Pink night clouds

03/09/12, 9 pm, looking up

I was imagining being underwater and looking up at fish swimming above through the dark water. I try to paint clouds rather than astronomy if there are clouds. The pink clouds on Friday night were few and far between but I managed this little grouping of altocumulus.


Why are they pink? I don't know. It seems unlikely that they are reflecting the sodium-vapor street lights, but maybe. Maybe the color is changed by some difference in refraction at night. A quick search online did not provide any definitive answer.