Every winter in the countries where temperature falls below zero, snow drops out. Children play snowballs, adults go on the rimed crust, listening as it crackles underfoot. Snow of habitual white color is not to anybody surprising. However sometimes on the earth also red snow can lay down.
Water-melon snow
Red snow most often can be found in subpolar areas or it is high in mountains. From far away it is not visible, the snow massif can have only hardly noticeable crimson shade. However it is worth pressing somehow snow – to walk on it, to pass by car or on skis as the unusual shade becomes obvious.
Scientists found out what happens to habitual white color of snow. monocelled alga of a sort of a hlamidomonad – a hlamidomonad snow (Chlamydomonas nivalis) was responsible for so unusual metamorphoses. Unlike most of representatives of its sort, this look prefers to live in cold and, at first sight, adverse conditions.
At a temperature above +4os the hlamidomonada snow cannot exist and massively perishes.
Besides a green pigment of a chlorophyll, the hlamidomonada has also astaxanthin – a carotinoid of red color. It also gives characteristic brown or pink coloring. In the most severe frosts the alga is at rest, however air temperature should rise slightly as the hlamidomonada snow begins to breed. Just as it is possible to observe water blossoming in the summer, in cold season in mountains or polar regions it is possible to see how snow blossoms. And not only color changes. Red snow gets also very notable water-melon smell. Hlamidomonada snow is the most often meeting representative of wildlife who paints snow, however over 350 species of seaweed can be engaged in similar metamorphoses. Those who can paint snow yellow, blue, green, brown or black color occur among them.
Rafidonema snow (Rhaphidonema nivale) paints snow in green, and Ancylonema Nordenskioeldii antsilonema – in brown color.
Red snow hands of the person
Sometimes change color of snow not only an alga. The person is also capable to cause the similar phenomenon. The interesting case occurred in the Nikolaev region in Ukraine where inhabitants very were surprised once, having gone outside and having seen that instead of habitual white there is red snow. It turned out that the reason is in activity of alumina refinery where there was an emission of red slime. Because of strong cold weather the waste also dropped out on the earth together with precipitation and presented to locals an opportunity to admire the fantastic landscapes reminding photos from Mars.