Fig. 1From: Evaluation of a method to derive ionospheric conductivities using two auroral emissions (428 and 630 nm) measured with a photometer at Tromsø (69.6°N)Intensity ratio of the emission intensity at 630.0 nm to that at 427.8 nm; a model calculation of the intensity ratio of the emission intensity at 630.0 nm to the emission intensity at 427.8 nm versus the average energy of incident electronsBack to article page