NASA’S New Studies Of Earth’s Seas, Skies and Soils
[04-Jan-2006] They're carbonated, salty, and alternately wet and dry. Exotic champagnes? No, they're NASA's three Earth System Science Pathfinder small-satellite program missions: Orbiting Carbon Observatory, Aquarius and Hydros.
NASA has awarded all three of these fine "wines" gold medals of sorts by authorizing them to proceed with mission formulation. Each mission performs a first-of-a-kind exploratory measurement that will help answer fundamental questions about how our planet works and how it may change in the future. The Orbiting Carbon Observatory will enhance our understanding of Earth's carbon cycle and climate. Aquarius will examine the way oceans affect and respond to climate change. Hydros will study how water, energy and carbon are exchanged between land and Earth's atmosphere.
"These three innovative missions have demonstrated they are ready to use state-of-the-art remote sensing technology to observe and help us understand the cycles of water, energy and carbon through Earth's system. These are essential ingredients for sustaining life on Earth, and NASA is using the power of space technology to understand them," said Dr. Ghassem Asrar, NASA's associate administrator for Earth Science. "NASA plans to negotiate contract awards for these low-cost missions that address key scientific questions regarding how Earth's atmosphere, oceans and land work together to shape our weather, climate and environment," he said.
The Orbiting Carbon Observatory's two-year mission is targeted for launch in August 2007. It will provide the first global, space-based measurements of atmospheric carbon dioxide. The measurements will have the precision to identify and monitor human and natural processes responsible for absorbing and emitting this important greenhouse gas, a fundamental building block for food, fiber and life on Earth.
Precise ground-based measurements, collected since the 1970s, indicate only about half of the carbon dioxide emitted into the atmosphere by fossil fuel combustion has remained there. The land and oceans have apparently absorbed the rest. However, ground-based measurements are not adequate to determine how or where this absorption is occurring. These uncertainties compromise our ability to predict future atmospheric carbon dioxide concentrations or their effect on the climate system.
Dr. David Crisp of NASA's Jet Propulsion Laboratory, Pasadena, California, is principal investigator for the mission, which includes more than 19 universities, corporate and international partners.
Aquarius's three-year mission, targeted for launch in September 2008, is the first satellite mission specifically designed to provide monthly global maps of how salt concentration varies on the ocean surface. Variations in ocean surface salinity are a key area of scientific uncertainty. Scientists wish to better understand how these variations modify the interaction between ocean circulation and the global water cycle, which, in turn, affects the oceans's capacity to store and transport heat and regulate Earth's climate. The mission seeks to determine how the ocean responds to the combined effects of evaporation, precipitation, ice melt and river runoff on seasonal and interannual time scales, and their impact on the global distribution and availability of fresh water.
Dr. Gary Lagerloef of Seattle's Earth and Space Research is the principal investigator. More than 17 universities, corporate and international partners will be involved in the mission, including Argentina's Comision Nacional de Actividades Espaciales. NASA will provide the Aquarius salinity sensor, project management, launch services and science data processing. Argentina will provide the spacecraft, additional instruments and mission operations.
Hydros will make unprecedented measurements of Earth's changing soil moisture and the freeze/thaw status of the land surface that together, define the state of Earth's hydrosphere. This state links the water, energy and carbon cycles over land. Hydros measurements will open new frontiers in our understanding of how these global cycles work together in the Earth system.
Numerical models used for day-to-day weather prediction need soil moisture estimates as initial conditions for forecasts. Incorporating real observations into these models will significantly improve forecast accuracy. Soil moisture is among the top terrestrial environment measurement requirements of the Departments of Defense and Transportation because of the impact on land navigation and aviation weather.
Contributing partners for the Hydros mission, in addition to NASA, include the Canadian Space Agency and the Department of Defense. The Hydros science team draws from several universities, NASA centers, research and operational branches of federal agencies. The principal investigator is Dr. Dara Entekhabi of the Massachusetts Institute of Technology, Cambridge, Massachusetts.