Thumbnail
Access Restriction
Open

Author Imhof, W. L. ♦ Reagan, J. B. ♦ Gaines, E. E.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ RADIATION BELTS ♦ ELECTRON PRECIPITATION ♦ DAILY VARIATIONS ♦ ENERGY SPECTRA ♦ INCLINATION ♦ KEV RANGE 100-1000 ♦ MAGNETOSPHERE ♦ TRAPPED ELECTRONS ♦ CHARGED-PARTICLE PRECIPITATION ♦ EARTH ATMOSPHERE ♦ ELECTRONS ♦ ELEMENTARY PARTICLES ♦ ENERGY RANGE ♦ FERMIONS ♦ KEV RANGE ♦ LEPTONS ♦ SPECTRA ♦ VARIATIONS ♦ Atmospheric Physics- Magnetospheric Phenomena- (-1987)
Abstract Energetic electron (> or approx. =0.16 MeV) data taken from November 1972 to April 1973 from over 1000 passes of a low-altitude (approx.750 km) noon-midnight polar-orbiting satellite across the L=1.75 field line in both the northern and southern hemispheres have been analyzed for evidence of the longitude and local time distributions in electron precipitation on that field line. The precipitation processes were observed to be weak, at least near local noon and midnight, as evidenced from the negligible fluxes observed at all pitch angles when the conjugate point is below sea level and from the absence of any direct observation of electrons at L=1.75 in the bounce loss cone at all longitudes. By observing quasi-trapped fluxes with a spectrometer having a large geometric factor, a high sensitivity was achieved for detecting electron precipitation and measuring the energy spectra with fine resolution. The data have been analyzed and found to show that prounounced precipitation events near local noon and midnight were a rare occurrence between approx.60 /sup 0/E and approx.100 /sup 0/E. In the approx.100 /sup 0/E to approx.180 /sup 0/E longitude region, significant fluxes of quasi-trapped electrons were often observed with a very pronounced noon-midnight asymmetry. The quasi-trapped fluxes observed locally in the region were often large near midnight but seldom significant near noontime. From the electron data it was found that within a given local time and longitude interval the fluxes were widely variable, indicating that the precipitation mechanism(s) were not steady in time. Also, during the time period of observation, the average intensities of the quasi-trapped electrons were higher at times of high negative Dst.
Educational Use Research
Learning Resource Type Article
Publisher Date 1980-01-01
Publisher Department Space Sciences Laboratory, Lockheed Palo Alto Research Laboratory, Palo Alto, California 94304
Publisher Place United States
Journal J. Geophys. Res.
Volume Number 85
Issue Number A1
Organization Space Sciences Laboratory, Lockheed Palo Alto Research Laboratory, Palo Alto, California 94304


Open content in new tab

   Open content in new tab