NASA's Global Hawk unmanned aerial vehicle is in the western Pacific region on a mission to track changes in the upper atmosphere and help researchers understand how these changes affect the earth's climate.
According to NASA, the Airborne Tropical Tropopause Experiment (ATTREX) is a multi-year airborne science campaign.
NASA says ATTREX will measure the moisture levels and chemical composition of upper regions of the lowest layer of the earth's atmosphere, a region where even small changes can significantly impact climate. Scientists will use the data to better understand physical processes occurring in this part of the atmosphere and help make more accurate climate predictions.
ATTREX is studying moisture and chemical composition from altitudes of 55,000 feet to 65,000 feet in the tropical tropopause, which is the transition layer between the troposphere, or the lowest part of the atmosphere, and the stratosphere, which extends up to 11 miles above the earth's surface, NASA notes. Global Hawk is carrying instruments that will sample the tropopause near the equator over the Pacific Ocean.
‘Better understanding of the exchange between the troposphere and stratosphere and how that impacts composition and chemistry of the upper atmosphere helps us better understand how, and to what degree, the upper atmosphere affects Earth's climate,’ comments Eric Jensen, ATTREX principal investigator at NASA's Ames Research Center in Moffett Field, Calif.
NASA reports that last year, for the first time, ATTREX instruments sampled the tropopause region in the northern hemisphere during the winter, when the region is coldest and extremely dry air enters the stratosphere. Preparations for the mission started in 2011 with engineering test flights to ensure the aircraft and its research instruments operated well in the extremely cold temperatures encountered at high altitudes over the tropics.
ATTREX conducted six science flights totaling more than 150 hours last year, NASA notes.