The chemical reactions in the PSCs produce nitric acid. The acid forms crystals that provide additional surface area for the chlorine reactions. This also isolates the nitrogen that could otherwise be used to lock up the chlorine in nonreactive form again. As these crystals grow, they fall as precipitation, removing active nitrogen from the stratophere. This "denitrification" slows down the removal of chlorine, allowing increased destruction of ozone (details).
Wear Sunscreen-The Ozone Hole Will Not "Disappear" Soon
After the Antarctic ozone hole was discovered, the production of CFC's was banned in most countries due to the Quebec protocol and other measures. At that time, scientists predicted that ozone loss would decrease after 2010. They expected complete recovery of the ozone layer sometime around 2050. The new information about the chemistry of Polar Stratospheric Clouds and denitrification throws doubt on those predictions. While we continue to produce greenhouse gases that warm the surface and cool the stratosphere, the loss of ozone in the upper atmosphere may take a very long time to improve.
Click Here For Ozone Depletion Links
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