photo #6099096

China, it is considered lucky to spot colours in the clouds. Colourful clouds evoke the traditional decorative patterns known as xiangyun (‘auspicious clouds’), used to symbolise peace and happiness. Yating Yang, editor of the Chinese edition of the Cloud Appreciation Society’s book The Cloud Collector’s Handbook, must have enjoyed a run of good luck after she spotted these colourful Cirrocumulus lenticularis clouds above Lhasa, Tibet. The iridescent effect results from the cloud’s tiny, uniformly sized water droplets and ice crystals dispersing the sunlight, by a process called diffraction, into its constituent wavelengths that we see as bands of pastel colours. Different formations can produce this cloud iridescence as the sunlight shines through, but it’s rare to see colours as vivid as Yating’s. Auspicious, indeed.Cirrocumulus lenticularis clouds with iridescence spotted above Lhasa, Tibet by Yating Yang and submitted by Yanping Wang (Member 52,913).