John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
You could become the official face of “asperitas,” the first novel cloud type identified since 1951.
It looks like an upside-down mountain range. Or rolling, vaporous surf. Or a misty carpet you want to beat the lumps from. It’s “asperitas,” the first new cloud type identified since 1951.
Sky-watchers have reported the oddly distorted clouds for years; note this apparition of “liquid silver” over Iowa in 2006. But now, thanks to years of effort from the most lovable lobbying group ever, the Cloud Appreciation Society, the formations likely will be getting official recognition.
A formation made up of well-defined, wavelike structures in the underside of the cloud, more chaotic and with less horizontal organization than undulatus. It is characterised 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 cloud can lead to dramatic visual effects.
If all goes well, the WMO will include asperitas in its revised 2016 International Cloud Atlas—a “standardized reference document for operational observation systems, which underpin weather forecasts and longer-term climate predictions.” But there’s unfinished business: To make it into that esteemed guide, somebody needs to snap a photo of asperitas in all its weird glory.
The “WMO have asked us to help provide a photograph of the new cloud type for the book,” the cloud society writes. “This is why we have launched a competition to find the best photograph of asperitas to appear in the International Cloud Atlas as the reference image against which all asperitas spottings will be judged.” Head here to find out how you can participate in the cloud-off, whose winner will be announced in September.
Meanwhile, these are a few recent examples from the society and elsewhere of what to look for: