The scientists used the device to record the albedo of snow, a measure of how much sunlight is reflected back. Red snow means a lower albedo, which means more sunlight is absorbed and the snow melts faster. Other factors also affect albedo, including dirt, dust, and ash from wildfires. Sand from the Gobi Desert can blow as far as the Pacific Northwest, while dust from the shrinking Great Salt Lake sometimes covers the Wasatch Mountains. The team also measured the pigment concentration of the snow with a second spectrometer to find out how much of the red spectrum, most likely from snow algae, was present.
A large horned sheep was monitored from a jagged cliff high above us as the team carried out the rest of their routine: measuring the water content of the snow, collecting bags of snow samples, and taking snow cores for reveals two layers of algal blooms, including a clear strip of rust a few inches from the surface.
Later that day, in the lab at the University of Montana’s Flathead Lake Biological Station, Elser and Almela Gomez will use samples to test which inputs help snow algae grow. They will melt the snow, mix them together and add nutrients like nitrogen and phosphorus. Then, after 5 to 10 days under the grow light in a cold incubator, they will measure the chlorophyll levels to see how well the algae is growing.
The two types of nutrients come from different places. Previous work suggested that phosphorus was found in rocks formed by glacial movements, while nitrogen was blown in from chemical fertilizers and fertilizers in agricultural areas. The researchers suspect that both nutrients encourage algae growth, but they are particularly interested in nitrogen. They believe algal blooms may be particularly common in the Intermountain Rockies due to wind patterns, and they hope to learn more about the dynamics involved.
The team’s work is part of a small but growing field of snow algae research. Scientists hope to find out what allows snow algae to thrive and where it is most likely to live. Live Snow Project, a citizen science initiative created by Western Washington University researchers, asked skiers, mountaineers, and hikers to help collect samples of pink snow. Scientists have also converged on an increase in algal blooms in the French Alps.
Understanding what influences snow algae growth is an important step in understanding changing water supplies. More algae could mean more melting, and knowing where algae can melt snow faster is especially important for the drought-prone West. Melting snow is good; it creates a more predictable downstream water supply for reservoirs and transfers cold water into streams on which fisheries and other aquatic life depend during the hot summer months. However, rapidly melting snow brings a host of other problems.
Elser compared the role of snow to ice in a cocktail. He said: “The ice is melting, but your drink stays good and cold until that last iceberg is gone. “Then it was like, ‘What happened? My drink is still warm.’” If the algal blooms melt the snow faster or melt all the snow quickly, streams can become warmer than usual and have less water when summer arrives. “It’s a pretty big deal,” said Scott Hotaling, a member of the snow algae research group and an assistant professor at Wyoming State University who studies mountain ecosystem change. “We’re talking about the whole West being in a state of drought, and if there’s another factor that’s causing the ice to melt sooner, that’s very important.”
