Winter in the Arctic Circle is an eerie prison term , with the Sun having long since droppedbeneath the horizon , not to give for several months . However , the blackness of the icy northern sky also cater a perfect backdrop for some of the most spectacular and otherworldly rude phenomena known to man .
Of these , the most famous is of row the northlern lights – oraurora borealis – although a lesser - known yet equally jaw - spend weather case has been fire up the skies above the Norwegian urban center of Tromsø over the retiring few days : polar stratoshperic clouds(PSCs ) .
As the name suggest , these are formed in thestratosphere , a layer of the Earth ’s atmosphere that sits above the troposphere , where normal cloud are formed . Because PSCs come at higher altitudes than these regular clouds , the air that beleaguer them is peculiarly cold , and typically reaches around -85 ° C ( -121 ° F ) .
Consequently , PSCs tend to be made up of tiny frozen particles , and are just high enough to receive some of the Sun ’s electron beam . When this spark hits these speck , it gets refracted , splitting up into the unbelievable raiment of colors experience in these images , which were taken by local photographerTruls Melbye Tiller .
However , there is a gyp in the tail of these beautiful clouds , since they are thought to contribute to the destruction of theozone bed . This is because they offer a surface for a figure ofharmful chemical reaction , leave in the changeover of benign chlorine compounds into dangerous gas such as Cl monoxide .
astonishingly , Tiller toldSpaceweather.comthat the pictures were snap at 10.30 am – a fact which merely adds to the impressiveness of these arresting yet alarmingly grave clouds .
All images in text show gelid stratospheric cloud in northern Norway , shoot by Truls Melbye Tiller .
