Watermelon snow

Blood Snow is reddish colored, wet crud, which is found exclusively in the high mountains and polar regions during the summer months.

It is caused by a mass development of unicellular, pink to red-colored algae ( snow algae ), which are attributed to Kryoflora. It is, inter alia, to representatives of the genera Chlamydomonas and Chloromonas, which are assigned to the green algae. The coloration is caused by secondary carotenoids, especially by astaxanthin. An outdated but still common name for this pigment is Haematochrom. The algae protect themselves with the help of this carotenoid in front of the occurring particularly at extreme altitudes and in polar regions strong light and UV radiation. Chlamydomonas nivalis is a known type of blood snow -producing algae, but must be viewed as a collective species for the different types of algae that can be found on snow today.

Analogous to the rain of blood ( the Sahel wind) it can also be worn by the winds, red dust from deserts come to blood snow, the snowflakes take the sand in the fall and have as a precipitate a (yellowish / brownish ) red color.