A team of scientists at NASA's Jet Propulsion Laboratory is tracking California’s snowpack levels aboard a flying laboratory.
It’s called the Airborne Snow Observatory—a Beachcraft King Air turboprop plane with two key instruments on board measuring how much snow is on the ground through a hole in the belly of the aircraft.
Snowpack supplies about 70 percent of California’s annual precipitation, according to NASA, making it crucial to the water supply of a state that's experiencing a four-year drought.
“It’s unbelievably extreme compared to anything we have on record,” says Frank Gehrke, chief of California cooperative snow surveys for the California Department of Water Resources. “Where we would normally have 5, 6, 10 feet of snow, we’re seeing bare ground.”
“Water managers in these mountains always need to know how much snow pack there is, how quickly it's coming out, how quickly it’s going to come out, and how much total there is going to be,” says Tom Painter, the principal investigator and lead scientist for the program. “We can let them know exactly how much water there is.”
Painter and his team cycle through a rotation, flying three to four times a week over different basins in California and Colorado. They measure the snow depth using a scanning Lidar—a high-frequency laser that scans the ground 800,000 times a second. By tracking how quickly each pulse bounces back to the plane, they can tell the depth of the snow below.
They also use an imaging spectrometer, which measures sunlight in 100 different colors and tells the scientists how much sunlight is being reflected by the snow. From those data they can calculate how much water there will be when the snowpack melts. They then transfer that data to various water managers throughout the state.
“The various water managers that we are working with closely watch this information, they use it in their models, they use it in their decision-making with respect to allocation of water, and then knowing what the likely scenario is going to be over the next month as the last little bits of snow melt away,” Painter says.
The Airborne Snow Observatory program is a partnership between NASA’s Jet Propulsion Laboratory and the California Department of Water Resources. Next steps include expanding coverage throughout the Western U.S. into Colorado, Wyoming, Utah, and New Mexico and ultimately expanding the program internationally.
“To know that we are taking care of the most critical resource for this part of the world and, as we expand the program to other parts of the world, that we'll be taking care of the water resources for all those people, a billion and a half people worldwide, it's a good feeling to be able to bring the technology for that purpose,” Painter says.