Publication Date:
2019-06-28
Description:
Auroral emission features at high geomagnetic latitudes are identified and characterized using simultaneous optical and particle data from the ISIS-2 satellite. Polar cap arcs are identified from two-dimensional geomagnetic transforms of the optical data along with precipitating electron data for the time at which the satellite is on the field line intersecting the arc. No precipitating protons were detected for any of the arc crossings. The precipitations particle characteristics include: (1) an electron energy spectrum with a peak in the range 350-750 eV superposed on a soft spectrum like that observed in polar rain; (2) a normally isotropic pitch angle dependence, with the exception that field-aligned fluxes are observed in association with an inverted 'v' event; and (3) an energy flux range of approximately 0.8-3 erg/(sq cm s). A possible explanation of the observed precipitating particle characteristics is that parallel electric fields are accelerating polar rain type spectra at an altitude of several thousand km.
Keywords:
GEOPHYSICS
Type:
Planetary and Space Science; 31; Feb. 198
Format:
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