Ozone layer ultraviolet radiation protection

Ozone absorbs ultraviolet radiation below 320 nm. It thus forms an indispensable shield in the upper atmosphere, protecting the Earth s surface from most of the potentially hazardous effects of such high-energy electromagnetic radiation. There is now increasing concern because atmospheric pollutants are depleting the ozone layer worldwide, with the most serious depletion over Antarctica as a result of seasonal variations in high-altitude air circulation. In the upper atmosphere, ozone is formed from O2 ... 

Measurements of ozone (O3) concentrations in the atmosphere are of particular importance. Ozone absorbs strongly in the ultraviolet region and it is this absorption which protects us from a dangerously high dose of ultraviolet radiation from the sun. The vitally important ozone layer lies in the stratosphere and is typically about 10 km thick with a maximum concentration about 25 km above the surface of the earth. Extreme depletion of ozone in a localised part of the atmosphere creates what is known as an ozone hole. 

Located several kilometres above the Earth s surface is the stratosphere. Here the ozone layer acts as a filter, protecting life on Earth from harmful low-wavelength ultraviolet radiation known as UV-C, which damages biological macromolecules such as proteins and DNA. In order to understand the effects of anthropogenic input into the stratosphere, the production and destruction of the ozone layer has been studied by a variety of photochemical models and experimental methods. 

Above the troposphere is the stratosphere, which reaches a height of 50 kilometers. At an altitude of 20 to 30 kilometers in the stratosphere lies the ozone layer. Stratospheric ozone acts as a sunscreen, protecting Earths surface from harmful solar ultraviolet radiation. Stratospheric ozone also affects stratospheric temperatures. At the lowest altitudes, the temperature is coolest because of the solar screening effect of ozone air at this altitude is literally in the shade of ozone. At higher altitudes, less ozone is available for shading and temperature increases all the way to a warm 0°C at the top of the stratosphere. 

Photochemical air pollution in the troposphere results from a complex interplay between sunlight and primary air pollutants emitted in ambient air that leads to the formation of ozone and other oxidizing and cye-irritaling agents. On the other hand, pollutants injected into the stratosphere by such human activities as supersonic transports (SST s) and release ofchlorofiuoro-methancs in air by their use as aerosol propellants and refrigerants may eventually reduce the protective layer of ozone from harsh solar ultraviolet radiation. Although the full impact of injected air pollutants in the stratosphere is not apparent at present, various model calculations show conclusively that the continuous future release of chlorofluoromethanes and NO (NO and N02) would result in substantial reduction of ozone in the stratosphere. 

The protective effects of an ozone layer in tile stratosphere of the earth have been known for many years. Ozone prohibits full penetration of ultraviolet radiation from the sun to the surface of the earth. Much research has been conducted and is still underway to determine the extent to which certain chemical pollutants may be destroying the ozone layer gradually and. among other factors, causing marked warming of the earth. 

Chemical kinetics is a subject of crucial environmental and economic importance. In the upper atmosphere, for example, maintenance or depletion of the ozone layer, which protects us from the sun s harmful ultraviolet radiation, depends on the relative rates of reactions that produce and destroy O3 molecules. In the chemical industry, the profitability of the process for the synthesis of ammonia, which is used as a fertilizer, depends on the rate at which gaseous N2 and H2 can be converted to NH3. 

Our atmosphere protects us from harmful ultraviolet radiation from the Sun. This damaging radiation is absorbed by the relatively thin ozone layer found in the stratosphere (Figure 14.7). 

About 12 to 15 miles (about 20 to 25 km) above the Earth s surface, a thin blanket of gas protects us from the Sun s harmful rays. The blanket is ozone, triplets of oxygen atoms bound together in molecules that absorb the Sun s ultraviolet radiation. In the 1970s, scientists discovered that the ozone layer was under attack from CFCs. 

Ozone A molecule made up of three atoms of oxygen. It occurs naturally in the stratosphere and provides a protective layer shielding the Earth from harmful ultraviolet radiation. In the troposphere, it is a chemical oxidant, a greenhouse gas and a major component of photochemical smog. 

Ozone depletion Destruction of the stratospheric ozone layer that protects the Earth from harmful effects of ultraviolet radiation. Depletion of the ozone layer is due to the breakdown of certain chlorine- or bromine-containing compounds (chlorofluorocarbons or halons), which break down when they reach the stratosphere and then catalytically destroy ozone molecules. 

Ozone layer The protective layer in the atmosphere, about 15 miles above the ground, that absorbs some of the sun s ultraviolet rays, thereby reducing the amount of potentially harmful radiation that reaches the Earth s surface. 

Ozone is O3. The ozone layer is a region of the stratosphere that contains higher concentrations of ozone than other parts of the atmosphere. The ozone layer is important for human health because it blocks ultraviolet radiation from the sun, and this helps to protect us from skin cancer. Research in the 1970s revealed that several gases used for refrigeration and other purposes were depleting the ozone layer. Many of these ozone-destroying molecules are short alkyl halides known as chlorofluorocarbons or CFCs. 

Oxidizer Chemical substance that causes oxygen to combine with another chemical substance examples include oxygen and hydrogen peroxide Ozone depletion Destruction of the stratospheric ozone layer that protects the Earth from harmful effects of ultraviolet radiation. Depletion of ozone layer is due to the breakdown of certain chlorine- and/or bromine-containing compounds (chlorofluorocarbons or halons), which break down when they reach the stratosphere and then catalytically destroy ozone molecules Ozone layer Protective layer in the atmosphere, about 15 miles above the ground. The ozone layer absorbs some of the sun s ultraviolet rays, thereby reducing the amount of potentially harmful radiation that reaches the Earth s surface PAHs Polycyclic aromatic hydrocarbons... 

Ozone is vital to life it acts like a shield, protecting the earth s surface from destructive ultraviolet radiation. A decrease in ozone concentration in this protective layer would have some immediate consequences, including an increase in the incidence of skin cancer and eye cataracts. Other long-term effects include a reduced immune response, interference with photosynthesis in plants, and harmful effects on the growth of plankton, the mainstay of the ocean food chain. 

Because ozone selectively absorbs these deleterious wavelengths of solar radiation, it serves as an ultraviolet shield. As such, stratospheric ozone helps to protect humans and other organisms on Earth s surface from some of the harmful effects of exposure to this high-energy electromagnetic radiation, hi fact, without the protective action of the stratospheric ozone layer, it is likely that... 

Above the troposphere, temperatures increase with altitude, reaching a maximum of nearly 2°C at about 50 km. This region of the atmosphere is called the stratosphere. The stratosphere contains a layer of ozone, a gas that helps shield Earth s surface from the Sun s harmful ultraviolet radiation. Ozone protects Earth by absorbing solar radiation, which raises the temperature of the stratosphere in the process. You read about the ozone layer in Chapter 1 as you began your study of chemistry. 

The ozone layer in the stratosphere forms a protective barrier against harmful high-energy ultraviolet radiation. Levels of ozone have been depleted by chemical reactions with CFCs in the upper atmosphere above the North and South Poles. 

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