Winds Trapping Pollutants, Solar Storms Blamed for Arctic Ozone Loss
WASHINGTON — Ozone levels over the Earth's far north dipped sharply early last year when polar winds trapped nitrogen pollutants, researchers reported Tuesday.
The sun contributed to the problem, sending out a storm of particles that bombarded the Earth and helped generate some of the ozone-destroying chemicals, according to the report in Geophysical Research Letters.
Declines in ozone over the South Pole have raised concern in recent years. They were blamed on chemicals used in aerosol sprays. Since those chemicals were widely banned, ozone levels have risen in the Antarctic.
Ozone, a form of oxygen, helps protect the Earth from some of the damaging ultraviolet radiation from the sun. The reduction of ozone has led to fears of more skin cancer and other problems in affected areas.
The decline had been less dramatic in the north, but in February and March of 2004 a decline of up to 60 percent was measured, according to a team of researchers led by Cora Randall of the University of Colorado at Boulder.
"This decline was completely unexpected," Randall said in a statement. "The findings point out a critical need to better understand the processes occurring in the ozone layer."
Winds 20 miles above the Earth's surface became much stronger than usual, the researchers said. Those winds formed a vortex, or circle, allowing nitrogen oxide and nitrogen dioxide gasses that had formed as a mass of energetic particles bombarded the Earth solar storm in the fall of 2003 to descend and react with the ozone layer.
The 2004 ozone decline occurred over the Arctic and the northern areas of North America, Europe and Asia.
The research was funded by NASA, the European Union Commission and the European Space Agency.
Working with Randall in the study were researchers from the United States, Canada, Norway and Sweden.
Source: Associated Press