There has been no shortage of coverage on the news concerning California’s drought issues. Much of the water supplied to California comes from mountain snowmelt. The measurement of that snow is critical to making informed decisions about water conservation. A special pilot project called Airborne Snow Observatory (ASO) is responsible for taking those measurements with ground based crews as well as a specially modified King Air A90.
“Snow really anchors the water resource, which itself anchors the civilization, the infrastructure, the ability to have the industry we have, the agriculture that we have, the huge populations that we have,” noted Tom Painter, founder of the ASO.
The specially designed Beechcraft King Air A90 uses lasers that fire off 800,000 times per second from the bottom of the aircraft while flying missions over the Sierra Nevada mountains. A LIDAR system utilizes an imaging spectrometer to gather data about snow depth, water content and whiteness, which determines the speed of the melt.
The Sierra Nevada supplies between one-third and two-third’s of the state’s freshwater. Measuring it allows scientists and water managers to know precisely how much water exists in the snowpack over large areas. After each mission, the information is made available within 24 hours. This gives a quick and accurate prediction of how much water the mountains will feed rivers and reservoirs during spring.
California has been recording snowpack for over a century. Historically, the technique used was just sinking large, hollow metal cylinders in the snow. However, this measurement system did not measure water at elevations higher than 11,350 feet. Now, using the King Air, the Airborne Snow Observatory can take measurements of higher altitudes from overhead. This allows for a much broader and accurate picture of how much snow exists, and by proxy, how much water.
The Airborne Snow Observatory is looking to expand the program significantly. The ultimate goal is to have three or more planes in operation, surveying the entirety of the Sierra Nevada. Currently, the project is only able to survey a handful of basins. If successful, the project could be used to measure snowpack at sites around the globe. This will become vital with drought conditions in the world become increasingly more frequent.