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Title: Dynamics and Structures of the Outer Radiation Belt

Abstract

From an analysis of electron measurements in the Explorer VI satellite (August 7-October 6, 1959) four timedependent parameters which characterize the outer electron belt were investigated. They are the equatorial electron intensity I/sub 0/ the equatorial range from the earth R/sub 0/ of the peak ibtensity, the electron-density distribution along a line of force through the intensity peak, and a measure of the change in electron spectrum with time. These parameters, along with measurements of magnetic field intensity, make it possible to study the origin of the changes in electron intensity and distribution which are known to occur in the outer belt. Magnetic storms occurred during the observation on Explorer VI. Within the sequence of changes in the outer belt induced by these geomagnetic storms, there are changes of the parameters which are accounted for only by invoking an irreversible energy gain or loss within the outer belt. The energy gain process appears to be through irreversible local acceleration of electrons. The energy loss process leads to a stable mirrorpoint distribution characteristic of the periods between geomagnetic storms. The time intervals within which each of these processes is operative are identified. Reversible processes are possibly the cause for other changes.more » The foregoing analysis rests upon the proof given that the outerbelt peak intensity coincides over a wide range of geomagnetic latitudes with magnetic field lines of force in the centered dipole approximation. Consequently, the measured electron- intensity maximum is used as a'tracer' of the geomagnetic field lines of force for analyzing changes in the outer belt with time. It is shown that even during geomagnetic storms the trace of the electron-intensity maximum followed a centered dipole line of force. This indicates that at all times the particle- energy density of the radiation belt is much less than the energy density of the magnetic field in the region. The electron fluxes, high-energy proton fluxes, and possible electron spectra are investigated. Two distinct peaks of electron intensity are identified to persist in the outer belt for about 2 months, and it is shown that these peak distributions undergo radial motion during geomagnetic disturbances. (auth)« less

Authors:
; ;
Publication Date:
Research Org.:
Univ. of Chicago
Sponsoring Org.:
USDOE
OSTI Identifier:
4839790
NSA Number:
NSA-15-031465
Resource Type:
Journal Article
Journal Name:
J. Geophys. Research
Additional Journal Information:
Journal Volume: Vol: 66; Other Information: Orig. Receipt Date: 31-DEC-61
Country of Publication:
Country unknown/Code not available
Language:
English
Subject:
PHYSICS; ACCELERATION; DIPOLES; DISTRIBUTION; EARTH; ELECTRONS; ENERGY; EXPLORER SATELLITES; LEVELS; LOSSES; MAGNETIC FIELDS; MAGNETIC STORMS; MOTION; RADIATION BELTS; SATELLITES; TURBULENCE; VARIATIONS

Citation Formats

Fan, C Y, Meyer, P, and Simpson, J A. Dynamics and Structures of the Outer Radiation Belt. Country unknown/Code not available: N. p., 1961. Web. doi:10.1029/JZ066i009p02607.
Fan, C Y, Meyer, P, & Simpson, J A. Dynamics and Structures of the Outer Radiation Belt. Country unknown/Code not available. https://doi.org/10.1029/JZ066i009p02607
Fan, C Y, Meyer, P, and Simpson, J A. Fri . "Dynamics and Structures of the Outer Radiation Belt". Country unknown/Code not available. https://doi.org/10.1029/JZ066i009p02607.
@article{osti_4839790,
title = {Dynamics and Structures of the Outer Radiation Belt},
author = {Fan, C Y and Meyer, P and Simpson, J A},
abstractNote = {From an analysis of electron measurements in the Explorer VI satellite (August 7-October 6, 1959) four timedependent parameters which characterize the outer electron belt were investigated. They are the equatorial electron intensity I/sub 0/ the equatorial range from the earth R/sub 0/ of the peak ibtensity, the electron-density distribution along a line of force through the intensity peak, and a measure of the change in electron spectrum with time. These parameters, along with measurements of magnetic field intensity, make it possible to study the origin of the changes in electron intensity and distribution which are known to occur in the outer belt. Magnetic storms occurred during the observation on Explorer VI. Within the sequence of changes in the outer belt induced by these geomagnetic storms, there are changes of the parameters which are accounted for only by invoking an irreversible energy gain or loss within the outer belt. The energy gain process appears to be through irreversible local acceleration of electrons. The energy loss process leads to a stable mirrorpoint distribution characteristic of the periods between geomagnetic storms. The time intervals within which each of these processes is operative are identified. Reversible processes are possibly the cause for other changes. The foregoing analysis rests upon the proof given that the outerbelt peak intensity coincides over a wide range of geomagnetic latitudes with magnetic field lines of force in the centered dipole approximation. Consequently, the measured electron- intensity maximum is used as a'tracer' of the geomagnetic field lines of force for analyzing changes in the outer belt with time. It is shown that even during geomagnetic storms the trace of the electron-intensity maximum followed a centered dipole line of force. This indicates that at all times the particle- energy density of the radiation belt is much less than the energy density of the magnetic field in the region. The electron fluxes, high-energy proton fluxes, and possible electron spectra are investigated. Two distinct peaks of electron intensity are identified to persist in the outer belt for about 2 months, and it is shown that these peak distributions undergo radial motion during geomagnetic disturbances. (auth)},
doi = {10.1029/JZ066i009p02607},
url = {https://www.osti.gov/biblio/4839790}, journal = {J. Geophys. Research},
number = ,
volume = Vol: 66,
place = {Country unknown/Code not available},
year = {1961},
month = {9}
}