Air Date: Week of February 13, 2004

Living on Earth’s Jennifer Chu reports on a study that suggests air pollution may find cover in clouds.

Transcript

CURWOOD: It’s Living on Earth, I’m Steve Curwood. Coming up: public safety and official accountability in coal country. We have a special investigative report. First this note on emerging science from Jennifer Chu.

[SCIENCE NOTE THEME]

CHU: For a number of years, scientists have suspected that clouds carry more pollution across the sky than wind alone. Now, a new study by NASA scientists demonstrates this is true. Researchers took air samples of cloudy and clear air during twenty flights near the coastline of Asia. They checked for pollutants such as carbon monoxide, carbon dioxide, and methane. And they found almost a third more pollutants in the cloud cover than in the clear.

Scientists believe this occurs because human activities like burning fuel for heat or industrial purposes emit such pollutants as carbon monoxide. Cold fronts move in and lift warm, polluted air up. This same lifting of warm air causes the cloud formations. So the pollution of air is lifted right into the clouds. The discovery that clouds carry a heavier load of pollution is important in understanding regional flow of contaminated air.

Recently, satellites have begun to monitor the flow of pollutants such as ozone and carbon monoxide. But the satellites are unable to get as accurate a reading when blocked by cloud cover. So researchers conclude that based on this study, both satellites and actual air testing will be necessary to monitor the flow of pollution from one area to another. That’s this week’s note on emerging science, I’m Jennifer Chu.