⟪⟪ Polar stratospheric clouds ⟫⟫
Polar stratospheric clouds (PSCs) type II are also known as nacreous clouds and occur at a height of about twenty km when the temperature drops well below -80 °C. The colors are the result of diffraction, caused by the tiny ice crystals which the clouds are made of. Type I PSCs are made of acids and form at slightly higher temperatures, and are not iridescent. Because of their height, PSCs still receive some sunlight well after sunset, which is the reason for their bright orange appearance in some of these photos. More information about these clouds.
(2011-02-06)
(2011-02-06)
(2011-02-06)
(2011-02-06)
(2011-02-06)
(2011-02-06)
(2011-02-06)
Taken with a really crappy camera, hence the quality of the photo (2016-02-01)
(2016-12-31)
(2016-12-31)
(2016-12-31)
(2016-12-31)
(2017-02-13)
(2017-02-13)
(2017-12-24)
(2017-12-24)
(2017-12-24)
The same clouds, a couple of hours later (2017-12-24)
(2023-01-28)
(2023-01-28)