Comment on “Nucleation of Mesospheric Cloud Particles: Sensitivities and Limits” by L. Megner

摘要

In my article “Minimal impact on condensation nuclei properties on observable mesospheric ice properties” (Megner, 2011, https://doi.org/10.1016/j.jastp.2010.08.006) I show that the observable bulk quantities of Noctilucent clouds are much less sensitive to the concentration of condensation nuclei than what previously has been believed. These results were challenged by Wilms et al. (2016, https://doi.org/ 10.1002/2015JA021764), who studied the effect of nucleation rate on cloud properties and find a sensitivity. In this comment I argue that the differences between the studies are less than they first appear: Both studies show a very limited sensitivity to ice condensation nuclei, especially when there are more than roughly 100 condensation nuclei per cubic centimeter. Observations do indicate that under normal conditions, there are at least around 100 particles per cubic centimeter in the region of formation, and thus that we are in the insensitive regime.