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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Automated system tracks snowpack in remote areas

Michelle Boss

Precipitation reports are important for many reasons. There are issues to deal with on both sides of the spectrum when it comes to amounts. Too much, and flooding, mud slides, and even ruined harvests are a possibility. Too little, and again agriculture, our use of water for recreation, and our basic need for fresh drinking water are affected.

It is relatively easy to keep track of the liquid precipitation, rainfall. There are many different types of rain gauges available, from the simple tin can, to the more advanced automated “tipping bucket” rain gauges.

It is a little more difficult to measure frozen precipitation, such as hail or snow. Both need to be melted down, and then measured, to get the accurate liquid equivalent.

When it comes to snowfall amounts, the best way to get an accurate measurement is to have someone physically go out and stick a ruler in it. In mountainous or remote areas, however, that is not always practical, but keeping tabs on mountain snowpack is important. The amount of snow falling in the mountains throughout the winter, and how fast it melts off during the spring, have implications throughout the whole year.

For about the last three decades, an automated system called SNOTEL (which stands for snowpack telemetry), has been keeping track of such mountain snow data. One of the interesting ways these automated systems keep track of snow depth, is by use of what’s called a pressure sensing snow “pillow.” This pillow, about the size of a water bed, contains an anti-freeze-like solution. The pressure on the solution, and its subsequent displacement, are affected by the weight of snow on top of it.

There are 730 SNOTEL sites located in 13 states, including Alaska. Observations are taken at remote locations, nearly half a dozen of which are at elevations above 6,000 feet. The system, operated by the Natural Resources Conservation Service, collects the data on snowfall, which is used for producing water supply forecasts, supporting climate studies, air and water quality investigations, and water resource management.

In addition to the interesting technology that allows snow measurements to be taken automatically in these remote locations, is the technology used to transmit that data. In what is called “meteor burst communications,” radio signals are sent upward 50 to 75 miles above the earth to an ever present band of ionized meteorites. The signal is reflected off those meteorites back to earth and received at Portland’s National Water and Climate Center.

Michelle Boss can be reached at weatherboss@comcast.net.