Peak ◽  
Radiation Belt Electrons ◽  
Potential Impact ◽  
Two Peaks ◽  
First Time ◽  
Earth’S Radiation Belt

Abstract. Long-term variations in the relativistic (∼MeV) electrons in the Earth's radiation belt are explored to study seasonal features of the electrons. An L-shell dependence of the seasonal variations in the electrons is reported for the first time. A clear ∼6 month periodicity, representing one/two peaks per year, is identified for 1.5–6.0 MeV electron fluxes in the L shells between ∼3.0 and ∼5.0. The relativistic electron flux variation is strongest during solar cycle descending to minimum phases, with weaker/no variations during solar maximum. If two peaks per year occur, they are largely asymmetric in amplitude. The peaks essentially do not have an equinoctial dependence. Sometimes the peaks are shifted to solstices, and sometimes only one annual peak is observed. No such seasonal features are prominent for L<3.0 and L>5.0. The results imply varying solar/interplanetary drivers of the radiation belt electrons at different L shells. This has a potential impact on the modeling of the space environment. Plausible solar drivers are discussed.

scholarly journals Operational Nowcasting of Electron Flux Levels in the Outer Zone of Earth's Radiation Belt

Space Weather ◽  
2018 ◽  
Vol 16 (5) ◽  
pp. 501-518 ◽  
Author(s):  
Tim Coleman ◽  
James P. McCollough ◽  
Shawn Young ◽  
E. Joshua Rigler
Keyword(s):  
Radiation Belt ◽  
Electron Flux ◽  
Outer Zone ◽  
Earth’S Radiation Belt

Complementarity of Measurements and Models in Reproducing Earth’s Radiation Belt Dynamics

2007 ◽  
pp. 219-229
Author(s):  
S. Bourdarie ◽  
V. Maget ◽  
R. Friedel ◽  
D. Boscher ◽  
A. Sicard ◽  
...  
Keyword(s):  
Radiation Belt ◽  
Earth’S Radiation Belt

Electrons With Energy Exceeding 10 MeV in the Earth's Radiation Belt

2013 ◽  
pp. 129-133 ◽  
Author(s):  
A. M. Galper ◽  
V. V. Dmitrenko ◽  
V. M. Gratchev ◽  
Yu. V. Efremova ◽  
V. G. Kirillov-Ugryumov ◽  
...  
Keyword(s):  
Radiation Belt ◽  
Earth’S Radiation Belt
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