Stratospheric Ozone Depletion Research

Stratospheric Ozone Depletion ResearchA) cause of Ozone on the Lower airwaveThe lower atmosphere (Troposphere) includes 75% by mass of the atmosphere (concentrated). immanent sources of Ozone in the troposphere includes lightning. Approximately 10% of all atmospheric ozone is present in the troposphere. If ozone levels reach 20ppm, they be very poisonous to humans, animals and plants. It oxidises organic tissue which disrupts the ruler biochemical reactions in the body, irritates the eyes and causes breathing difficulties. It butt end be evil to plants and agriculture, as it oxidises much more than readily then group O, killing/ muck up the agriculture and destroying it.Sources of ozone in the troposphere include diffusion from the stratosphere, internal combustion engines, petrochemical smog, by nature from lightning and photochemically when nitrogen dioxide in polluted air is decomposed by sunlight.NO2(g) NO(g) + O(g)O2(g) + O(g) O3(g)Positive cause of ozone include th at it advise kill bacteria and viruses in water and at that placeof is useful in purifying water supplies.B) Effects of Ozone in the Stratospherecontrastingly to ozone in the troposphere, Ozone in the stratosphere is essential to life on human beings, as it absorbs ultraviolet beam of light (UV) radiation which can be detrimental to living cells on earth as they can damage living tissues and cause undress cancers. Ozone in the stratosphere is commonly referenced to as the ozone shield as it protects living organisms on earth from UV rays.Ozone Reactions in the Stratosphere and their Beneficial Effects on liveness OrganismsFormation of Ozone in the StratosphereO2(g) O(g) + O(g)O(g) + O2(g) O3(g)Stratospheric oxygen absorbs UV light to form costless oxygen radicalsThe oxygen radicals ar highly reactive and combine with oxygen molecules to form an energized ozone molecule.Decomposition of Ozone in the StratosphereO3(g) O2(g) + O(g)Due to the absorption of UV radiation, the Ozone socio-economic class acts as a radiation shield by absorbing ordinary and high energy UV rays. This protects living organisms as UV radiation can admit very harmful effects on them including faeces cause sunburn on skin which can lead to skin cancer caused by a mutation in deoxyribonucleic acid cigaret form cataracts on eyesIt can kill cells due to DNA readily reacting with UV raysIt can impair photosynthesis in plantsMany moreThus without the ozone shield in the stratosphere, life in the biosphere would be dramatically impaired and destroyed by harmful UV rays.A) Functional Groups and widely distributed Structure of Compounds Classified as chlorofluorocarbonsCFCs Chlorofluorocarbons are haloalkanes in which the hydrogen atoms have been replaced by fluorine or atomic number 17 atoms.Haloalkanes are the products when alkanes react with halogens (members of group 7 of the periodic t up to(p)). CFCs globally contain chloro and flouro functional groups and no hydrogen atom s.The general structure of compounds classified as CFCs are haloalkanes whose hydrogens have been replaced by chlorine or fluorine atoms.E.g.B) Main Uses of CFCsCFCs were used as refrigerants and as propellants in aerosol spray cans. They have a variety of uses as demonstrated below.However due to the harmful effects of CFC to the environment and the ozone shield, CFCs are not used for these uses anymore.C) Reactions amidst CFCs and Ozone that Result in the Destruction of Ozone in the Stratosphere. Effects of Small Concentrations of CFCs that can Damage Large amounts of OzoneReactions mingled with CFCs and OzoneSynthetic CFCs are responsible for the destruction of the ozone shield, natural CFCs such as CH3Cl and HCl rarely reach the stratosphere as they readily oxidise in the troposphere. However, synthetical substance CFCs slowly diffuse from the troposphere into the stratosphere, where they undergo photodissociation (due to UV rays) to produce chlorine and bromine radicals tha t attack and destroy ozone molecules.e.g. CFC-11 Trichloroflouromethane (CFCl3) (Lifetime of 70 eld)1. In the stratosphere, the CFC comes into contact with petty wavelength UVCFCl3(g) + UV CFCl2(g) + Cl(g)2. The chlorine free radical then reacts with the ozone moleculeCl + O3 ClO + O23. The ClO molecule reacts with free oxygen atoms which exist naturally from UV breakdown of O2ClO + O O2 + ClThis Cl Is then regenerated and able to attack more Ozone (Step 2) therefrom further demonstrating the harmful effects of up to now one CFCThis reaction causes destruction of ozone in the stratosphere, due to the ( previously used) synthetic CFCs for refrigeration, dry cleaning etc.Small Amounts of CFCs can still do harmEvidence has shown that steady small amounts of CFCs can damage epic amounts of ozone. Firstly, CFCs generally have a long lifespan, ranging from approximately 57 (CFC-11) years to 333 years (CFC-12), and due