Ozone Hole Recovery Could Modify Southern Hemisphere Climate
29.04.2008 - Other
Scientists from the University of Colorado at Boulder, the National Oceanic and Atmospheric Administration and National Aeronautics and Space Administration claim that if the stratospheric ozone hole were to recover, the southern hemisphere's climate, including that of Antarctica, could be subject to big change.
It is well established now that Earth's average surface temperatures have been increasing, while those of Antarctica's interior have cooled down. However, it is now believed that full recovery of the ozone hole over Antarctica to its pre-1969 levels could cause the continent's cooling trend to turn warmer.
Using a supercomputer model to cross climate and stratospheric ozone chemistry, scientists found that ozone level recovery would cause the polar region's lower stratosphere to absorb more harmful ultraviolet radiation from the sun.
Consequences of ozone level recovery:
- Break down of large-scale atmospheric circulation patterns during the austral summer, allowing warm air masses to enter Antarctica's interior from the north;
- Weakening of strong westerly winds that blow around Antarctica and stop the warm air masses from entering the continent's interior;
- Increase of air temperature 6 to 12 miles above Earth's surface by as much as 16 degrees Fahrenheit and reduction of the strong north-south temperature gradient.
However, Antarctica is not the only region at risk. A seasonal shift in large-scale circulation patterns could affect the entire Southern Hemisphere's climate. But the influence of stratospheric ozone recovery will depend on the future rate of greenhouse gas emissions. Faster greenhouse gas emissions or longer emissions production could dwarf the climatic modifications expected to occur after ozone recovery.
