When parts of clouds are thin and have similar size droplets, diffraction can make them shine with colours like a corona. In fact, the colours are essentially corona fragments. The effect is called cloud iridescence or irisation, terms derived from Iris the Greek personification of the rainbow.
The usually delicate colours can be in almost random patches or bands at cloud edges. They are only organised into coronal rings when the droplet size is uniform right across the cloud. The bands and colours change or come and go as the cloud evolves. They occur most often in altocumulus, cirrocumulus and especially in lenticular clouds. Uniform size droplets and iridescence is seen mostly when parts of clouds are forming or finally dispersing.
Sometimes iridescence can be seen far from the sun but is most frequent near to it. As for coronas, search safely by hiding the sun behind a building and, even better, also viewing the reflection of the sky in water.
Very much rarer iridescence is that of nacreous or mother-of-pearl clouds. They can glow very brightly and are far higher than ordinary tropospheric clouds.
Wow!!! It's amazing!! I've never seen such phenomenum in Costa Rica, maybe the light angle has to be very specific or snow and cold temperature has something to do with it. Where were they taken?
Wow!!! It's amazing!! I've never seen such phenomenum in Costa Rica, maybe the light angle has to be very specific or snow and cold temperature has something to do with it. Where were they taken?
It was in iceland this morning.
We have bright light maby for 3 hours now here in the north..
Not the best time for outside photografhy :(
