temperature are achingly insensate in the stratosphere over the Arctic , which can only think one thing : it ’s sodding conditions for psychedelic skies filled with rainbow - emblazon clouds .
character II polar stratospheric clouds ( PSCs ) are known as one of the most beautiful cloud types in Earth ’s repertoire , seem above the Arctic and Antarctic as piano glowing whisps with a colorful iridescent shimmer .
Also known asnacreous cloudsor “ mother - of - pearl clouds ” , they take shape during winter and other spring in the opposite stratosphere , the secondly - lowest level of Earth ’s atmosphere , which is normally too teetotal for clouds . However , when temperatures are low enough – lower than -78 ° C ( -108.4 ° F ) – the stratosphere can produce PSCs despite the parched condition .
A photograph of polar stratospheric clouds over Kongsberg in Norway, taken by an iPhone 5.Image credit: Stein Arne Jensen viaFlickr(Public Domain)
According to current information fromNASA ’s Goddard Earth Observing System , stratospheric temperature in the upper reaches of the Northern Hemisphere are already stale enough for Type II PSCs to mold , and they are forecasted to drop even further by the ending of January .
Nacreous cloud populate around 20 to 30 kilometers ( 68,500 to 100,000 feet ) above Earth ’s open when water vaporisation and other chemicals in the atmosphere freeze down into tiny airborne sparkler crystals .
They typically appear in the diametric stratosphere when the Sun dip just below the horizon . Due to their tiny ice crystals scattering illumination in unique ways , these rarefied cloud have a striking , luminous luminescence when run into with sunlight . Their high-pitched altitude , plus the curve of the Earth ’s surface , also help to create the ideal illumination .
It is possible to occasionally see iridescent cloudsas far as in the south as the UK . However , they are most common in polar neighborhood during the winter when temperature are sufficiently chilly .
As beautiful as they may be , PSCs can have aless - than - suitable effecton Earth ’s surroundings by playing akey theatrical role in the formation of the ozone holein the Antarctic and Arctic . The clouds contain chemicals , like nitric acid and sulfuric dose , as well as a airfoil that facilitates chemical reactions , produce chlorine stem that deplete ozone .
The safe word is that the Arctic hasnever had a pregnant ozone holeand the Antarctic ’s ozone level is thehealthiest it ’s been in decades .
So , if you ’re favourable enough to catch pot of a pearlescent swarm , finger free to enjoy them without too much guilt .
