What is Watermelon Snow?

Snow is white or whiteish, right?

Wrong!

There is yellow, orange, grey, green, black, blue and even red snow! Some of the colours come from dust and dirt, while others come from algae.

Watermelon snow is also known as blood snow, pink or red snow. You find this snow in mountains and polar regions. The colour comes from algae – freshwater green Chlamydomonas nivalis. During the spring and summer months, the algae produce a red carotenoid pigment. This pigment protects the algae from the Sun’s rays. almost like a natural sunscreen against the sun’s ultraviolet rays. This causes the snow to absorb the sun’s heat and reduces the snow’s ability to reflect heat so snow containing this algae melts faster. The reflective surface is decreased when the algae is present and this could speed up the melting rates of glaciers.

By studying how the snow algae’s UV protection mechanism works we could develop sustainable and biocompatible alternatives to chemical sunscreens. We could design sensors that detect and monitor UV radiation levels in different environments. Also, we could design sensors that change colours in response to UV exposure.

Can you think of anything else inspired by watermelon snow?

What different coloured types of snow have you seen? Why was the snow this particular colour? Can you design something inspired by this snow?