Today's science vocab lesson: tropopause. It's the atmospheric boundary between the troposphere, where ozone exists as a harmful greenhouse gas, and the higher-up stratosphere, where the same gas plays an important role in protecting the Earth from the sun's UV rays. And that boundary region is about to get some attention from a drone. Later this month, NASA will begin a multi-year study during which an unmanned Global Hawk drone will fly into the tropopause, typically found about eight to 11 miles above Earth—to study how water vapor and ozone interact, reports LiveScience.
Scientists suspect that big storms sometimes push water vapor up into the stratosphere, where chemical reactions between water and free radicals may destroy the protective ozone. But because no one fully understands what goes on in the tropopause, scientists also don't know much much water vapor makes it into the stratosphere or what happens to it. The hope is that the Airborne Tropical Tropopause Experiment will fill in those blanks. (Read more Airborne Tropical Tropopause Experiment stories.)