snow to look pink, thus the name watermelon snow . This pink snow was even mentioned in the early writings of the Greek philosopher Aristotle. In 2020, the “pink invader” caused problems for Italy’s massive Presena alpine glacier. The algae did not directly damage the glacier, but it did make the glacier’s surface darker. As a result, the glacier absorbed more sunlight, and its melting rapidly increased. Watermelon snow is also called blood snow , and it occurs during the summer in Antarctica. The ice around the Vernadsky Research Base located on Galindez Island was covered in blood snow in 2020. The red-pigmented algae species Chlamydomonas nivalis was responsible. These algae love freezing water and are dormant in the ice and snow during winter. When the snow melts in summer, the algae bloom and spread their red spores. The red color comes from pigmented carotenoids, the same pigments that are in carrots and pumpkins. For the algae, the pigments are protective, shielding them from ultraviolet light and lowering the risk of genetic mutations. Snowflake Shapes Scientists say that there are indeed no two snowflakes that are completely alike. Many factors determine the shape of a snowflake, and the air temperature around the forming snowflake is one. Long needlelike structures form around 28°F (-2°C), and in lower temperatures, below 23°F (-5°C), they form into very flat crystals that look like dinner plates. Temperature fluctuations occur as the snowflake falls, and these changes further shape the crystals. The snowflake first forms around a single particle—like a speck of dust or pollen—and all snowflakes have six arms, called a dendritic structure. Scientists have cataloged over thirty-five different variations of snowflakes: column, plane, rimed, irregular, and combinations of these. Snowflakes can grow as large as 15 inches when temperatures are much colder!


The New Weather: Amazing Weather Facts

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