The Amazing Science Behind Polar Colours

4 August 2022
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Antarctica, Arctic

It’s not just the sheer magnitude of Antarctica and the Arctic Circle that commands a traveller’s attention. The planet’s polar regions are nature’s canvas for a colour scheme not seen anywhere else on earth! 

Inside a Blue Ice Cave in the heart of a glacier near Jokulsarlon, Vatnajokull National Park, Iceland

Glaciology Optics

Glacial ice is a very different beast from the cubes floating around in a summer cocktail.

The eye-popping blues, turquoises and aquamarines owe their super cool looks to the ice density of glaciers which absorb every other colour of the spectrum, except blue. Crystalline structures compacted over aeons channel blue light in a different way to what human eyes normally interpret ice properties.

When glacial ice initially freezes, it fills with air bubbles. As that ice is buried and compressed underneath younger ice on top, the older ice starts to take on a blue tinge. As the ice grows denser, the bubbles eventually reduce to tiny levels.

Without the scattering effect of these air bubbles, light can penetrate ice more deeply. For our eyes, ancient glacial ice acts as a filter, absorbing red, orange and yellow light and reflecting blue light, creating swathes of bewitching blue hues.

Ice Formation in Antarctica just beyond the Gerlache Strait

Air Max White

Conversely, snow is white because it’s loaded with light scattering air bubbles, and snow reflects the full spectrum of white light. A simple home-based example of this is found in the light-coloured foam on a newly opened carbonated drink. This light phenomenon occurs in all forms of water and is responsible for making the ocean appear blue, while the crest of a crashing wave is white.

Waves crashing on Jokulsarlon Diamond Ice glacial beach in Iceland

Hair of the Bear

The science of colour variation also applies to the iconic ‘white’ polar bear, as somewhat surprisingly, they aren’t actually white! The hollow hairs of their fur coats are clear and contain no pigmentation. Their colour is determined by the environment’s lighting and climate. In the Arctic, they reflect the sunlight and appear white, but can also turn yellow or grey depending on their surroundings.

Polar bear and cub

Neon Nights

One of the greatest displays of colour anywhere on earth can be found when Aurora Borealis lights up skies in both hemispheres near the poles. These swaying neon ribbons in the darkness result from a very specific light phenomenon that occurs when disturbances from the sun drag on Earth’s magnetic field.

When electrons from the sun reach Earth’s thin upper atmosphere, the collision with nitrogen and oxygen molecules excites their state. Eventually, when this combination calms and releases light, the aurora is born into the heavens!

A round of applause then for science.

Colourful northern lights in Iceland

Ready to start planning your incredible Arctic or Antarctica expedition cruise?

Simply complete our enquiry form to get in touch, or call our Polar Specialists on 0203 196 1000.

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