Stratospheric Balloon (image) Goethe University Frankfurt Caption With stratospheric balloons researchers derive the "age" of the air from trace-gas measurements. Their results indicate that air masses are moving more slowly than predicted by climate models. Credit Andreas Engel Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.