Global Change in the Mesosphere and the Question of the Appearance of Noctilucent Clouds Before 1885

Abstract

It is known that noctilucent clouds were first observed in 1885, two years after the great Krakatoa eruption in the Sunda Straits. The pre-eminent question whether noctilucent clouds appeared before 1885 is here studied in detail. Using various literature sources and observational records for the 19th century by several observers it can be shown that before 1885 noctilucent clouds were never described in the literature. The so-called phenomenon “bright nights” or “Leuchtstreifen” was well-known in the 19th century, but no observer described any structures which can be identified as noctilucent clouds. This result makes it clear that the noctilucent clouds seen in 1885 were the first such observations made. A possible increase in frequency of occurrence can be estimated from the year of discovery up to the present day.