A new classification of a cloud was introduced on the International Weather Day on 23 Mars according to a RUV report. It is now a fully valid and recognized new kind of cloud, the first one introduced since 1953. A new International Cloud Atlas was unveiled for the occasion – the first one since 1987. The International Weather Day or World Meteorological Day marks the anniversary of the World Meteorological Organization’s establishment on March 23, 1950.
Asperitas was first proposed as a type of cloud in 2009 by Gavin Pretor-Pinney of the Cloud Appreciation Society and its now officially recognized and has been added to the new International Cloud Atlas. According to the Cloud Atlas the Asperitas has “well-defined, wave-like structures in the underside of the cloud; more chaotic and with less horizontal organization than the variety undulates. Asperitas is characterized by localized waves in the cloud base, either smooth or dappled with smaller features, sometimes descending into sharp points, as if viewing a roughened sea surface from below. Varying levels of illumination and thickness of the cloud can lead to dramatic visual effects.