Fig. 1
From: Auroral molecular-emission effects on the atomic oxygen line at 777.4 nm
a Height profiles of the EISCAT-measured electron density at 18:31:30 UT (blue) and 18:33:30 UT (orange) on March 2, 2017. Measurement uncertainty of ± 1σ is marked by a horizontal bar in each color. b An image of the Tromsø all-sky camera, which was taken at 18:33:50 UT. The direction of the EISCAT radar and spectrograph measurements is marked by a yellow circle. Five faint lines from the northern edge represent contaminations of a sodium lidar. c Spectrum measured at 18:33:29 UT on March 2, 2017, at wavelength of 750–800 nm. A vertical dashed line is marked at 777.4 nm