The gaseous area surrounding the planet is divided into several concentric spherical strata (31k jpeg) separated by narrow transition zones. The upper boundary at which gases disperse into space lies at an altitude of approximately 1000 km above sea level. More than 99% of the total atmospheric mass is concentrated in the first 40 km from Earth's surface.
Atmospheric layers are characterized by differences in chemical composition that produce variations in temperature.
The troposphere (14k jpeg) is the atmospheric layer closest to the planet and contains the largest percentage of the mass of the total atmosphere. It is characterized by the density of its air and an average vertical temperature change of 6 degrees Celsius (C) per kilometer.
Temperature and water vapor content in the troposphere decrease rapidly with altitude. Water vapor plays a major role in regulating air temperature because it absorbs solar energy and thermal radiation from the planet's surface. The troposphere contains 99 % of the water vapor in the atmosphere. Water vapor concentrations vary with latitudinal position. They are greatest above the tropics, where they may be as high as 3 %, and decrease toward the polar regions.
All weather (23k jpeg) phenomena occur within the troposphere, although turbulence may extend into the lower portion of the stratosphere. Troposphere means "region of mixing" and is so named because of vigorous convective air currents within the layer.
The upper boundary (18k jpeg) of the layer ranges in height from 8 km in high latitudes, to 18 km above the equator. Its height also varies with the seasons; highest in the summer and lowest in the winter. A narrow zone called the tropopause separates the troposphere from the next highest layer called the stratosphere. Air temperature within the tropopause remains constant with increasing altitude.
The stratosphere (22k jpeg) is the second major strata of air in the atmosphere. It resides between 10 and 50 km above the planet's surface. The air temperature in the stratosphere remains relatively constant up to an altitude of 25 km. Then it increases gradually to 200-220 degrees Kelvin (K) at the lower boundary of the stratopause (~50 km), which is marked by a decrease in temperature. Because the air temperature in the stratosphere increases with altitude, it does not cause convection and has a stabilizing effect on atmospheric conditions in the region. Ozone plays the major role in regulating the thermal regime of the stratosphere, as water vapor content within the layer is very low. Temperature increases with ozone concentration. Solar energy is converted to kinetic energy when ozone molecules absorb ultraviolet radiation, resulting in heating of the stratosphere.
The ozone layer (27k jpeg) is located at an altitude between 20-30 km. Approximately 90 % of the ozone in the atmosphere resides in the stratosphere. Ozone concentration in the this region is about 10 parts per million by volume as compared to approximately 0.04 parts per million by volume in the troposphere. Ozone absorbs the bulk of solar ultraviolet radiation in wavelengths from 290 nm - 320 nm. These wavelengths are harmful to life because they can be absorbed by the nucleic acid in cells. Increased penetration of ultraviolet radiation to the planet's surface would damage plant life and have harmful environmental consequences. Appreciably large amounts of solar ultraviolet radiation would result in a host of biological effects, such as a dramatic increase in cancers.
Meteorological conditions strongly affect the distribution of ozone. Most ozone production and destruction occurs in the tropical upper stratosphere, where the largest amounts of ultraviolet radiation are present. Dissociation takes place in lower regions of the stratosphere and occurs at higher latitudes than does production.
The mesosphere, (36k jpeg) a layer extending from approximately 50 km to 80 km, is characterized by decreasing temperatures, which reach 190-180 K at an altitude of 80 km. In this region, concentrations of ozone and water vapor are negligible. Hence the temperature is lower than that of the troposphere or stratosphere. With increasing distance from Earth's surface the chemical composition of air becomes strongly dependent on altitude and the atmosphere becomes enriched with lighter gases. At very high altitudes, the residual gases begin to stratify according to molecular mass, because of gravitational separation.
The thermosphere (39k jpeg) is located above the mesosphere and is separated from it by the mesopause transition layer. The temperature in the thermosphere generally increases with altitude up to 1000-1500 K. This increase in temperature is due to the absorption of intense solar radiation by the limited amount of remaining molecular oxygen. At an altitude of 100-200 km, the major atmospheric components are still nitrogen and oxygen. At this extreme altitude gas molecules are widely separated.
