Correlated electron and X ray measurements of quiet time electron precipitation: a comparative study of Bremsstrahlung production and transport in the atmosphere
Five cases of X ray observations from balloons coordinated with measurements of precipitating electrons were obtained during passes of the polar-orbiting satellite P78-1 near Siple, Antarctica (L--4.1), the launch point of the balloons. The observations, made during a geomagnetically quiet period in late December 1980 to early January 1981, showed small enhancements of the X ray fluxes (E>25 keV) and moderate trapped electron fluxes (E>68 keV) with pitch angle distributions extending into the edge of the loss cone sufficient to produce the approx. <0.5 dB of cosmic noise absorption recorded by the Siple 30-MHz riometer. Bremsstrahlung production and transport in the atmosphere were calculated using the measured electron fluxes, energy spectra, and pitch angle distributions for the source. The X ray fluxes and spectra calculated for the balloon altitudes were in good agreement with those measured from the balloons when the total energy deposition from electrons, E>10 keV, exceeded 2 x 10/sup -3/ erg/cm/sup 2/ s. The observed electron fluxes show that a significant continuous electron precipitation occurs at the western edge of the South Atlantic magnetic anomaly even at times of low geomagnetic activity.
- Research Organization:
- Lockheed Palo Alto Research Laboratory, Palo Alto, California
- OSTI ID:
- 7021892
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 91:A12
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
EARTH ATMOSPHERE
ELECTRON PRECIPITATION
ANGULAR DISTRIBUTION
BALLOONS
BREMSSTRAHLUNG
DATA ANALYSIS
ELECTRON DENSITY
ENERGY SPECTRA
GEOMAGNETIC FIELD
LOSS CONE
SATELLITES
X-RAY SPECTRA
AIRSHIPS
CHARGED-PARTICLE PRECIPITATION
DISTRIBUTION
ELECTROMAGNETIC RADIATION
MAGNETIC FIELDS
RADIATIONS
SPECTRA
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena