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Local-time survey of plasma at low altitudes over the auroral zones.Local-time survey of the low-energy proton and electron intensities precipitated into the earth's atmosphere over the auroral zones during periods of magnetic quiescence. This survey was constructed by selecting a typical individual satellite crossing of this region in each of eight local-time sectors from a large library of similar observations with the polar-orbiting satellite Injun 5. The trapping boundary for more-energetic electron intensities, E greater than 45 keV, was found to be a 'natural coordinate' for delineating the boundary between the two major types of lower-energy, 50 less than or equal to E less than or equal to 15,000 eV, electron precipitation commonly observed over the auroral zones at low altitudes. Poleward of this trapping boundary inverted 'V' electron precipitation bands are observed in all local-time sectors. These inverted 'V' electron bands in the evening and midnight sectors are typically more energetic and have greater latitudinal widths than their counterparts in the noon and morning sectors. In general, the main contributors to the electron energy influx into the earth's atmosphere over the auroral zones are the electron inverted 'V' precipitation poleward of the trapping boundary in late evening, the plasma-sheet electron intensities equatorward of this boundary in early morning, and both of these precipitation events near local midnight.
Document ID
19720055073
Document Type
Reprint (Version printed in journal)
Authors
Frank, L. A.
Ackerson, K. L. (Iowa, University Iowa City, Iowa, United States)
Date Acquired
August 6, 2013
Publication Date
August 1, 1972
Publication Information
Publication: Journal of Geophysical Research
Volume: 77
Subject Category
GEOPHYSICS
Report/Patent Number
AD-749423
Funding Number(s)
CONTRACT_GRANT: N00014-68-A-0196-0003
CONTRACT_GRANT: NGL-16-001-002
CONTRACT_GRANT: NAS1-8141
CONTRACT_GRANT: NAS5-10625
CONTRACT_GRANT: NAS1-2973
Distribution Limits
Public
Copyright
Other