Accession Number : AD0696070

Title :   A SURVEY OF LOW-ENERGY (E GREATER THAN OR APPROXIMATELY EQUAL TO 5 keV) ELECTRON ENERGY FLUXES OVER THE NORTHERN AURORAL REGIONS WITH SATELLITE INJUN 4,

Corporate Author : IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Craven,John D.

Report Date : JUL 1969

Pagination or Media Count : 66

Abstract : Observations of the energy fluxes of greater than or approximately equal to 5 keV electrons at low altitudes (approximately 525-2500 km) over the northern auroral regions have been made by the nearly-polar orbiting Injun 4 satellite, from February, 1965, through July, 1966, during a period of minimum solar activity. Results of the first detailed survey of the percentages of occurrence of the energy fluxes of greater than or approximately equal to 5 keV electrons (with pitch angles approximately 40 deg plus or minus 15 deg) in the outer radiation/auroral zone, as a function of magnetic local time and invariant latitude, are graphically displayed for various energy flux thresholds. The greatest occurrences of these energy fluxes were observed in the night-dawn-morning hours of local time, at latitudes from approximately 65 deg to approximately 70 deg, with median energy fluxes as great as 0.1 ergs square cm-sec-sr to the minus 1. The spatial distributions of these contours are compared with those for the occurrences of optical auroras. Limited simultaneous observations of these energy fluxes at pitch angles of approximately 40 deg and approximately 90 deg have shown that the ratios of these energy fluxes are typically greater than 0.1, with a condition of isotropy occurring for energy fluxes greater than or approximately equal to 1 erg square cm-sec-sr to the minus 1. (Author)

Descriptors :   (*SCIENTIFIC SATELLITES, POLAR ORBIT TRAJECTORIES), (*AURORAE, ELECTRON IRRADIATION), LOW ORBIT TRAJECTORIES, DATA TRANSMISSION SYSTEMS, SCINTILLATION COUNTERS, SOLAR RADIATION, SAMPLING, PERIODIC VARIATIONS

Subject Categories : Atmospheric Physics
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE