Our world is surrounded by three levels of atmosphere all made of a basic 3 atom oxygen. The top most layer is called the Ionosphere can be found 30 miles above sea level, which could only be seen from a space craft. The second layer is the Stratosphere which ranges from 6 mile to 30 miles above sea level. The ozone layer is found in the Stratosphere. The last level of atmosphere is the Troposphere. This is the air that we see and breathe, this is also where most of our pollution is found. The actual ozone hole is located over Antarctica, because of the polluted chemicals that are emitted into our air are heavier than atmospheric chemicals. As the weather in the Antarctic region reach extreme cold temperatures it becomes a gathering area for the polluted chemicals to converge creating a thin hole like affect in the protective Stratosphere.
Scientists monitor the size and thickness of the ozone hole using a system called the Dobson Unit of Measurement. “This system is named after G.M.B. Dobson, one of the first scientists to investigate atmosphere ozone. He designed the ‘Dobson Spectrometer’ the standard instrument used to measure ozone from the ground” Carver (1998). The Dobson measurement unit condenses a unit of air to 0 degrees Celsius and 1 atm (atmosphere pressure) to form a slab of atmosphere 3mm thick. This 3 mm slab atmosphere corresponds to 300 DU (Dobson units). The lowest recorded measurement was taken October 6, 1991 near the South Pole where the record was set at 111 DU. The DU measurement for the tropics stays at about 275-300 DU on a year round bases.
Scientist are not only able to measure the thickness of the ozone layer but they also monitor the phyiscal size of the hole. Shown here in the graph created by the Climate Prediction Center on behalf of the National Weather Service. This graph shows the average size of the hole in million square kilometers. In a 10 years span the size of the ozone hole had increased from 22 million square kilometers to 28 million square kiolmeters in the year 2003 (2002). 22 to 28 does not seem like a large increase in numbers, but considering that it is measured in million square kilometers that is a substantial increase in its physical size.
We have created our own monster with our advances in convenient lifestyles. Could you imagine a life without transportation, air conditioning or refigeration? The chemicals that are used in these two systems are one of the main reasons our ozone layer is endangered. Sommervile (1998) author of The Forgiving Air: Understanding Enivronmental Change wrote about “Thomas Midgley, Jr. who created his greatest achievement in industrial chemistry. As a chemist he was largely self-taught. At the age of 33, while working at General Motors Research Corporation, he discovered the value of tetraethyl lead as a gasoline addditive” (p13).. He was then put to work to create a safe refrigerant. In 1928, Midgley invented a chemical called chlorofluorocarbon. Chlorofluorocarbon also known as CFC’s were considered a miracle chemical, nontoxic, non corrosive, the perfect chemical. It was not only used in refrigirators but also in industrial cleaning solvents and in 1928, DuPont Chemical Company was making tons of CFC’s
Changes must be made in the way we treat our environment and chose changes are being made with the Montreal Protocol. Sommeville (1998) also explained about “An internation conference that was held in Montreal, Canada, in September 1987. The resulting agreement, the Montreal Protocol, ratified by 57 countries, put in place a global framework for phasing out the production of CFC’s and halons on an agreed-upon schedule. It had been clear that although CFC’s were the main culprit, other compounds also contributed to the destruction of the ozone” (p24). The Montrol Protocol is the first step the world as taken together to save the world’s ozone layer with increased public knowledge and the Montrol Protocol recovery of the ozone layer is headed in the right direction.
Hofman (2000) director of the Climate Monitoring and Diagnostics Laboratory in Boulder, Colorado claims that “Although small variations in the severity of the ozone hole from year to year are expected, the fact that the 1999 hole was no larger or deeper than that in 1998 is good news” (p116). Atleast 50 years is the estimated recovery time to for the ozone layer to reach levels before 1980.
If we as inhabitant of this earth better understand what the ozone layer is and its functions we can better understand how to stop the destruction and to help it to recover. The ozone layer is our greatest protection from the sun and for our future generations and for the future of life as we know it. We have to take care of the ozone layer that takes care of us.
References
Carver, Dr. G. (1998) Dobson Unit Definition. Center for Atmosphereic Science. Cambridge
University, United Kingdom: Retrieved June 24, 2004 from World Wide Web
<http://www.atm.ch.cam.ac.uk/tour
Gleason, K. (2001). Description of Stratoshpere Ozone Products: Stratosphere Ozone. Retrieved
June 21, 2004 from World Wide Web <
Hofman, D. (2000). Antarctic Ozone Hole Shows Beginning of Recovery Process. Bullentin of
the American Metrorological Society. Volume 81 Issue 1 pp116
Newton, D. (1995) The Ozone Dilemma: A Reference Handbook. Santa Barbara, California.
ABC-CLIO pp4
Somerville, R. (1998) The Forgiving Air; Understanding Environmental Change. Berkeley
University of California Press. pp13, 24
