Total ozone for Sept. 17, 2009
Source: NASA Daily maximum for 2009:
24 million square km (9.3 million square miles)
on September 17
The "ozone hole" is a severe depletion of the ozone layer high above Antarctica. It is primarily caused by human-produced compounds that release chlorine and bromine gases in the stratosphere. The ozone layer acts to protect life on Earth by blocking harmful ultraviolet rays from the sun.
The image at left is a view of the most recent Antarctic ozone hole, derived from satellite measurements that monitor the ozone layer. The blue and purple colors are where there is the least ozone, and the greens, yellows, and reds are where more ozone is present.
There are signs that ozone depletion is slowing in response to the 1987 Montreal Protocol, which resulted in a significant reduction in global emissions of ozone-depleting chemicals. However, climate change may cause the ozone hole to expand further[本話題由 自由之靈 於 2010-01-12 11:32:52 編輯]