The thinning or reduction of ozone depletion is most prominent in the polar regions, especially over antarctica. In fact, global warming, acid rain, ozone layer depletion, and groundlevel ozone pollution all pose a serious threat to the quality of life on earth. Ozone layer depletion, is simply the wearing out reduction of the amount of ozone in the stratosphere. Free oxygen atoms can recombine to form oxygen molecules but if a free oxygen atom collides with an oxygen molecule, it joins up, forming ozone.
What are the causes and effects of ozone depletion. Ozone depletion and climate change environment canada. Basic ozone layer science ozone layer protection us epa. When present together in the stratosphere, chlorine cl and ozone. Calculation of depletion layer thickness by including the mobile carriers saeed mohammadi and c. Causes and effects of ozone layer depletion that are. Ozone is a gas found in the atmosphere consisting of three oxygen atoms. The atmosphere is mostly transparent to the visible except for scatter.
A dynamic equilibrium is maintained between the formation and decomposition of ozone. To the point where a seasonal hole in the ozone layer began to appear above the antarctic. Structure of the ozone layer formation of the ozone layer depletion of the ozone layer ozone layer recovery 8 of 31 lecture question where is the ozone layer and how concentrated is it. Ozone o3 is a stratospheric layer that plays important role in providing support to humans for their survival. Ozone layer depletion causes, effects and solutions 7. List of books and articles about ozone layer online. One of the main reasons for the widespread concern about depletion of the ozone layer is the anticipated increase in the amounts of ultraviolet radiation received at the surface of the earth and the. The absolute concentration of ozone in the atmosphere is very low. The formation of the ozone layer the formation of the ozone in the stratosphere region begins with the photodissociation of oxygen molecules by the solar radiation at. This exercise investigates the kinetics of ozone formation and depletion in the atmosphere.
First you will use excel to determine the concentration profile of ozone in the atmosphere. Ozone layer depletion is the thinning of the ozone layer present in the atmosphere. Chlorofluorocarbons ozone depletion occurs when the natural balance between the production and destruction of stratospheric ozone is disturbed. The ozone layer has been depleted gradually since 1980 and now is about an average of 4% lower over the globe. The ozone hole and its causes 12observations on ozone layer 14depletionobservation 1 15observation 2 17misconceptions about the ozone layer 18depletionbibliography 19 11 12. Depletion of o3 can increase uv radiation entering earth surface. The ozone layer resides in the stratospheric layer of the earths atmosphere. Why is it important that the destruction process be. It is revealed that introduction of chloroflourocarbons cfcs in the environment is the most rated cause.
These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants. The depletion region acts like a wall between ptype and ntype semiconductor and prevents further flow of free electrons and holes. In this creationdestruction process the amounts of ozone molecules created and destroyed are roughly equal, so that the total amount of ozone in the atmosphere is nearly constant. How severe is the depletion of the antarctic ozone layer. This radiation could have seriously damaging effects on germinating crops and on the photoplankton of the oceans. Ozone layer research and technical resources us epa. In the lower atmosphere troposphere, ozone is formed in a different set of. The ozone layer in the upper atmosphere absorbs most of the harmful ultravioletb uvb radiations from the sun.
Oct 12, 2017 along the years, many environmentalists and scientists have been wondering about what causes ozone depletion. According to environmental scientists, the cfcs chlorofluorocarbons and oxides of nitrogen, when released from lower atmosphere reach the stratosphere and destroy the ozone layer. Ozone depletion, montreal protocol and kigali agreement. It is revealed that introduction of chloroflourocarbons cfcs in the environment is the most rated cause of said depiction. How large is the depletion of the global ozone layer.
Let us see some of the important causes and effects of ozone layer depletion. The causes, mechanism and bioeffects of ozone layer depletion on humans were addressed. Electrons and holes diffuse into regions with lower concentrations of electrons and holes, much as ink diffuses into water until it is uniformly distributed. Bromine can also act as a catalyst to destroy stratospheric ozone. The depletion region is also called as depletion zone, depletion layer, space charge region, or space charge layer. The earths stratospheric ozone layer plays a critical role in absorbing ultraviolet radiation emitted by the sun. It is an essential factor for many global, biological and environmental phenomena.
