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AP
DENVER
Instrument-laden aircraft are surveying the Colorado high country this month as scientists search for better ways to measure how much water is locked up in the world's mountain snows water that sustains a substantial share of the global population.
A NASA-led experiment called SnowEx is using five aircraft to test 10 sensors that might one day be used to monitor snow from satellites. The goal: Find the ideal combination to overcome multiple obstacles, including how to analyse snow hidden beneath forest canopies.
"It would be, I would say, a monumental leap in our ability to forecast water supply if we had this kind of information," said Noah Molotch, a member of the science team for the experiment.
One-sixth of the world's population gets most of its fresh water from snow that melts and runs into waterways, said Ed Kim, a NASA researcher and lead scientist for SnowEx."Right there, it's hugely important for people."
Snow has other consequences for society as well, including floods, droughts and even political stability when water is scarce, Kim said.
The key to predicting how much water will pour out of mountain snows each spring is a measurement called snow water equivalent. The global average is 30 percent of snow depth, Kim said ” 10 inches of snow melts down to 3 inches of water. But a single mountain snowbank contains multiple layers with different snow water equivalents, making measurement difficult. The layers were dropped by successive storms with different moisture contents, and then lingered under different weather conditions before the next storm covered them.
A further complication: At times during the winter, some snow melts, so water will flow through the interior of the snowbank, distorting or absorbing signals from remote sensors.
