Feature

Red Snow, Green Snow

It's truly spring when those last white drifts go technicolor

By Susan Milius

- More than 2 years ago

Microbiologist Brian Duval hates this part, so let’s just deal with the snickering up front. Yes, he studies yellow snow.

No, it’s not a murder scene. A bloom of the alga Chlamydomonas nivalis reddens the snow beside a hip-high evergreen in the Sierra Nevadas of California. Duval

It takes an expert to tell, but this yellow stain revealed by digging in the snow comes from a bloom of a Chloromonas alga in Yosemite National Park.