'Watermelon' Snow Phenomenon: Wonderfully Beautiful And Quite Dangerous At The Same Time

Date December 13, 2018

Winter, especially when it's snowy, is a fascinating time of beauty that gives us not only wonderful landscapes, but also some natural phenomena which are sometimes rationally inexplicable. For example, we are all sure that snowflakes are white. However, that's not completely true, as each snowflake is made of transparent crystals of various shapes and sizes. Still, it's an accepted standard to think of snow as white, except for when it is arbitrarily colored various shades and intensities of pink and emits a pleasant aroma somewhat reminding one of a fresh, juicy watermelon. It is due to this fragrance that this phenomenon got its original and even somewhat poetic name.

For many years, 'watermelon' snow has simply been accepted as one of the mysteries of nature. It was only in the 19th century that the Scottish botanist Robert Brown determined the reason for the changes in pigmentation. He was the first to discover an accumulation of Chlamydomonas nivalis algae in the red spots of the snow. They are cold-resistant plants that are able to survive at low temperatures.

It is worth noting that their existence is not explained by climatic or seasonal cycles, as they can thrive in any place suitable for life and growth. On cold days, they completely dive into anabiosis, ceasing all activity. Moreover, in periods of rest we wouldn't even guess that they existed so close to us.

Another interesting fact worth noting is that all the specimens of Chlamydomonas nivalis have a green color, typical of most of plants. Thus, what's the secret of the pink pigmentation?

The snow becomes pink during a thaw, when the sun rays contribute to its melting. During this period, the veil of snow loses its homogeneity and ability to reflect life. When certain circumstances coincide, there is a favorable time for algae blossoming as they acquire the characteristic red shade, which is also a protective reaction to the rise in temperature. By changing the color of the surface, they contribute to a quicker melting of the snow by reducing the light-reflecting characteristic features. This can be compared to the choice of summer clothes colors - light fabrics are much more comfortable than dark ones, as they absorb less heat.

Although 'watermelon' snow is very unusual, it poses a certain danger not only to residents of the regions where it's already a common phenomenon, but also to the world's population. Firstly, the content of Chlamydomonas nivalis is somewhat toxic and contact with it, for both humans and domestic pets, is not recommended. Secondly, this species of organisms actively develop on the surfaces of glaciers, contributing to their melting and as a result, provoking changes to the climate of our planet.

Undoubtedly, scientists try to control the growth of the algae population and continue to study their activity. Pink snow is unusually beautiful, as you can see by taking a look at the bright photos. Nevertheless, remember that you should admire this phenomenon at a distance, keeping the nature of its development in mind.