Antarctica unexpectedly appeared 'watermelon snow'

Warming weather stimulates a red-colored algae to thrive and change the color of the snow and ice.

Chlamydomonas nivalis algae causes part of the Antarctic ice sheet to turn red.(Photo: Ukraine Ministry of Science and Education).

Ukraine's Ministry of Science and Education posted on social media photos of snow melon , or snow , in Antarctica on February 24. Ukraine's National Center for Science says Chlamydomonas nivalis is the cause of this phenomenon.

Chlamydomonas nivalis is a green algae but contains red pigments to protect them from ultraviolet radiation. Unlike most freshwater algae, they grow in cold areas. Red absorbs sunlight, melting snow and providing more water for algae to grow. The phenomenon of watermelon snow also occurs in the Arctic, the Alps and some other mountains.

According to scientists, the unusually warm weather in Antarctica has accelerated this phenomenon. In early February, temperatures at the Esperanza research station in Antarctica reached a record high of 18.3 degrees Celsius.

Chlamydomonas nivalis "hibernates " during the cold months. But when spring comes, the sunshine, the melting water from the snow and abundant nutrients stimulate them to multiply.