Rocket observation of energetic electrons in the low-altitude auroral ionosphere during the DELTA campaign

摘要: This paper reports on properties of energetic electrons observed by the Auroral Particle Detector (APD) board sounding rocket S-310-35, which was launched from And/0ya Rocket Range, Norway, at 0033:00 UT 13 December 2004 during DELTA campaign. The APD designed to measure energy spectra in range 3.5 65 keV every 10 ms using avalanche photodiodes. measurement done altitudes 90–140 km (apogee height flight), corresponded collisional interaction region precipitating with atmospheric constituents. overall profile electron precipitations consistent auroral images taken ground. downward fluxes almost always exceeded those upward electrons, and ratio increased also altitude. is reasonably understood terms effect collisions between An interesting feature existence non-thermal higher energies, regardless inside or outside arcs. In order predict incident top atmosphere, we have applied an analytic method Luhmann (1976) evaluate spectra. As a result, most are well expressed kappa distributions thermal few hundreds eV 5–8, while spectrum strong arc better fitted sum Maxwellian distribution lower side power law energies. To authors’ knowledge, this first direct reliable 10-keV ionosphere.