The exosphere (41k jpeg) is the most distant atmospheric region from Earth's surface. The upper boundary of the layer extends to heights of perhaps 960 to 1000 km and is relatively undefined. The exosphere is a transitional zone between Earth's atmosphere and interplanetary space.
The atmosphere we breathe is a relatively stable mixture of several hundred types of gases from different origins. This gaseous envelope surrounds the planet and revolves with it. It has a mass of about 5.15 x 10E15 tons held to the planet by gravitational attraction. The proportions of gases, excluding water vapor, are nearly uniform up to approximately 80 kilometers (km) above Earth's surface. The major components of this region, by volume, are oxygen (21%), nitrogen (78%), and argon (0.93%). Small amounts of other gases are also present. These remaining trace gases exist in such small quantities that they are measured in terms of a mixing ratio. This ratio is defined as the number of molecules of the trace gas divided by the total number of molecules present in the volume sampled. For example, O3, CO2, and chlorofluorocarbons (CFCs) are measured in parts per million by volume (ppmv), parts per billion by volume (ppbv) or parts per trillion by volume (pptv).
Atmospheric temperature and chemistry are believed to be controlled by the trace gases. There is increasing evidence that the percentages of environmentally significant trace gases are changing because of both natural and human factors. Examples of man-made gases are the chlorofluorocarbons CFC-11 and CFC-12 and halons. Carbon dioxide, nitrous oxide, and methane (CH4) are produced by the burning of fossil fuels, expelled from living and dead biomass, and released by the metabolic processes of microorganisms in the soil, wetlands, and oceans of our planet.
Ozone (26k jpeg) was first discovered in 1839 by German scientist Christian Friedrich Schonbein. It is a pale blue, relatively unstable molecule made up of three oxygen atoms. The ozone molecule is angular, polar, and diamagnetic. Both oxygen bond lengths (1.28 angstroms) are identical. It is formed from molecular oxygen (O2) by ultraviolet and extreme ultraviolet photolysis followed by recombination of atomic oxygen (O) with O2.
It may also be formed by passing an electrical discharge through gaseous oxygen. It is characterized by a unique odor that is often noticed during electrical storms and in the vicinity of electrical equipment. In fact, the term ozone is derived from the Greek word ozein which means "to smell." The density of ozone is about 2.5 times that of O2. At -112 degrees C it condenses to a deep blue liquid. It is a powerful oxidizing agent and, as a concentrated gas or a liquid, is highly explosive.
Excess oxygen atoms, also known as free radicals, oxidize materials that they contact and are associated with the aging process
Depending on where ozone resides, it can protect or harm life on Earth. When it is close to the planet's surface, in the air we breathe, ozone is a harmful pollutant that causes damage to lung tissue and plants, and is considered to be "bad ozone." It is a powerful photochemical oxidant that damages rubber, plastic, and all plant and animal life. It also reacts with hydrocarbons from automobile exhaust and evaporated gasoline to form secondary organic pollutants such as aldehydes and ketones. The peroxyacyl nitrates are especially damaging photochemical oxidants that are very irritating to the eyes and throat.
Ozone pollution originating in urban areas can extend into surrounding rural and forested areas that are hundreds of kilometers downwind. Episodes of elevated ozone concentrations are associated with warm, slow moving high pressure systems and contain between 30 and 50 parts per billion by volume. Concentrations 3 to 8 times greater than natural background levels have been observed. During the summer heat wave of 1988, record ozone concentrations were recorded in the United States. Even Acadia National Park in Maine, and the Shenandoah mountains of Virginia, were affected by dangerous levels of ozone pollution. These rural areas are far removed from industrial regions and polluted cities. The ozone pollution recorded in Acadia most likely originated in New York City. That in Virginia may have migrated from refineries on the Gulf Coast.
Photochemical oxidants are the most significant cause of agricultural loss in the United States. Their damaging effects on vegetation and crops have been confirmed in the eastern United States, adjacent areas in Canada, and much of Europe. Ozone alone, or in combination with sulfur dioxide (SO2) and nitrogen dioxide (NO2), accounts for 90% of the annual crop losses in the U.S. that are caused by air pollution.
