Lasers in the sky: hi-tech missions track record snowpack loss in US west

High above the jagged peaks of California’s Sierra Nevada, the view from the cockpit is breathtaking. At first glance, the mountains appear draped in a pristine white blanket. But as the flight crew gears up for a high-stakes mission, the sensors onboard this specialized aircraft prove that looks can be deceiving. “This is a distinct dry year,” says Tom Painter, CEO of Airborne Snow Observatories. Painter, who developed this technology at Nasa, isn’t relying on a visual inspection. His plane uses Lidar, or rapid pulses of laser light, to calculate snow depth with surgical precision. “The Lidar sprays out about 800,000 pulses per second,” he explains. The result is a 3D map of snow depth accurate to within 3cm. The technology also helps determine how much water is stored in the snowpack. In the US west, where mountain ranges act as “frozen reservoirs”, state water managers rely on this data as a survival guide. It helps them plan for exactly how much water will eventually reach the faucets of millions of people and the critical farm fields that feed the nation. This year, the data is sounding an alarm. A record- breaking ’spigot shut off ’ The national drought picture is increasingly grim. According to the latest US Drought Monitor, more than 60% of the lower 48 states are now gripped by drought. It’s the most widespread spring dry spell since the monitor began in 2000. …