to the fact that each Chlorine radical can be responsible for the breakdown of tens of thousands of ozone molecules, and due to their lifespan once released, even a small amount, will be around for many decades to come.In addition, most CFCs will almost definitely make their way up to the stratosphere as they cannot be destroyed at low altitudes as they are unreactive and they are insoluble in water and therefore cannot be washed out of the atmosphere by rain.Alternative Compounds for CFCs.A) Ozone Monitoring InstrumentsOzone Concentrations in the StratosphereSource Earth System Research Laboratory, 2012, Viewed 07.06.14,http//www.esrl.noaa.gov/gmd/dv/spo_oz/spototal.htmlA) Analysis of TrendsThere are a variety of trends that can be interpreted from the above diagram.establish on the info above, before the 1980s, the total ozone submergence was VERY high, at approximately 194 DU (Dobson Units), however there was a very rapid light in this concentration from 1980 1999, whereby in this 19 year period sees a 56% decrease in the amount of tot al ozone, a unusually concerning figure.On a year round basis globally, total ozone concentration have caused a 3-8% decrease in the amount of ozone, this increased in the years between 1995-200, where there was a low of total ozone concentration. However, in more recent years, 2010 to 2014 there has been a general increase in total ozone concentration, which can be inferred from the replacement of CFCs finally starting to bushel (slightly) on the total concentration of ozone, this increase based on the data is 31%.The general pattern is that the total column ozone decreases during spring time, it can be inferred that the overall concentration of ozone decreases during this time of the year. This is because in an Antarctic winter, there is no U.V light to convert the chlorine molecule Cl2 into a Cl radical, which then destroy ozone molecules, and thus the concentration of ozone is higher in winter. In spring, the U.V light converts the Cl2 into Cl which then destroys ozone in a ch ain reaction, thus decreasing the total ozone concentrationThere are various peaks in the graph, in the years of 1988, 2003, 2011 and 2013, which may be due to limitation so of the instruments used.B) Montreal Protocol EffectivenessThe Montreal protocol occurred in 1987, which the main aim was to adjudge the production of ozone depleting substances (CFCs) worldwide. A number of amendments have been adopted to further mobilise ozone depleting substances. The protocol is applied in 193 countries.The main aims of the original agreement is as followHalt the use of Halons by late 1994By the aboriginal 21st century, phase out the use of HCFCsStop manufacture of CFCs by 1996Allow for leeway with less developed countries but still ca-ca them to rid the use of these substancesThe Montreal Protocol (and amendments) has been effective as by 2006, the enjoyment of ozone depleting substances has been reduced globally by 96%. However, due to the long lives of the previously used ozone deplet ing substances, the total concentration will take hundreds of years to be completely down. However, the total concentration in the troposphere has generally been declining since the mid-1990s.BibliographyThickett, G 2006, interpersonal chemistry 2 HSC course, John Wiley and Sons, Queensland, Australia.Role of Ozone, 2013, viewed 05.06.14,http//www.easychem.com.au/monitoring-and-management/the-atmosphere/roles-of-ozoneAllen, J, 2001, invisible Radiation How it Affects life on Earth, viewed 05.06.14,http//earthobservatory.nasa.gov/Features/UVB/Environmental auspices Agency, 2010, The Process of Ozone Depletion, Viewed 07.06.14,http//www.epa.gov/ozone/science/process.htmlClean Air strategical Alliance, 2013, Chlorofluorocarbons (CFCs) and Halons, Viewed 07.06.13,http//dwb.unl.edu/teacher/nsf/c09/c09links/www.casahome.org/chlorofl.htmWelch, C 2014, The Ozone Hole, Viewed 07.06.14,http//www.theozonehole.com/cfc.htmCracknell, A 2012, Remote Sensing and Atmospheric Ozone, Viewed 07.06. 14,http//books.google.com.au/books?id=YZzGFPnaEv0Cpg=PA94lpg=PA94dq= air+4+satellite+ozonesource=blots=k3Ixvnqeupsig=Z_jW0D4jdcvG8hpjbb7d4QeUzBMhl=ensa=Xei=DpCSU-qHMsLtkQWJsIHQDQved=0CF8Q6AEwCgv=onepageq=nimbus%204%20satellite%20ozonef=falseESA, 2013, Eathnet Online, Viewed 07.06.14,https//earth.esa.int/handbooks/gomos/CNTR1-2-2.htmThe Canadian Ozone and Ultraviolet Measurement Program, 2010, Viewed 07.06.14http//es-ee.tor.ec.gc.ca/e/ozone/ozonecanada.htmEarth System Research Laboratory, 2012, Viewed 07.06.14,http//www.esrl.noaa.gov/gmd/dv/spo_oz/spototal.htmlEPA, 2013, Ozone Layer Protection Glossary, Viewed 14.06.14,http//www.epa.gov/ozone/defns.htmlBureau of Meteorology 2013, Ozone Frequently Asked Questions, Viewed 14.06.14,http//www.bom.gov.au/uv/faq.shtmlSmith, R 2008, Conquering interpersonal chemistry Fourth Edition, The McGraw-Hill Companies, NSW, Australia1 Page