Secrets of ozone loss high in sky
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. We’re Block and Byrd for Earth & Sky.
Very cold air temperatures freeze-dry most of the air going into the stratosphere, thereby removing water. As Earth’s climate changes, the amount of water in the stratosphere is also expected to change. But exactly how water gets into the stratosphere is still a major scientific question.
Paul Newman also told Earth & Sky: “The tropics is a particularly wonderful place to measure because all the gases that get into the stratosphere from the lower atmosphere here get into the stratosphere in the tropics.”
Additional Teacher Resources
Ozone Science: The Facts Behind the Phaseout
The Earths ozone layer protects all life from the suns harmful radiation, but human activities have damaged this shield. Less protection from ultraviolet light will, over time, lead to higher skin cancer and cataract rates and crop damage. The U.S., in cooperation with over 160 other countries, is phasing out the production of ozone-depleting substances in an effort to safeguard the ozone layer.
NASA: Good News and a Puzzle
Think of the ozone layer as Earths sunglasses, protecting life on the surface from the harmful glare of the suns strongest ultraviolet rays, which can cause skin cancer and other maladies.
