An Update on the Asperatus Cloud

Members and visitors might remember that a couple of years ago we proposed that a new classification of cloud should be added to the official classification system. Photographs of this cloud formation had been sent in by Society members over the years, and we’d never known quite how to classify them since we felt that they didn’t easily fit into the existing cloud terms.

The cloud looks a little like the surface of the sea on a choppy day, which is why we proposed that it should be called asperatus from the Latin verb ‘aspero’, meaning to make rough. The term was used by Roman poets to describe the sea as it was roughened by the cold north wind.