NON-COLLISIONAL IONIZATION AND TEMPERATURE LAYERS IN THE AURORAL E F-1 LAYER - EISCAT OBSERVATIONS/

EISCAT observations of thin layers of enhanced ionization and elevated electron temperature during auroral precipitations, similar to the ph enomenon of tile 'Enhanced Aurora', are presented and described. Being well narrower than those predicted by the conventional collisional ap proach, the layers are likely caused by plasma turbulence generated by precipitating elections and field-aligned currents in the altitude ra nge 110-170 km. The results are in a qualitative agreement with the mo del of the plasma turbulence layer which takes the influence of collis ions upon the beam-plasma interaction into account.