Nasa Aims To Measure Vital Snow Data From Satellites

DENVER (AP) — 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. 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. Four sensors will measure snow density: three other types of radar, plus a passive microwave instrument, which detects how much of the Earth's natural microwave radiation the snow is blocking. Aircraft will take the instruments on multiple passes over two areas in western Colorado, Grand Mesa and Senator Beck Basin. Water utilities, farmers, public safety agencies and wildland firefighters track the updates closely to help predict how much drinking and irrigation water will be available in the spring and whether they will face floods or fire-inducing droughts. SNOTEL collects data from individual points, but the "holy grail of mountain hydrology" is a way to estimate the distribution of snow water equivalent across broad mountain landscapes, said Molotch, who is also director of the University of Colorado's Center for Water, Earth Science and Technology. Government agencies that forecast the spring runoff say satellite data on snow water equivalent would help them, although they base their predictions on multiple sources of information, including rain, temperature and current river flows.