January 10, 2013
NASA Craft To Shed Light On Climate-Related Processes In The Stratosphere
redOrbit Staff & Wire Reports - Your Universe Online
NASA has announced plans to send an unmanned, remotely-controlled research vehicle into the upper atmosphere in order to find out what impact climate change is having on our planet.The program, which has been christened the Airborne Tropical Tropopause Experiment (ATTREX), will utilize instruments on board a long-range Global Hawk aircraft to collect measurements above the tropical Pacific Ocean, the US space agency explained.
The craft, which is capable of making 30-hour flights, will be operated by the Dryden Flight Research Center at California´s Edwards Air Force Base and will reach heights in excess of 65,000 feet, they added.
“Water vapor and ozone in the stratosphere can have a large impact on Earth's climate,” NASA officials said in a statement on Wednesday. “The processes that drive the rise and fall of these compounds, especially water vapor, are not well understood. This limits scientists' ability to predict how these changes will influence global climate in the future.”
“ATTREX will study moisture and chemical composition in the upper regions of the troposphere, the lowest layer of Earth's atmosphere,” they added. “The tropopause layer between the troposphere and stratosphere, 8 miles to 11 miles above Earth's surface, is the point where water vapor, ozone and other gases enter the stratosphere.”
According to NASA, previous research has demonstrated that even slight changes in stratospheric humidity can impact Earth´s climate in big ways. Predictions about those stratospheric humidity changes carry with them a certain degree of uncertainty, however, because of scientists´ imperfect understanding of the physical processes that occur in the tropical tropopause layer. It is their hope that the ATTREX program, which will focus specifically on the area of tropopause near the equator near Central America, can change that.
"The ATTREX payload will provide unprecedented measurements of the tropical tropopause," Eric Jensen, the program´s principal investigator at the Ames Research Center in Moffett Field, Calif. "This is our first opportunity to sample the tropopause region during winter in the northern hemisphere when it is coldest and extremely dry air enters the stratosphere."
The Global Hawk that will be used in the ATTREX program has been outfitted with 11 scientific instruments, including remote sensors that will measure clouds, trace gases, and temperatures both above and below the aircraft. It will also contain devices that will measure water vapor, cloud properties, meteorological conditions, radiation fields and numerous trace gases surrounding the vehicle, according to the space agency.
Engineering test flights conducted in 2011 demonstrated that both the Global Hawk and its instruments can function well in the high altitude and extreme cold above the tropics. Six science flights are currently scheduled between January 16 and March 15, and the ATTREX team is hoping to expand the program to include remote deployments to both Australia and Guam sometime next year.
The goal of the mission is to collect data that can help “improve global model predictions of stratospheric humidity and composition,” officials said.
Image 2 (below): ATTREX will utilize instruments on board a long-range Global Hawk aircraft similar to the one pictured to collect measurements above the tropical Pacific Ocean. Credit: NASA/Tony Landis