Luminous Night Clouds over Norway in 1933 and 1934

Abstract

As reported in a letter to NATURE¹ large masses of noctilucent clouds were seen over southern Norway in the night of June 30-July 1, 1934. From three of my aurora stations I got a series of simultaneous photographs of these clouds. The plates have now been measured, and the results will soon appear in Astrophysica norvegica. The following points from this paper may be of interest: Seven pairs of plates gave the following 41 heights in kilometres: 82, 83, 82.5, 84, 84, 82.5, 82.5, 82, 83.5, 82, 82, 85, 82.5, 81, 82, 84, 81, 80.5, 81, 82, 81.5, 81, 81.5, 82.5, 82.5, 82, 82, 82.5, 83, 82, 78, 82, 82, 83.5, 82, 82, 81, 83.5, 82.5, 83, 81. The mean, 82.2 km., agrees very well with the mean value 82.08 km. found by Jesse from observations in the years 1889–91. It also agrees with my own measurements from 1932, which gave 81.4 km.