Most ozone is concentrated in the stratosphere, (27k jpeg) at about 25 km in altitude, and is considered to be "good ozone." In this region, ozone acts as a shield to protect Earth's surface by absorbing harmful ultraviolet radiation. Without this shield, we would be more susceptible to skin cancer, cataracts, and impaired immune systems. A 1 % decrease in total column ozone causes the amount of transmitted UV radiation, in the spectral region that damages deoxyribonucleic acid (DNA), to increase by about 2 %. Although good ozone only represents a tiny fraction of the atmosphere, it is crucial for life on Earth.
The proportion of good and bad ozone in the atmosphere depends on the balance between processes that create ozone and those that destroy it. An upset in this balance can have serious consequences for life on Earth, and scientists are finding evidence that the balance has changed. Concentrations within the protective ozone shield are decreasing, while levels in the air we breathe are increasing.
Ozone amounts in the stratosphere are small, rarely exceeding 10 parts per million by volume. Ozone is measured in Dobson Units. (40k jpeg) One Dobson Unit (DU) corresponds to 2.69 x 10E16 molecules per square centimeter, which is equivalent to the amount of gas in one square centimeter at 1 atmosphere of pressure. Average ozone levels are 300 DU, which would be equivalent to a layer three millimeters thick if compressed to the planet's surface. Levels may range from less than 100 DU to over 500 DU globally.
Stratospheric ozone is created (1 MB Quicktime)and destroyed (1 MB Quicktime) primarily by ultraviolet radiation. The air in the stratosphere is bombarded continuously with ultraviolet radiation from the Sun. When high energy ultraviolet rays strike molecules of ordinary oxygen (O2), they split the molecule into two single oxygen atoms. The free oxygen atoms can then combine with oxygen molecules (O2) to form ozone (O3) molecules.
O2 + UV light -> 2 O
O + O2 + M -> O3 + M (where M indicates conservation of
energy and momentum)
The same characteristic of ozone that makes it so valuable, its ability to absorb a range of ultraviolet radiation, also causes its destruction. When an ozone molecule is exposed to ultraviolet energy it may break back into O2 and O. During dissociation the atomic and molecular oxygens gain kinetic energy, which produces heat and causes an increase in atmospheric temperature.
Ozone production is driven by UV radiation of wavelengths less than 240 nm. Ozone dissociation typically produces atomic oxygen that is stable when exposed to longer wavelengths, up to 320 nm, and shorter wavelenghts of 400 to 700 nm. Longer wavelength photons penetrate deeper into the atmosphere, creating regions of ozone production and destruction. When an ozone molecule absorbs even low energy ultraviolet, it splits into an ordinary oxygen molecule and a free oxygen atom.
Over Earth's lifetime, natural processes have regulated the balance of ozone in the stratosphere. Scientists are finding that ozone levels change periodically as part of regular natural cycles such as seasons, periods of solar activity, and changes in wind direction. Concentrations are also affected by isolated events that inject materials into the stratosphere, such as volcanic eruptions.
Polar regions reflect the greatest changes in ozone concentrations, especially the South Pole. The topography of Antarctica is such that a stagnant whirpool of extremely cold stratospheric air forms over the region during the long polar night. The air stays within this polar vortex all winter, becoming cold enough to allow the formation of polar stratospheric clouds.
Polar stratospheric clouds speed up the natural process of ozone destruction by providing ice crystal surfaces on which the destructive reactions take place. After the long polar winter, ozone within this extremely cold vortex is very vulnerable to the arrival of sunlight. As spring arrives, major ozone losses occur. In the southern hemisphere, the area of most severe ozone depletion is localized above Antarctica and is generally referred to as the ozone hole. The hole appears in the southern spring, following the continent's coldest season and polar night.
Ozone depletion over the Arctic is not as well defined as in Antarctica. The rugged topography results in an air circulation pattern that is quite different from that of the South Pole, but expeditions have shown that the atmospheric chemistry of the two polar regions is very similar. In the Northern Hemisphere, the polar vortex is not as strong. It can break up and reform several times during the course of winter. One air mass after another enters the polar darkness and soon emerges back into low sunshine. Thus, a bit of ozone is lost from each parcel of air, rather than a large amount from one parcel as in the southern hemisphere.
