Significance of lunar impact on noctilucent clouds

In this study, we conduct a statistical analysis of the relationship between more than 40 years of variations in noctilucent clouds (NLCs) and lunar orbital motion. Monthly (29.53 days) and semi-monthly (14.77 days) components related to changes in the lunar age generate modulation in the probability of NLC occurrence of about 20% and 10%, respectively, with a statistical significance of 99%. Changes in the distance between the Moon and Earth influence the frequency of the occurrence of NLCs: the probability of observing these clouds is greater when the Moon is close to perigee and apogee. A weather factor is also significant for ground-based observations made from a single point.