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Particles and fields: Significant achievements, 2
Author(s) -
Schardt Alois W.,
Opp Albert G.
Publication year - 1969
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1029/rg007i004p00799
Subject(s) - physics , cosmic ray , magnetosphere , solar wind , solar energetic particles , earth's magnetic field , van allen radiation belt , population , heliosphere , geophysics , astrophysics , computational physics , magnetic field , astronomy , plasma , coronal mass ejection , nuclear physics , demography , quantum mechanics , sociology
Satellite observations of energetic particles and magnetic fields during the last years have contributed greatly toward understanding our environment. Studies of nonadiabatic processes that occur in the radiation belts have led to a qualitative understanding of several source and loss mechanisms responsible for the observed particle population. A plasma instability leading to spontaneous emission of VLF and ELF wave has been found that limits the maximum flux of protons and electrons that can be trapped in the geomagnetic field. It has been shown that diffusion of particles into the magnetosphere is accompanied by a gain in particle energy; this process probably accounts for most of the lower‐energy particles found in the Van Allen belts. A comprehensive description of the geomagnetic field has been completed. Corrections for the current systems at the magnetospheric boundary and in the magnetotail have been applied in a comprehensive model. Secular changes in the main field have been interpreted in terms of core motion in the earth. Initial measurements have been performed of the galactic cosmic‐ray gradient in the solar system between Venus and Mars. Theories for explaining this gradient in terms of observable properties of the solar wind are being perfected. The relative abundance and energy spectra of hydrogen and helium isotopes in cosmic radiation have been explained in terms of interstellar matter traversed by the cosmic‐ray particles.