The ozone layer has an important role in absorbing certain wavelengths of incoming solar ultraviolet light (Solomon S., 1999). The absorption of solar radiation is important in preventing any effects that these rays could have on the health of humans, animals, and plants (Solomon S., 1999). At the beginning of the twentieth century, we began seeing a decrease in the ozone layer as a result of man-made pollution (Solomon S., 1999). This has been due to greenhouse gases and certain chemical emissions called ozone-depleting substances (OCDSss) and in particular chlorofluorocarbons (Stone K.A., 2018). This has been a cause of concern in recent years due to the possible detrimental effects on humans and the ecosystem.
In the article “On the Identification of Ozone Recovery”, it has been seen that there is a decline in ozone-depleting substances leading to the stratospheric ozone displaying signs of healing in the Antarctic region (Stone K.A., 2018.). This is largely due to the Montreal Protocol that was adopted to phase out ozone-depleting substances (Wilka C., 2018). This was an international treaty that phased out the production of many human-made compounds that were responsible for stratospheric ozone destruction (Solomon S. 2016). The Montreal Protocol is considered one of the most important and successful international agreements (Solomon S. 2016). The treaty was created after it was observed that anthropogenic chlorofluorocarbons caused a showed a sharp, unexpected ozone decline in the Antarctic during the 1980’s (Wilka C., 2018) creating an ozone hole. The ozone hole is a result of the thinning of the ozone layer is the due to heterogeneous reactions on cold polar stratospheric cloud surfaces (Wilka C., 2018). It is shown from the evidence, that the upper stratospheric ozone has increased due to a recovery from halogen induced losses (Ball W.T., 2018).
A focus of ozone research is due to the Montreal Protocol and the expected decline in equivalent effective stratospheric chlorine (EESC) (Stone K.A., 2018.). The ozone has begun its slow recovery process and has increasingly become more detectable in observations. In a joint study done by the Department of Earth, Atmospheric, and Planetary Science, Massachusetts Institute of Technology and National Center for Atmospheric Research (Stone K.A., 2018.), they were able to observe ozone recovery in the Antarctic region through a series of models used to help identify factors that contribute to the continued recovery (Stone K.A., 2018.). They focused on higher altitudes and the global stratosphere and evaluated two processes that could influence ozone recovery which was dynamical variability and solar proton events (SPEs) (Stone K.A., 2018.). The results were that the upper stratospheric ozone is expected to display the largest recovery at high latitudes during colder seasons (Stone K.A., 2018.) and that solar proton events need to be taken into account when evaluating upper stratospheric ozone recovery (Stone K.A., 2018.).
Based on previous research, it has also shown that heterogeneous chemistry plays in the continued recovery and depletion of the ozone layer. Through a study that examined the impact of volcanic eruptions we able to see what factors can affect the potential future ozone depletion or recovery (Wilka C., 2018). It was proven that volcanic eruptions increase stratospheric aerosols and which in turn enhance ozone depletion. (Wilka C., 2018). Done through a series of model simulations, they indicated that several large eruptions increased the rate of ozone depletion from 1979 to 1998, while a series of moderate eruptions after 2004 slowed the rate of ozone recovery from 1999 to 2014 (Wilka C., 2018).
Now about 30 years after Montreal Protocol came into effect, the Antarctic ozone hole now shows signs of recovery. Over time, the rate of stratospheric ozone depletion has slowed enough to the point where the ozone abundance over Antarctica has begun to increase (Solomon S. 2016). This is due to the decrease in chemicals that contribute to the heterogeneous reactions that occur on cold polar stratospheric cloud surfaces (Wilka C., 2018).
The outcomes of studies being done on this topic, mean that there is continued research due to its relevance. Through climate models, continued monitoring and the documenting of the process of recovery in the ozone layer (Solomon S. 2016) we are able to slowly decrease the effect of chemical emissions and prevent future depletion of the ozone layer.
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