Reviews of Web Sites on the Ozone Layer and the Ozone Hole
(accessed 11/9/2017)
Stratospheric Ozone Depletion (Centre Interprofessionnel Technique d’Etudes de la Pollution Atmosphérique)- Austen
This website covers a variety of information about ozone in the stratosphere. The information presented first covers the importance of ozone in the stratosphere and the different types of ultra-violet light that it absorbs. There is a section explaining how ozone is created, as well as how ozone concentrations have changed due to people. A current (2011-2012) image, from NASA, taken at different times of day is presented to show the changes in ozone concentration above the Antarctic. A table is included to present the deficit of ozone in different areas of the globe. The website also provides a list of actions that have been taken to prevent the depletion of ozone and a theory of the ozone possibly returning to normal levels. I believe this website has credible data. The website lists NASA and World Meteorological Organization as references. I was not too surprised by the data presented on this website, but it did provide a wide variety of data. The material presented was technical but digestible.
Ozone Hole poster (NASA) - Caitlin
NASA has made a poster about the ozone layer. They provide information on what the ozone layer is, the chemistry behind it, how theozone holeis formed and how to measure the ozone in the Earth's atmosphere. A graph is also given which illustratesozone depletion up until 2008. Beginning in 2009,they begin afuture projection of the path that could occur based on NASA satelliteobservations.
This information is helpful in understanding the basics of what the ozone layer is and how it pertains to chemistry. Since NASA provided the information, I feel it is reliable and accurate.
Ozone Layer Protection (EPA) – Matt
This website covers the following topics: Ozone layer science, Addressing Ozone Depletion, Adapting to a Changed Ozone Layer, Phasing out Ozone-depleting Substances and Managing Refrigerant Emissions. This website provides both basic and detailed information on each section as well as links within section to provide more detail. For example, a word like chlorofluorocarbons (CFCs) is highlighted and by clicking on the word it provides a concise definition. The website offers information on the Montreal Protocol, the first step in international efforts to protect the stratospheric ozone and the numerous amounts of amendments being made to drastically cut ozone-depleting substances. Overall, I think the information is accurate and up-to-date as it comes from an established agency, the USEPA (United States Environmental Protection Agency).
The Ozone Layer (NOAA) – Tiffany
The website focuses on the roles of stratospheric ozone and the harm of tropospheric ozone. The Ozone Layer (stratosphere) is what prevents damaging ultra-violet sunlight from reaching the Earth's surface. However, the Ozone Layer is said to deplete during the Antarctic spring. The website mentions the cause for this depletion is due to carbonfluorocarbons (CFCs), carbon tetrachlorides, and methyl chloroforms that are found in applications such as refrigeration and air conditioning. An international agreement has been made called the Montreal Protocol on Substances that Deplete the Ozone Layer. Improvements have been made and the Ozone Layer is expected to recover in the next 50 years. The information given on the website is strictly the basics and fails to give an explanation as to how CFCs are harmful to the ozone layer and, also as to how ground ozone, "smog", is created.
Stratospheric Ozone, the Protector (UCAR, University Corporation for Atmospheric Research) - Brandon
The website covers a very basic understanding of the areas of the atmosphere where ozone is helpful for biological life. It also briefly talks about how different UV radiations (UV-A and UB-B) affect biological life and how the ozone layer stops incoming harmful solar radiation. It touches on how ozone can be destroyed by certain chemical species such as chlorofluorocarbons (CFC’s) and how these are mainly from anthropogenic sources (human Sources). It also shows a generalized reaction scheme for how a CFC molecule (that travels to the upper stratosphere) is irradiated by sunlight and how it breaks down and reacts with O3 molecules in the stratosphere ultimately leading to the creation of O2. The website does a clear job of showing how and why the Antarctic regions have the highest threat level for ozone depletion and also how seasonal variability shows differences in ozone concentrations. It also discusses ways the scientific community (at the time when this phenomenon was first observed) took preemptive steps to understand and stop the ozone depletion, by specifically targeting CFC’s. I thought the website was a good starting point for anyone that wishes to have a basic understanding of how the ozone layer is degraded and where the degradation is taking place. It also does a good job of showing how a human activity can lead to dramatic consequences that they may not be aware of at the time. The figures represented in the website are also easy to follow and have adequate information.
Ozone Watch (NASA) – James
The home page starts out by giving the viewer videos of the progression of the ozone hole in a given year. The data sources paragraph gives the instruments used to obtain data on the ozone hole and track the increase and decrease of the hole throughout the year. The ozone facts paragraph gives the user an overview of what ozone is, how it is measured and what the ozone hole is. On the left side of the website tables show the area of the ozone hole in a given month, how much ozone is in the stratosphere, and the temperature of the stratosphere. Tabs at the top of the website give data about the ozone hole. The ozone maps tab shows how the ozone has increased and decreased since measurements have been taken. The ozone facts tab gives the viewer information on good ozone and bad ozone. The multimedia tab shows the viewer different view of the ozone layer as it resides in the different hemispheres. The education tab gives assignments for different grade levels to learn more about the ozone layer.