Asperitas, also known as Undulatus asperatus, is a unique cloud formation characterized by wave-like structures in the underside of the cloud. Gavin Pretor-Pinney, the founder of the Cloud Appreciation Society, popularized it as a new cloud type in 2009. In March 2017, the International Cloud Atlas added Asperitas as a supplementary feature, making it the first cloud formation … [Read more...] about Asperitas Cloud: Definition, History of Observations, and Characteristics