"Cities most people wouldn't expect rely on this runoff," said Chris Derksen, a glaciologist and Research Scientist with Environment and Climate Change Canada. "Big cities like San Francisco and Los Angeles get water from snowmelt."

To improve snowmelt forecasting, NASA's Earth Science Technology Office (ESTO) is collaborating with researchers from the University of Massachusetts, Amherst, to advance SNOWWI - a dual-frequency synthetic aperture radar system designed to assess snow mass on a global scale. This technology, which could lead future missions focused on global snowpack measurements, addresses a gap in current snow data collection.

In a significant milestone for SNOWWI, the research team conducted the instrument's first test flights over Grand Mesa, Colorado, in January and March 2024. These tests provided valuable data on winter snowfields and demonstrated the radar's transition from lab-based hardware to a functional tool producing meaningful data. "I'd say the big development is that we've gone from pieces of hardware in a lab to something that makes meaningful data," said Paul Siqueira, professor of engineering at the University of Massachusetts, Amherst, and principal investigator for SNOWWI.

Short for Snow Water-equivalent Wide Swath Interferometer and Scatterometer, SNOWWI uses two Ku-band radar signals: a high-frequency signal that interacts with snow grains and a low-frequency signal that penetrates through the snowpack to the ground. The high-frequency signal offers a detailed view of the snowpack's structure, while the low-frequency signal provides depth information.

"Having two frequencies allows us to better separate the influence of the snow microstructure from the influence of the snow depth," said Derksen, who was part of the Grand Mesa campaign. "One frequency is good, two frequencies are better."

As these radar signals reflect off the snowpack, they lose energy, which SNOWWI measures to assess the snowpack's depth, density, and mass. Operating from an altitude of 2.5 miles (4 kilometers), SNOWWI can map about 40 square miles (100 square kilometers) of snow-covered terrain in just half an hour. Once in space, SNOWWI's reach would increase even further. Siqueira is currently working with Capella Space to develop a satellite-ready version of SNOWWI for future space missions.

Before SNOWWI can be deployed in orbit, additional testing is planned. The next field campaign will take place in Idaho's mountainous terrain, where Siqueira hopes to evaluate SNOWWI's performance in more complex landscapes, beyond the relatively flat terrain of Grand Mesa.

Derksen, who specializes in assessing snowpack water content in Canada, emphasized the instrument's potential. "Snowmelt is money. It has intrinsic economic value," he said. "If you want your salmon to run in mountain streams in the spring, you must have snowmelt. But unlike other natural resources, at this time, we really can't monitor it very well."

For more information on NASA's opportunities for collaboration on innovative Earth-observing instruments, refer to ESTO's Instrument Incubator Program catalog of open solicitations here.

Related Links
SNOWWI
It's A White Out at TerraDaily.com