But many researchers do not agree with these predictions,14 and express their. Ozone layer and the formation of the ozone hole aa. One chlorine can destroy 100,000 molecules of ozone. Ozone layer depletion cause, effects, and solutions. There is a steady decline of about 4% in the total volume of ozone in earths stratosphere.
All of us are aware of how the concern related to depletion of ozone layer and the ozone hole, which also led to the ban of many chemicals such as the chlorofluorocarbon cfc. Ozone is unstable molecule and maintains a balance between its formation and removal. Scientists have explored variations and its depletion in larger amounts in the poles which is commonly termed as ozone hole. However, various factors have led to the depletion and damage of this protective layer. Maybe we do not realize this, but ozone layer depletion is a severe problem that affects our whole planet. The ozone layer is a belt of the naturallyoccuring gas ozone that sits at an altitude of between 15 and 30 kilometers above the earth. The formation of end products essentially remove cl from the ozone depletion process. In semiconductor physics, the depletion region, also called depletion layer, depletion zone, junction region, space charge region or space charge layer, is an insulating region within a conductive, doped semiconductor material where the mobile charge carriers have been diffused away, or have been forced away by an electric field. Stratospheric ozone production earth system research. The obligations are general and contain no specific limits on chemicals that deplete the ozone layer. Dramatically every spring you may have heard this called the ozone hole. Stratospheric ozone depletion, ultraviolet radiation and health. The average depletion exceeds the natural variability of the ozone layer. Within the stratosphere, the ozone layer is the portion that contains the highest.
Formation and depletion effect of the montreal protocol on stratospheric cl sunlight incident on earth is very roughly. Ozone layer depletion daily current affair article for. Ozone depletion consists of two related events observed since the late 1970s. Ozone layer depletion is one of the major environmental issues which get thin day by day by the increasing pollution. A catalyst is a compound which can alter the rate of a reaction without permently being. The severe depletion of the antarctic ozone layer known as the ozone hole occurs. This page provides links to research efforts led by organizations such as the national oceanic and atmospheric administration, the united nations environment program, an. There are many situations where human activities have. Global warming and ozone layer depletion are two different problems see the sidebar misconceptions about global atmospheric change on page 95. It occurs in the concentration of about 10 ppm in the form of layer at varying heights in stratosphere the thickness of ozone layer is measured in dobson units, where 1 du. The latter phenomenon is referred to as the ozone hole. Twenty questions and answers about the ozone layer. The ozone layer prevents most ultraviolet uv and other highenergy radiation from penetrating to the earths surface but does. Ozone depletion is allowing the uv radiation to earth surface.
There are many situations where human activities have significant effects on the environment. Ozone depletion facts and information national geographic. The severe depletion of the ozone layer in any particular area is called ozone hole. Ozone layer the ozone layer is basically naturally occurring gas in the region of stratosphere where ozone particles are accumulated 2. The increase in the levels of uv rays lead to high rate of skin cancer and eye related problems. Solar ultraviolet radiation creates an ozone layer in the atmosphere. Nearly 500 organizations, teams, and individuals from 40 countries have received stratospheric ozone protection awards for their exceptional leadership, personal dedication, and technical achievements.
Global warming is caused by the greenhouse effect, which is essential to life as we know it on planet earth. B dobson and other scientists in measuring concentrations of chloride and ozone in the atmosphere g. Ozone layer depletion, its causes and its effects ozone. Depletion to ozone layer depletion does not affect a region or a country. Calculation of depletion layer thickness by including the. The world meteorological or ganization wmo, 1995 predicted that the depletion of the ozone layer peaked around 1998 and the layer would slowly recover by 2045 12. The use of cfcs not only destroys the ozone layer but also leads to global warming. Does depletion of the ozone layer increase groundlevel ultraviolet radiation.
