The way the polar stratospheric clouds 2017-18 winter season begins is out-of-this-world

1

The stratosphere above the Arctic Circle is getting cold … very cold. That’s one way – the only way for space weather scientists – to explain these colorful clouds – polar stratospheric clouds (PSCs) – which require temperatures around -85ºC to form and appeared over Norway and Sweden on Dec. 20th:

polar stratospheric cloud norway december 2017, polar stratospheric cloud, polar stratospheric cloud season 2017/2018, polar stratospheric cloud december 2017 pictures
Polar stratospheric clouds over Norway on December 20, 2017. By Fredrik Broms / www.northernlightsphotography.no

This absolutely stunning display of stratospheric clouds appeared high above the ordinary gray rainclouds. It’s very seldom to see PSCs with such vivid colours as today.

polar stratospheric cloud norway december 2017, polar stratospheric cloud, polar stratospheric cloud season 2017/2018, polar stratospheric cloud december 2017 pictures
Polar stratospheric clouds over Norway on December 20, 2017. By Fredrik Broms / www.northernlightsphotography.no

As their name implies, these surreal clouds form in the extremely dry stratosphere, high above Earth’s surface. In this second layer of Earth’s atmosphere – starting between 33,000–43,000 ft; 6.2–8.1 mi) and ending at 50 km (160,000 ft; 31 mi) almost no clouds of any type can form.

polar stratospheric cloud norway december 2017, polar stratospheric cloud, polar stratospheric cloud season 2017/2018, polar stratospheric cloud december 2017 pictures
Polar stratospheric clouds over Norway on December 20, 2017. By Fredrik Broms / www.northernlightsphotography.no
polar stratospheric cloud norway december 2017, polar stratospheric cloud, polar stratospheric cloud season 2017/2018, polar stratospheric cloud december 2017 pictures
Polar stratospheric clouds over Norway on December 20, 2017. By Fredrik Broms / www.northernlightsphotography.no

However, when the the air up there becomes extremely cold, rare water molecules coalesce and form ice crystals. High-altitude sunlight refracting on the ice creates these mind-blowing iridescent colors.

polar stratospheric cloud norway december 2017, polar stratospheric cloud, polar stratospheric cloud season 2017/2018, polar stratospheric cloud december 2017 pictures
Nacreous clouds over Sweden on December 20, 2017. By Oliver Wright
polar stratospheric cloud norway december 2017, polar stratospheric cloud, polar stratospheric cloud season 2017/2018, polar stratospheric cloud december 2017 pictures
Nacreous clouds over Sweden on December 20, 2017. By Oliver Wright

Keep your eyes to the sky, the 2017-18 winter season for polar stratospheric clouds is just starting.

Follow us: Facebook and Twitter

1 Comment

  1. Is that sunlight through the drops of frozen water that clouds can have.
    Or is it … Haarp radiation. Those oval circles in those clouds and those colors …

Leave a reply

Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.