Global Warming

‘Watermelon Snow’: Possibly The Major Cause Behind Alarming Glaciers Melting

In the last three years, glaciers in the Arctic region have been melting at an alarming rate. This increased melting in Arctic glaciers has baffled scientists all over the world. So, what could be the major reason that has caused dramatic shrinkage of the Arctic ice?

Pink snow was a high-latitude curiosity described by Arctic explorers such as Britain’s John Ross. Upon receiving word of the reddish snow, the London Times speculated in 1818 that the colour came from meteoric iron deposits. Biologists know now that the red hue is the result of a chemical reaction within the algae Chlamydomonas nivalis and other cold-loving species. These algae are normally green, but as they start to suck up ultraviolet rays, they turn red.

What may look like an Arctic accident involving gallons of pink lemonade is, in fact, reddish algae blooming in the snow. The unusual phenomenon is also found in high altitudes, and sometimes called watermelon snow or blood snow.

According to a new study, the algae cause Arctic melts, which are already happening at an unprecedented pace because of climate change,to worsen.

In their paper published Wednesday in the journal Nature Communications, the researchers examined 40 red-snow samples, representing 16 glaciers and snowfields from four Arctic countries: Greenland, Norway, Sweden and Iceland. The red algae darkens the snow, they found, causing it to melt faster than its white counterpart.

Specifically, the European scientists measured the red snow’s albedo, the proportion of light reflected from a surface. It is a property of colour: Dark objects, by definition, absorb a higher percentage of incoming light. Because light is energy, objects that take in more light become hotter. Conversely, lighter-coloured objects reflect more energy and stay cooler.

Exactly how large or small a role algae plays in melting glaciers is unclear, and the scientists plan to study it in more depth. But the geobiologists are concerned that the decrease in albedo may act like a positive feedback loop. As more algae bloom, more snow thaws — and, nourished by the unfrozen water, even more of the microorganisms are able to grow. And so on.