Ozone a form of oxygen containing three atoms instead of the usual two is formed. As the depletion layer built up a different of potential appears across the junction this difference of potential at junction is called potential barrier. Ozone layer depletion, its causes and its effects free download as powerpoint presentation. The ozone hole and its causes recently, chlorofluorocarbons cfcs were used a lot in industry and elsewhere to keep things cold and to make foam and soaps. The term ozone depletion means that the destruction of o3 exceeds the creation of o3. Causes, effects and solutions of ozone layer depletion. The earths ozone layer ozone layerthe region of the stratosphere containing the bulk of atmospheric ozone. The ozone layer is responsible for absorbing harmful ultraviolet rays, and preventing them from entering the earths atmosphere. It contains high concentrations of ozone o3 relative to other parts of the atmosphere. Ozone is unstable and decomposes to molecular oxygen. Ozone is formed in the atmosphere when energetic ultraviolet uv radiation dissociates molecules of oxygen, o 2, into separate oxygen atoms.
Causes and effects of ozone layer depletion that are truly dangerous. The main things that lead to destruction of the ozone gas in the ozone layer. Ozone in the ozone layer is formed by the action of solar ultraviolet light on oxygen. The chlorofluorocarbon and the halons are potent ozone depletors. The production of ozone near the surface does not significantly contribute to the abundance of stratospheric ozone.
Formation, depletion and montreal protocol youtube. In the last thirty years, it has been discovered that stratospheric ozone is depleting as a result of anthropogenic pollutants. The ozone depleting effect of refrigerants is important, because the ozone layer filters out ultraviolet uv radiation, which might otherwise reach the surface of the earth. They are separate problems, but, as has been seen, there are links between each. Ozone depletion is primarily caused by human activities. The natural distribution of ozone around the earth is. At the end of 20, 258 projects have been committed for an. Fossil fuel combustion is a primary source of pollutant gases that lead to tropospheric ozone production. The layers which occupy the lower part of the atmosphere removes the unwanted pollutants from the earths surface. One of the main reasons for the widespread concern about depletion of the ozone layer is the anticipated increase in.
Cfcs are extremely stable, and they do not dissolve in rain. How is a depletion layer formed in a pn junction diode. With both the formation and destruction processes for ozone driven by. Ozone layer importance, depletion, effects and protection. The ozone layer depletion can cause many types of cancer to other animals also. This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. Ozone layer vedio series for all competitive exams duration. One of the main reasons for the widespread concern about depletion of the ozone layer is the anticipated increase in the amounts of ultraviolet radiation received at the surface of the earth and the effect of this on human health and on the environment. The ozone layer is mainly found in the lower portion of the stratosphere.
Another most feared aspect of pollution is depletion of ozone layer of the stratosphere. What are the mechanisms that chapman missed to destroy ozone. Project report on ozone depletion environmental pollution. Approximately 90 percent of the atmospheres ozone occurs from 1018 km 611 miles to. Timeline of stratospheric ozone depletion and observations. Scribd is the worlds largest social reading and publishing site. Ozone hole ozone depletion at south pole polar vortex and ozone depletion are two distinct but related phenomena. What is ozone layer, how it is formed, causes and effects.
Ozone is formed throughout the atmosphere in multistep chemical processes that require. Stratospheric cooling creates a more favourable environ ment for the formation of polar stratospheric clouds pscs. Ozone ozone is a simple molecule of three oxygen atoms and it is present in the two lowest layers of the atmosphere troposphere and stratosphere. The decrease in the thickness of the ozone layer of formation of hole in it is called ozone depletion. Ozone depletion is the process of destruction of the ozone layer which can cause adverse effects on the living forms by many pollutants releases out from the vehicles, industries etc.
