Accession Number : ADA299616

Title :   A Study of Polar Cap Electron Precipitation Events to Determine Source Region Parameters.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Cahanin, Steven E.

PDF Url : ADA299616

Report Date : 10 SEP 1995

Pagination or Media Count : 216

Abstract : A thorough understanding of polar cap electron precipitation and the source region of these particles is essential for producing accurate models of the near earth space environment. Although this phenomenon received considerable attention during the 1980s, most researchers have now focused their attention on one specific form of polar cap electron precipitation, the sun aligned arc. By examining energy flux/time series plots from 976 passes of the Defense Meteorological Satellite Program (DMSP) F-8 SSJ/4 polar cap satellite from 1 November 1989 through 31 December 1989, enormous variety of structures was found. These structures, regardless of their respective energy flux, are the focus of this research and will be referred to as polar cap electron precipitation events. By selecting only those events that occurred under northward IMP conditions and at magnetic latitude greater than 800, the events were then sorted by the collecting energy channel and by different total energy flux categories. By assuming the source region particles have a Maxwellian distribution, proceed down open field fines, are accelerated by a potential drop, and obey Louville's Theorem, the source region parameters are described. In particular, the source region kT temperature (energy) is found to be generally invariant while the electron number density varies by an order of magnitude.

Descriptors :   *ELECTROSTATIC PRECIPITATION, *POLAR CAP ABSORPTION, MAGNETIC FIELDS, PARAMETERS, FLUX(RATE), ELECTRON DENSITY, THESES, METEOROLOGICAL SATELLITES, ELECTRON ENERGY, SOLAR RADIATION, MAXWELLS EQUATIONS, IONOSPHERIC MODELS, HIGH LATITUDES, DISTRIBUTION FUNCTIONS, LIOUVILLE EQUATION.

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE