The Arctic Circle is finest identified for its Northern Lights.
However this emerald show was not too long ago changed by spectacular iridescent rainbows.
Uncommon ‘rainbow clouds’ painted the skies over the Arctic Circle in Finland, Iceland and Norway on the finish of January.
The phenomenon, attributable to excessive freezing temperatures within the stratosphere, was captured by Icelandic novice photographer Jónína Guðrún Óskarsdóttir.
What are rainbow clouds?
Whereas auroras happen when photo voltaic wind collides with atoms within the Earth's ambiance, rainbow-coloured ‘polar stratospheric clouds’ (PSCs) are attributable to tiny atmospheric ice crystals.
So-called ‘rainbow clouds’ are a results of cloud iridescence attributable to small water droplets or ice crystals diffracting the solar’s mild.
The impact can typically be witnessed in small areas of low-level clouds. However the show is much extra dramatic when it occurs larger up, within the stratosphere.
PSCs type when water vapour enters the stratosphere and when temperatures are chilly sufficient for the vapour to condense there.
Since this layer of the ambiance may be very dry, ice crystals solely type when temperatures are under -81C - a uncommon incidence within the Arctic. PSCs happen larger up than common clouds, at altitudes of roughly 19 to 24 km.
In the course of the winter - or polar evening - there may be little to no radiation from the solar at excessive latitudes, inflicting important temperature drops. Below these situations, these ‘rainbow clouds’ can develop.
This phenomenon is comparatively uncommon as a result of it depends on a mixture of skinny clouds, chilly stratospheric temperatures, and plenty of water droplets or ice crystals of comparable sizes.
What impact do rainbow clouds have on the local weather?
Lovely as they're, rainbow clouds are unhealthy information for the local weather.
The chemical reactions that they encourage break down the ozone layer, which shields Earth from the solar’s dangerous UV rays.
Tiny ice crystals spark reactions between ozone and the chemical parts in chlorofluorocarbons (CFCs), that are launched into the ambiance by aerosols and fridges.
The ozone gap above the South Pole - the place PSCs are extra widespread there than within the Arctic attributable to decrease stratospheric temperatures - is attributable to these reactions.