Cloud Condensation Nuclei Measurements Within Clouds

Abstract

Measurements of the spectra of cloud condensation nuclei (CCN) within and near the boundaries of clouds are presented. Some of the in-cloud measurements excluded the nuclei within cloud droplets; these are interstitial CCN while other measurements included all nuclei inside the cloud (total CCN). The difference between these spectra can be used to determine which nuclei are involved in cloud droplets. The vast majority of the data indicate that droplets are more likely to be grown on nuclei with lower critical supersaturations as predicted by classical theory. This technique is introduced as a possible tool for investigating the effects of mixing on the evolution of the droplet spectra.