Nacreous cloud: 'Mother-of-pearl' seen in some areas of Scotland
- Published
Nacreous cloud forms in very cold conditions over polar regions around 12 to 19 miles high.
They are one of the highest clouds in our atmosphere and usually have shimmering colours.
They are so rare in the UK because of the very cold conditions needed for them to form.
Nacreous clouds are mostly seen a couple of hours either side of sunset or sunrise.
The clouds are formed in air that is around minus 80 C.
Sunlight reflects off tiny ice crystals in the cloud giving it its pearly colours - that is why they are also called mother-of-pearl.
- Published19 July 2018
- Published22 January 2023
