May 2 2013

From The Space Library

RELEASE: 13-131 - NASA OPENS NEW ERA IN MEASURING WESTERN U.S. SNOWPACK --WASHINGTON -- A new NASA airborne mission has created the first maps of the entire snowpack of two major mountain watersheds in California and Colorado, producing the most accurate measurements to date of how much water they hold. The data from NASA's Airborne Snow Observatory mission will be used to estimate how much water will flow out of the basins when the snow melts. The data-gathering technology could improve water management for 1.5 billion people worldwide who rely on snowmelt for their water supply. The Airborne Snow Observatory is on the cutting edge of snow remote-sensing science, said Jared Entin, a program manager in the Earth Science Division at NASA Headquarters in Washington. "Decision makers like power companies and water managers now are receiving these data, which may have immediate economic benefits." The mission is a collaboration between NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., and the California Department of Water Resources in Sacramento. A Twin Otter aircraft carrying NASA's Airborne Snow Observatory began a three-year demonstration mission in April that includes weekly flights over the Tuolumne River Basin in California's Sierra Nevada and monthly flights over Colorado's Uncompahgre River Basin. The flights will run through the end of the snowmelt season, which typically occurs in July. The Tuolumne watershed and its Hetch Hetchy Reservoir are the primary water supply for San Francisco. The Uncompahgre watershed is part of the Upper Colorado River Basin that supplies water to much of the western United States. The mission's principal investigator, Tom Painter of JPL, said the mission fills a critical need in an increasingly thirsty world, initially focusing on the western United States, where snowmelt provides more than 75 percent of the total freshwater supply. Changes in and pressure on snowmelt-dependent water systems are motivating water managers, governments and others to improve understanding of snow and its melt, Painter said. "The western United States and other regions face significant water resource challenges because of population growth and faster melt and runoff of snowpacks caused by climate change. NASA's Airborne Snow Observatory combines the best available technologies to provide precise, timely information for assessing snowpack volume and melt." The observatory's two instruments measure two properties most critical to understanding snowmelt runoff and timing. Those two properties have been mostly unmeasured until now. A scanning lidar system from the Canadian firm Optech Inc. of Vaughan, Ontario, measures snow depth to determine the first property, snow water equivalent with lasers. Snow water equivalent represents the amount of water in the snow on a mountain. It is used to calculate the amount of water that will run off. An imaging spectrometer built by another Canadian concern, ITRES of Calgary, Alberta, measures the second property, snow albedo. Snow albedo represents the amount of sunlight reflected and absorbed by snow. Snow albedo controls the speed of snowmelt and timing of its runoff. By combining these data, scientists can tell how changes in the absorption of sunlight cause snowmelt rates to increase. The Airborne Snow Observatory flies at an altitude of 17,500 feet - 22,000 feet (5,334 to 6,705 meters) to produce frequent maps that scientists can use to monitor changes over time. It can calculate snow depth to within about 4 inches (10 centimeters) and snow water equivalent to within 5 percent. Data are processed on the ground and made available to participating water managers within 24 hours. Before now, Sierra Nevada snow water equivalent estimates have been extrapolated from monthly manual ground snow surveys conducted from January through April. These survey sites are sparsely located, primarily in lower to middle elevations that melt free of snow each spring, while snow remains at higher elevations. Water managers use these survey data to forecast annual water supplies. The information affects decisions by local water districts, agricultural interests and others. The sparse sampling can lead to large errors. In contrast, the NASA observatory can map all the snow throughout the entire snowmelt season. The Airborne Snow Observatory is providing California water managers the first near-real-time, comprehensive determination of basin-wide snow water equivalent, said Frank Gehrke, mission co-investigator and chief of the California Cooperative Snow Surveys Program for the California Department of Water Resources. "Integrated into models, these data will enhance the state's reservoir operations, permitting more efficient flood control, water supply management and hydroelectric power generation." Gehrke said the state will continue to conduct manual surveys while it incorporates the Airborne Snow Observatory data. "The snow surveys are relatively inexpensive, help validate observatory data and provide snow density measurements that are key to reducing errors in estimating snow water equivalent," he said. Painter plans to expand the airborne mapping program to the entire Upper Colorado River Basin and Sierra Nevada. "We believe this is the future of water management in the western United States," he said.

RELEASE: 13-132 - NASA ASTROPHYSICIST ELECTED TO NATIONAL ACADEMY OF SCIENCES --WASHINGTON -- NASA astrophysicist Chryssa Kouveliotou, a senior scientist at NASA's Marshall Space Flight Center in Huntsville, Ala., has been selected for membership in the National Academy of Sciences, in recognition of her distinguished and continuing achievements in original scientific research. Kouveliotou, a longtime leading researcher in NASA's space science mission, conducts extensive research on a host of astronomical phenomena including black holes, neutron stars and gamma-ray bursts. She is one of 84 new members and 21 foreign associates from 14 countries recently announced as members. I salute the National Academy of Sciences for their recognition of the groundbreaking scientific contributions that Dr. Kouveliotou has made in the field of high energy astrophysics, said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington. "Her work in expanding our knowledge of the nature of cosmic gamma-ray bursts, and her broad efforts in the service of science are exemplary of the creativity, collaboration and innovation that are hallmarks of a great scientist. I extend my heartfelt congratulations to her, and am confident that she will continue to do great science and serve the nation as a member of the academy." Kouveliotou, who joined NASA in 2004, has been the principal investigator on numerous research projects in the United States and Europe. Currently, she is a co-investigator on the Gamma-ray Burst Monitor, an instrument flying aboard the Fermi Gamma-ray Space Telescope; an associated scientist on Swift, a multi-wavelength observatory dedicated to the study of gamma-ray burst science; and a member of the NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) science team, researching topics that investigate the most powerful explosions in the universe. Throughout her career, she has worked on a succession of vital NASA research missions, including the International Sun Earth Explorer-3, the Solar Maximum Mission and the Burst and Transient Source Experiment, which flew on NASA's Compton Gamma-Ray Observatory. Her numerous contributions to the fields of astronomy and astrophysics have expanded scientific understanding of fleeting, transient phenomena in the Milky Way galaxy and throughout the universe. Besides determining the unique properties of the highly energetic emissions from gamma-ray bursts -- the brightest and most powerful cosmic events ever documented -- Kouveliotou was part of the team which first revealed the extragalactic nature of these sources. She and her team made the first confirmed detection of ultra-dense neutron stars called magnetars, which are the cinders of stars left over after a supernova. A native of Athens, Greece, Kouveliotou has received numerous awards for her work. In 2012 alone, she earned the Dannie Heineman Prize for Astrophysics and the NASA Exceptional Service Medal, and was named one of Time Magazine's 25 most influential people in space.