Coulomb force from ions prevents further migration across the pn junction. Depletion of this layer by ozone depleting substances ods will lead to higher uvb levels, which in turn will cause increased skin cancers and cataracts and potential damage. Stratospheric ozone protection awards since 1990, epa has recognized outstanding achievement in ozone layer protection. The ozone layer lies approximately 1540 kilometers 1025 miles above the earths surface, in the stratosphere. Ozone layer, region of the upper atmosphere, between roughly 15 and 35 km 9 and 22 miles above earths surface, containing relatively high concentrations of ozone molecules. Ozone depletion, montreal protocol and kigali agreement ozone depletion ozone o 3 forms a layer in the stratosphere, between 10 to 50 km above the earth, thinner in the tropics around the equator and denser towards the poles. The only practical approach to stopping the destruction of the ozone layer is to reduce the. Winds efficiently mix the troposphere and evenly distribute the gases. The ozone layer was discovered in 19 by the french physicists charles fabry and henri buisson. Pdf causes of ozone layer depletion and its effects on. During the vienna convention negotiations, countries discussed a possible protocol that would provide specific targets for certain chemicals, but no consensus was reached. By definition, ntype semiconductor has an excess of free electrons compared to the ptyp. It is formed of three oxygen atoms giving it the chemical formula, o3.
Ozone layer is a most important layer for the existence of the earth. B dobson inferred correctly that the cause of the warm stratosphere was heating by the absorption of ultraviolet solar radiation by ozone, and he set out to. Learn more about the process, causes, and effects of ozone layer depletion. If the use of cfcs and other ozone destroying chemicals are banned, it is hoped that ozone depletion may be reduced. Due to over greenhouse effect the temperature of the earth. Formation of ozone ozone, uv and aerosol studies rmi. Generally, we find thinning or depletion of the ozone layer to the extent of ozone hole creation over the southern pole i. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface causes. Depletion of stratospheric ozone o3, as commonly known as the hole in the ozone layer, is an issue of international concern. Unlike pollution, which has many types and causes, ozone depletion has been pinned down to one major human activity.
Ozone and environment ozone o3 a gas composed of three atoms of oxygen bluish gas that is harmful to breathe nearly 90% of the earths ozone is in the stratosphere and is referred to as the ozone layer ozone absorbs a band of ultraviolet radiation called uvb ozone depleting substances ods. Ozone depletion, gradual thinning of earths ozone layer caused by the. Uvb and uvc are absorbed by the destruction and formation of atmospheric ozone. Ozone layer is also naturally broken down but there is a balance between its formation and natural depletion. The ozone depletion process begins when cfcs and other ozone depleting substances ods are emitted into the atmosphere1. They have been debating this problem and its causes for a while now, trying to diminish the effects of climate change. What is ozone, how is it formed, and where is it in the atmosphere. Access information on research and technical resources related to ozone layer science. The earths ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 to 30.
Cfcs, hcfcs, halons, methyl bromide, carbon tetrachloride, and methyl chloroform. Formation, depletion and montreal protocol youtube lecture handouts. A region of the considerable ozone depletion is named an ozone hole. Frederick, in encyclopedia of atmospheric sciences second edition, 2015. Notes on ozone layer grade 10 science the atmosphere. Selvakumar abstracta useful analytical approximation for depletion layer thick ness, which takes into account the effect of mobile carriers under high forward bias is presented. Let us dig deep into what is ozone layer, how it is formed, causes and effects of ozone depletion. The ozone loss is very small near the equator and increases with latitude toward the poles. In this entry we present the data on ozone layer depletion, signs of recovery, emissions. Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation. Low temperatures, increase in the level of chlorine and bromine gases in the upper stratosphere are some of the reasons that leads to ozone layer depletion. Changes in atmospheric ozone amounts and ultraviolet radiation.
Recently the depleted ozone concentration was detected above arctic, western europe. This layer absorbs the radiations and prohibits them from entering the outer surface of the earth. Lets have a look at some of the solutions to ozone layer depletion. The ozone layer is a protective shield that blocks the suns harmful ultraviolet rays. The electrons which had migrated across from the n to the p region in the forming of the depletion layer have now reached equilibrium. It has been found that this protective ozone layer is getting depleted because of the presence of cfc chlorofluorocarbon compounds. Causes of ozone layer depletion and its effects on human. Case study depletion of ozone in the atmosphere the work of g.
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