02-11-2006 - Earth

sagar: Author=’Abby Frank’ program=’4787′ video=”WB-57 aircraft used to make measurements of tropical air at an altitude of nearly 55,000 feet, or 16,500 meters. Measurements at this altitude will help scientists build models of future ozone depletion._JB:_ This is Earth & Sky. Throughout early February, scientists used a high-altitude aircraft to help probe the mysteries of Earth’s ozone loss and recovery.

_DB:_ Paul Newman is a lead scientist for the project. He said the purpose was to sample a hard-to-reach region of the atmosphere high up, nearly into Earth’s stratosphere. The temperature there is 130 degrees Fahrenheit below zero.

_JB:_ Newman said that, as Earth’s climate changes in this century, the stratosphere might get colder. And he spoke of the link between colder air temperatures, the amount of water in the stratosphere, and ozone depletion.

_Paul Newman:_ Now, if it gets colder at those altitudes, then you remove more of the water, and because there’s less water up there, there’s less chlorine, there will be less activation of ozone destroying compounds, and so less ozone depletion.

_DB:_ But if climate change in this century acts to warm the air …

_Paul Newman:_ If it warms up at 50,000 feet in the tropics, then you’ll be able to get more water into the stratosphere, and then you’ll form more clouds that will activate ozone depleting substances that lead to more ozone loss.

_DB:_ Even the best computer models can’t tell scientists whether global warming will create a warmer or colder stratosphere and more or less ozone loss. That’s one of the questions Newman and his colleagues are trying to explore. Our thanks today to “NASA”:http://www.nasa.gov. We’re Block and Byrd for Earth & Sky.

Written by EarthSky