Table 2

List of all observations shown in this work along with parameters and geophysical conditions. This selection represents a subset of our database, pertinent with our understanding and conclusions. “Alm” stands for “Almucantar” which is a circle of constant elevation in the sky. In this case, we simply perform a full rotation at a constant elevation. f10.7 and Ap values are taken respectively from the Space Weather Canada (https://www.spaceweather.gc.ca/solarflux/sx-en.php) and the International Service of Geomagnetic Indices websites (http://isgi.unistra.fr/data_plot.php). The last column (Atmospheric conditions) is based on our eye observations, on the all-sky camera archives available here: http://tid.uio.no/plasma/allsky_camera, on the local weather bulletins and when available on the analysis of the local lidar in Ny Alesund.