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Ozone Layer

The ozone layer is a crucial layer in the Earth's atmosphere that absorbs and blocks out harmful ultraviolet light that can damage Earth.

19,113 Questions

What are the causes of the hole in the ozone layer?

Briefly:

CFCs and similar man-made gases break down the ozone in the stratosphere allowing in harmful ultraviolet radiation. The ozone hole happens mostly in Antarctica where four months of winter darkness create ideal conditions for the destruction.

Ozone is a protective layer in the upper atmosphere. It is formed, when oxygen molecules absorb short wavelength ultra violet radiations from the sun. Ozone is mostly destroyed by the free radicals in the atmosphere. When compounds like CFCs (chlorofluorocarbons) are released, they are dissociated by sunlight into chloride radicals. These radicals attack ozone, thereby decreasing its concentration. This results in hole in the ozone layer.

The hole in the ozone layer happens because the ozone in the stratosphere is destroyed by chlorine and bromine from halogen atoms. These atoms come from man-made halocarbon refrigerator gases (chlorofluorocarbons [CFCs], freons and halons) which are emitted at ground level but move up into the ozone layer. These gases all contain chlorine and bromine.

Ozone (O3) is formed when ultraviolet (UV) light strikes an oxygen molecule (O2), converting it into two oxygen ions (O). These oxygen ions (O) combine with other oxygen molecules (O2) to form ozone (O3). Later, another oxygen ion (O) will combine with the ozone molecule (O3) to form two oxygen molecules (O2). This is the natural ozone-oxygen cycle of the earth.

The ozone layer prevents the harmful ultraviolet B-waves (UV-B) from reaching the earth. Increased exposure to UV-B is thought to be responsible for increases in skin cancer, eye cataracts and damage to plants and plankton. Because of this the nations of the world in 1989 adopted the Montreal Protocol which bans production of CFCs, halons and other ozone-depleting chemicals.

The ozone hole happens during the spring in Antarctica (Sept to Dec). Polar Stratospheric Clouds (PSCs) form during the all-dark winter. When spring arrives and UV light appears again, crystals of ice and nitric acid in these clouds help to release the chlorine and bromine atoms from the halocarbon gases. These destroy the ozone. (A single chlorine atom can continue destroying ozone for up to two years, reacting with up to 100,000 ozone molecules.)

Another view:Natural issues:

Because the concept of man made pollution doesn't cover all of what we see, another look at the issue is demanded. In the man induced theory, the depletion of ozone is due to release of man-made chemicals such as chlorofluorocarbon (CFC) compounds.

Over time these heavier then air chemicals work their way up into the upper stratosphere. CFC's break apart under UV radiation releasing chlorine atoms that would destroy ozone.

Assuming this man induced theory on the origin of the ozone hole is correct, the area most affected would be the mid-Latitude Northern Hemisphere where the industry and population centers in the U.S., Canada, Europe, India, Asia, Russia, China and Japan exist. This is precisely what is not happening! This area is where the least action occurs.

Instead, we are observing a substantial annual ozone hole in one area only, the Antarctic and then only during times of no sunlight (the polar winter). Once the sun returns, the hole disappears quickly. A substantially smaller hole (NASA calls this the dimple because it is so small) is also known to occur over the world's second cleanest area, the Arctic.

A second issue exists. The sun often generates explosions that produce bursts of high-energy protons. These are called Solar Proton Events. Ozone layer density on Earth can be dramatically affected by SPE's, which can locally decrease ozone content in the stratosphere up to 5%.

Some events that have caused serious dents in our levels of ozone levels can be measured using Nitrate Spike Signatures.

They show us large thinning of our ozone layer occurred prior to the creation of CFC's in September of 1859 and in July 1892.

Thirdly, There is growing evidence that ozone levels at the poles is directly connected to the strength of our magnetic fields. The ever weakening fields are believed to be assisting with the size and strength of the ozone hole. Projections for the hole, if tied to magnetic levels of the planet, are for an increasing hole, despite the banning of CFC's.

It is unfortunate that many confuse ozone depletion (which could be a man induced issue) with this natural event. Please see the related link below for a peer reviewed explanation of the natural event we refer to as the hole in the ozone layer;

Bad gases such as Carbon Dioxide and other fumes harm the Ozone layer. CFC (A fluorocarbon with chlorine; formerly used as a refrigerant and as a propellant in aerosol cans) is also the main problem in which the ozone has become thinner. It has been banned in 1966, but the effects are still slow.

The ozone hole is a natural event that occurs when it is winter at a pole. UV-C is required to replace ozone that is decayed (naturally or otherwise), and in winter at a pole, it gets no UV-C, so the ozone decays to very low levels. It also heals up towards spring, such that there is no ozone hole once UV-C from the Sun arrives.

See "How did the ozone hole occur?"

More information:

The "hole" in the ozone layer is not a hole in any real sense of the word, but a thinning of the amount of ozone in the atmosphere over the Antarctic during the end of the winter. This hole has been naturally occurring for centuries and is due, almost exclusively, to the lack of sunlight over this area during the long winter. A smaller, but similar situation occurs over the Arctic during the end of it's winter months. NASA refers to this thinning area as the dimple due to the small size when compared to the Antarctic's situation. Solar activity is also a known issue for the amount of ozone in our atmosphere. The largest known thinning of that we know of actually occurred in 1859 and is believed to have been caused by solar activity. CFC's are also having some contributory affect on the amount of thinning of the ozone.

