Accession Number : ADP006273

Title :   X-Ray Imagery of Energetic Electron Inputs to the Atmosphere at High Latitudes,

Corporate Author : LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA PALO ALTO RESEARCH LAB

Personal Author(s) : Imhof, W. L. ; Datlowe, D. W. ; Gaines, E. E. ; Mobilia, J. ; Vondrak, R. R.

Report Date : 03 MAY 1990

Pagination or Media Count : 10

Abstract : The precipitation of electrons > 4 keV into the atmosphere occurs at locations spanning a wide range of latitudes and longitudes. The regions where these electrons precipitate have been mapped with a bremsstrahlung x-ray spectrometer in the SEEP payload on the S81-1 spacecraft. Spike-like x-ray emission regions are observed from precipitation originating in the radiation belts. A spike is most often present near the outer edge of the belt, frequently in the form of an arc at a constant invariant latitude. Poleward of the radiation belt boundary, strong arcs are observed as well as weaker patches and widespread events. The arcs are most often singular, but pairs of adjacent arcs are also observed. Detailed energy spectrum and intensity versus latitude profiles of these events have also been measured with electron spectrometers on the satellite. The energy inputs to the atmosphere from electron precipitation >4 keV are generally concentrated in very localized regions in contrast to the more widespread inputs from lower energy electrons. This may produce significant gradients in ionization in the upper atmosphere and thereby affect radio wave propagation. The energy deposition profiles at these restricted positions are presented and compared with the profiles due to cosmic rays which occur at all latitudes and longitudes.

Descriptors :   *IONOSPHERIC DISTURBANCES, ELECTRON DENSITY, HIGH LATITUDES, PRECIPITATION, BREMSSTRAHLUNG, RADIATION BELTS, PROFILES, RADIO WAVES.

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE