Accession Number : ADA114311

Title :   Modeling of High-Latitude Currents in a Substorm,

Corporate Author : RICE UNIV HOUSTON TX

Personal Author(s) : Karty,J L ; Chen,C -K ; Wolf,R A ; Harel,M ; Spiro,R W

PDF Url : ADA114311

Report Date : 11 Dec 1981

Pagination or Media Count : 33

Abstract : A quantitative model is developed for computing currents and electric fields in the area covered by the poleward set of field-aligned currents (region-1 Birkeland currents). The high-latitude band considered carries most of the westward electrojet and lies just poleward of the region treated in the Rice University computer simulation (which covers the inner magnetosphere and corresponding ionosphere); the present high-latitude-current model supplements the inner-magnetosphere simulations to make them nearly global. Birkeland current and aurorally enhanced conductivity are assumed to be uniformly distributed across the band. The area poleward of the band is taken to be an insulator, while boundary conditions at the lao-latitude edge of the band are derived from the results of the lower-latitude computer simulations of the substorm event that occurred on September 19, 1976. The time-dependent conductivity model used is based on electron fluxes and mean energies measured from the Air Force S3-2 satellite. Ionospheric electric fields and currents are calculated; ionospheric neutral winds are neglected. Model prediction of the locations of the electric-field reversal agree well with typical 0G0-6 stellite observations. Joule heating of the upper atmosphere, as inferred from calculation of currents and electric fields in the high-latitude region considered here, was found to be about 2 x 10 to the 11th power watts during the substorm period, somewhat less than the value estimated for the lower-latitude region (region-2 and below).

Descriptors :   *MAGNETIC STORMS, *HIGH LATITUDES, IONOSPHERIC DISTURBANCES, MAGNETOSPHERE, ELECTRIC FIELDS, ELECTRIC CURRENT, ELECTROJETS, COMPUTERIZED SIMULATION, COUPLING(INTERACTION), SOLAR WIND

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE