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SNOWEX NASA Takes Snowpack Study to the Skies Words: Amelia Arvesen
For at least the last 100 years, people have collected manual observations on the ground to understand how much snow pack exists. While satellites help map snow cover and track changes, there are limitations. “We’re pretty good at measuring the area that the snowpack covers, but we’re not very good at measuring the amount of water stored in that snowpack,” Elder says. SnowEx, launched in 2017, is trying to close that gap in remote sensing knowledge. Snow-water equivalent, or SWE, informs flood and drought predictions as well as hydropower, reservoir, agriculture, and water resource decisions. It also informs outdoor recreation and ecological aspects, such as wildlife migration patterns and food access. But its measurement over a significant area requires more than one instrument. It’s inefficient and, in most cases, impossible to send hundreds of field workers into high altitudes and remote areas to keep collecting data. From January to March, a NASA aircraft flew over select locations in the West to measure snowpack while a team of field researchers like Dylan Craybeek dug dozens of holes in the snow below. “It takes close to an hour, and I’ll dig anywhere between four and eight pits on a field day,” Craybeek says. Spread across six sites in Idaho, Montana, Utah, and Colorado this winter, these researchers measured snow depth, density, temperature, 14
grain size, and liquid water content, among other data points. The corroboration of the data collected from the air with the data collected on the ground is part of a years-long NASA-funded program called SnowEx. One of the reasons they’re studying the massive swath of snowpack is because it’s changing, partly due to climate change, and the decrease in snow has an impact that extends far beyond the ski resorts. Scientists predict that, eventually, water isn’t going to flow freely as it does now. “The one thing we can’t live without is water,” says Kelly Elder, one of the research hydrologists for the U.S. Forest Service. “People think oil is valuable, but that’s because people in power have all the water they want to drink now. Many people already live without adequate clean water.”
The one thing we can’t live without is water.
