COORDINATED EISCAT DMSP MEASUREMENTS OF ELECTRON-DENSITY AND ENERGETIC ELECTRON-PRECIPITATION/

A campaign was recently undertaken to obtain simultaneous radar and sa tellite measurements that would provide insight into the temporal and spatial morphology of the energetic particle precipitation. It include d coordinated field-aligned measurements of the altitudinal profile of the E region electron density from the European Incoherent Scatter (E ISCAT) radar, and measurements of the energetic particle precipitation from the SAMPEX and DMSP F10 and F12 satellites. The Strickland auror al electron transport code, with the recent addition of auroral proton transport, was employed to produce density profiles from the energeti c particle precipitation measurements by the SSJ/4 sensors on the DMSP F10 and F12 spacecraft for comparison with the EISCAT measurements. W e found good agreement between the EISCAT measurements and the model r esults for three of the four conjunctions including a very close conju nction (< 12 km) when the integral ion energy flux was greater than th e integral electron energy flux by a factor of 3 to 4. All of the conj unctions for which the results of the comparison were good occurred wi thin a stable diffuse aurora. Conductivity calculations using the mode l results varied less than 15% from calculations using the radar measu rements. The comparison was good even when the separation between the satellite and the radar was greater than 200 km. The fourth conjunctio n, for which the agreement was poor, occurred within the discrete auro ra during a very active period when the ionospheric conditions were dy namic both spatially and temporally.