Glaciating Clouds at Sunset

November 09, 2015


Photographer: Mark Ritter
Summary Authors: Mark Ritter; Jim Foster
The dramatic swooping clouds shown above are most likely glaciated altocumulus clouds illuminated by the setting Sun. They take on a rather fuzzy appearance probably because ice crystals have fallen into them from higher aloft, perhaps from dissipating cirrus clouds. Mid-level clouds, including altocumulus, are typically more sharply defined since they're composed of minute water droplets that readily evaporate. Note that at ground level the Sun has already dipped below the horizon. Photo observed from Murrieta, California, on October 28, 2015.