Ozone Holes: Where and Size, Bad and Good

Wei, Laurie (Author); Alelmi, Ibraheem (Author); null (Mentor); Nieh, Sen (Author)

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http://hdl.handle.net/1961/cuislandora:213314

Mechanical Engineering

Stratospheric ozone is considered a natural sunscreen that protects life from harmful ultraviolet (UV) rays from the Sun for hundreds of millions of years. Ozone holes consist of exceptionally depleted ozone in stratosphere over the Antarctic, North Pole, and Tibetan mountains with measured concentration less than 220 Dobson Units. Studies showed the incidence of skin cancer increases by 2% for each percent of ozone reduction. Chlorofluorocarbons (CFCs) and Hydrochlorofluorocarbons (HCFCs) used in HVAC and refrigeration devices are said to be the perpetrators that release chlorine when leaked to ground air, diffuse to the stratosphere, dissociate to active ions, and catalyze and destroy ozone molecules (2 O3  3 O2). Ozone depletion and ozone holes in recent decades have caught huge global attentions and worries. Banning ozone-depleting refrigerants such as CFCs and HCFCs has been enforced through international agreements for the past two decades.Why do ozone holes appear in places where little population and effectively no HVAC and refrigeration are used? Why aren't there any holes over Los Angeles, New Mexico city, Shanghai, Paris, Hong Kong, where millions of ACs and refrigerators are used? Why is the distribution of UV radiation on Earth ground is found high near the equator, where ozone layer is not thin or dilute? Why do the ozone holes shrink or expand over different seasons of the year, if they are solely man-made? Are increasing incidences of skin cancer and eyes problem are primarily caused by depletion of stratospheric ozone? People believe ozone holes are bad; can they lead to any good outcome to humanity? This paper will collect and compare scientific data and take a different approach in seeking the truths of ozone depletion and holes. The authors will strive to address some of the questions mentioned above and explain the phenomena about ozone hole, its size, its location, and any bad and good impacts and the role of depleting chemicals, CFCs.

The Catholic University of America

2019-04-09