The end result is that we are losing ozone in both hemispheres. (26k jpeg) Ozone levels in the atmosphere have been monitored from the ground since the 1950s and by satellite since the 1970s. Regional total ozone levels measured from satellites over Antarctica have decreased 30-50% since their monitoring began.
Since ozone is created and destroyed by solar UV radiation, there is some correlation of ozone concentration with 11-year sunspot cycles. Sunspots emit high levels of electromagnetic radiation. The increased UV radiation contributes to ozone production. Sunspot variations only account for 2 to 4 % of the total variation in ozone concentrations. Natural cycles in ozone variation are also associated with the quasi-biennial oscillation in which tropical winds switch from easterly to westerly every 26 months. This cyclic change in wind direction accounts for approximately 3 % of the natural variation in ozone concentration.
|
I promise to answer your message -- click here to send me a personal message
|
SUBSCRIBE: The Wednesday Letter is a free electronic monthly newsletter written and published by Karl Loren. You can view more than 50 back issues of this publication by clicking here. The Wednesday Letter subscription list is maintained on a secure server, no name is ever given or sold to anyone, and it is never used except for this Newsletter. It is automatically published on the Tuesday night just before the first Wednesday of every month. You can subscribe to this free monthly electronic letter by entering your eMail address and name below. You will then automatically receive a request for confirmation, sent to whatever address you have entered. If you do NOT receive this confirmation request, then you will not be subscribed. There may have been an error with your address and you should resubmit. The letter is never sent twice to the same address -- so you do not have to worry about a duplicate subscription. When you receive this confirmation request you must reply to it, or your subscription will not become active. No one can subscribe your name, and address, without you being notified, and if you get an unwanted notice of subscription you only need to DO NOTHING and the subscription will NOT be active.
REMOVAL: You can remove yourself from the subscription list in several different ways. Click here to read about this entire newsletter system. Every edition of The Wednesday Letter is delivered to your address with YOUR name and address in view on the letter, with a link that allows you to remove THAT name from the subscription list. If you try to send this removal message from an address different from the one you used to send in your original confirmation, then you will get a warning notice first, sent to the subscription address, asking you to confirm that you want to be removed from the list -- by replying to THAT request for confirmation, you will then be automatically removed. Thus, no one else can unsubscribe you, from some other computer, without your knowledge. But, if you send in the unsubscribe notice from the same machine used to receive the Letter, then the removal from the subscription list is automatic.
Personal Message: When you send a personal message to Karl Loren, you will receive a personal reply as per his instructions. Karl pledges that every personal message will get a personal answer. When you provide your mail address, we will send you free information including our free catalog and a cassette tape lecture by Karl Loren about heart disease, no charge, by mail, even if outside the US. You can select particular information you would like to receive, along with the free cassette tape and catalog.
You can reach Vibrant Life in many ways, including by mail to Vibrant Life, 2808 N. Naomi St., Burbank, CA 91504. Within the US and Canada, use the toll free number: (800) 523-4521, the local number: (818) 558-1799, the FAX: (818) 558-7299, eMail to kimberly@oralchelation.com or any one of the hundreds of message forms throughout the 50 web sites. Vibrant Life normally ships the same day we get an order. There are message forms on each of the 100,000+ pages on this and other sites where you can communicate with Vibrant Life. Check out our companion site, at: http://www.oralchelation.net where Karl's 2000 page book is published. Karl Loren is the author and webmaster for this BOOK, as well as for another web site about ORAL CHELATION. His personal philosophical articles are at PHILOSOPHY.
Copyright © April 25, 2008 2:38 AM by Karl Loren on behalf of Vibrant Life, ALL RIGHTS RESERVED. Permission is granted for non-commercial downloading, copying, distribution or redistribution on two conditions: One, that some form of copyright notice is included in every copy distributed or copied, showing the copyright belonging to Vibrant Life, Burbank, CA, at www.oralchelation.com . The second condition is that the material is not to be used for any purpose contrary to the purposes and objectives of this site. This permission does not extend to materials on this site which are copyrighted by others.
