Women take a selfie next to a police officer as they take part in New Year's Eve celebrations in the Bund, in Shanghai, China December 31, 2016. (Photo by Aly Song/Reuters)

A black-winged stilt patrols a reservoir in Jezreel Valley in Israel early April 2023. Their eggs are a golden colour mottled with brown. (Photo by Itamar Procaccia/Solent News)

Sofia Evangelia Malkogeorgou and Evangelia Platanioti of Greece perform in the duet technical routine of the artistic swimming event during the Paris 2024 Olympic Games at the Aquatics Centre in Saint-Denis, north of Paris, on August 9, 2024. (Photo by Gonzalo Fuentes/Reuters)

Riders of the Peloton approach a cobbled section near the Arenberg forrest at the 117th Paris-Roubaix cycle race in Wallers, France on April 12, 2019. (Photo by Christophe Petit-Tesson/EPA)

“We've reached 40km.” – Participants run at the 40km mark of the 2025 Chosun Ilbo Chuncheon Marathon, held in Chuncheon, Gangwon Province, South Korea on the afternoon of the October 26, 2025. (Photo by Park Seong-won)

A handout picture provided by Global newsroom of Czech Martin Sonka (C) leading Nigel Lamb (top) of Great Britain and Yoshihide Muroya of Japan (down) along the Mount Fuji prior the third stage of the Red Bull Air Race World Championship in Chiba, Japan on June 1, 2016. (Photo by Predrag Vockovic/EPA/Global Newsroom)

In this photo taken late Thursday, May 7, 2015, a prison guard, left, and seated inmates cast shadows on a wall while waiting for the beginning of a rock concert by Romanian band Pro Musica, inside the Popa Sapca jail in Timisoara, western Romania. (Photo by Adi Piclisan/AP Photo)

Undulatus asperatus (or alternately, asperatus) is a cloud formation, proposed in 2009 as a separate cloud classification by the founder of the Cloud Appreciation Society. If successful it will be the first cloud formation added since cirrus intortus in 1951 to the International Cloud Atlas of the World Meteorological Organization. The name translates approximately as “roughened or agitated waves”.