Than Thought
May 18, 2004
Chemistry Per. 5
(April 26, 2004)
Recently, NASA has conducted studies which help to prove the relationship between Arctic ozone loss and changes in the temperature if the Earths stratosphere. Considering the damage done to the ozone the dangers of the ultra violet radiation is more threatening than ever to the Earths surface. The results of the conducted tests led researchers to believe that the depletion was due not only to industrial chlorine and bromine, but also these changes in the stratospheric pressure.
Surprisingly, when scientists predicted the sensitivity of the Arctic ozone to temperature, their end result was nearly three times less than its actual sensitivity.
This means that the stratospheric temperature may be impacting the ozone layer much more than researchers ever expected.
Studies were conducted taking more than 2,000 balloon measurements, over about twelve years. The outcome supported that during Arctic winters the amount of ozone loss was directly related to the amount of air exposed cold enough to cause the formation of polar stratospheric clouds; which further always reactions occur on the surface of these clouds changing chlorine from uncreative forms into other forms that quickly eat away at the ozone. In addition to this discovery, it was found that every degree (Kelvin) colder has the ability to lead to a additional five percent destruction of the ozone.
Scientists are constantly trying to figure out why this cooling occurs. Although nothing is for sure, a number of theories have been thought up.
These include the rising levels of greenhouse gases, a feedback between ozone depletion and stratospheric temperature, and natural variability. The amounts of greenhouse gases, such as carbon, have risen over the past few years; these gases trap heat near the Earths surface, warming the surface, which prevents heat from reaching the stratosphere, overall cooling the upper atmosphere.
Luckily, it is believed that the amount of stratospheric chlorine and bromine have begun to lower. This is partially due to the Montreal Protocol, signed in 1987 world wide, restricting the amount of chlorofluorocarbons produced. This is thought to be the beginning of the cleansing process, hopefully allowing the ozone layer to recover. .