Ozone depletion was observed to increase as emissions of halo-carbons increased.

Ozone is a protective layer in the upper atmosphere. It is formed when oxygen molecules absorb short wavelength ultra violet radiations from the sun. Ozone is mostly destroyed by free radicals in the atmosphere.

When compounds like CFCs (chlorofluorocarbons) and other halocarbons are released, they are dissociated by sunlight into chloride radicals. These radicals attack ozone, thereby decreasing its concentration. This results in a thinning of the ozone layer, and in polar regions, a hole.

The holes occur at the poles, and usually in Antarctica because of the extreme cold. During the winter polar stratospheric clouds form which are able to convert gases in the atmosphere into Cl (chlorine) and ClO (chlorine monoxide). When the sun arrives at the end of winter, that is the trigger to begin. This is why the hole is largest in spring.

The ozone hole occurs once a year at each pole. The southern polar hole is larger than the northern polar hole due the fact that the southern pole is much colder than the northern pole. The size of the hole is what is of concern and is caused by chlorofluorocarbons (CFCs) and halogens from human industry.

Ozone decays naturally with time. With the axial tilt that Earth has, once each year (local winter) each pole stops receiving the UV-C that turns some oxygen into ozone. So the ozone starts decaying, and a hole forms. The only ozone the pole gets at this time, diffuses in from areas that are still receiving UV-C. So the ozone would be exceedingly thin at this time. The presence of the polar jet stream prevents the ozone at the poles (during local winter) from being replenished as it is throughout the year otherwise.

Add contaminants to the mix, and the amount of ozone drastically decreases. Water vapor (natural and Man-sourced), chlorine (most commonly Man-sourced, carried by CFCs), and bromine (most commonly natural, but likely some Man-sourced, carried for example in halon) all have shown abilities in depleting ozone.

The concentration of ozone at any point is a balance of incident UV-C from the Sun (both making and destroying ozone), UV-B from the Sun (destroys ozone when absorbed), time, and compounds that can accelerate the decay of ozone.

The southern hole is larger because it is so much colder. It is cold enough to form something known as Polar Stratospheric Clouds (PSCs). These form a deposition site for the radicals in the atmosphere that are responsible for ozone depletion. These radicals can be recycled after use so that one molecule of contaminant (chlorine) is responsible for the destruction of several thousand molecules of ozone.

What can we do to protect the ozone layer?

Since the banning of CFC in industry (Montreal Protocol, 1989), ozone depletion has mostly stopped with some signs that levels are increasing. Scientists believe that ozone will return to its pre-CFC level by about 2050.

Ways to Protect the Ozone Layer:
  1. Minimize high altitude aircraft flights (oxygen reduction and water vapor deposition)
  2. Minimize rocket flights (water vapor deposition)
  3. Encourage growth of plants that produce oxygen, discourage deforestation
  4. Decrease / control releases of high temperature steam / moisture to the atmosphere
  5. Eliminate production and release of known ozone depleting chemicals (such as CFCs and HCFCs) where remotely possible. Subsidize production of safer alternatives where possible.
  6. Establish controls to assure that new compounds to be used in high volume, are surveyed for effect on ozone.

Actions an Individual Can Take (see the link below for more):

  • Ensure technicians repairing your refrigerator or air conditioner recover and recycle the old CFCs so they are not released into the atmosphere.
  • Vehicle air conditioning units should regularly be checked for leaks.
  • Ask about converting your car to a substitute refrigerant if the a/c system needs major repair
  • Help start a refrigerant recovery and recycling program in your area if none already exists.
  • Replace halon fire extinguishers with alternatives (e.g. carbon dioxide or foam).
  • Suggest school activities to increase awareness of the problem and to initiate local action.

Various steps are being taken to avoid the ozone depletion. It includes the ban on ozone depleting chemicals most of them being CFCs.
There are various steps to control ozone depletion. The major of them being reduction of use of CFC's that is chlorofluorocarbons. These compounds are responsible for the depletion of ozone layer.

Does the ozone layer have anything to do with global warming?

No, Global Climate Change has very little to do with the Depletion of the Ozone Layer.

Recent global climate change or global warming is now considered by most climate scientists to be the likely result of increases in man-made greenhouse gas concentrations such as carbon Dioxide (CO2) in the atmosphere. These gases absorb strongly in the Infra red part of the electromagnetic spectrum. This has the effect of trapping heat and raising the temperature of the lower atmosphere.

The depletion of the ozone (O3) layer or 'ozone hole' occurs mainly in the stratosphere, and is due to the catalytic destruction by atomic chlorine and bromine. The main source of these is from the photodissociation of man made chlorofluorocarbon (CFC) compounds.

These effects are usually regarded as distinct phenomena. However there are a number of areas of linkage between ozone depletion and recent global warming.

  • The same CO2 radiative forcing that produces global warming is expected to cool the stratosphere leading to a relative increase in ozone depletion
  • Reduced ozone causes the stratosphere to absorb less solar radiation, thus cooling the stratosphere while warming the troposphere; the resulting colder stratosphere also emits less long-wave radiation downward, thus cooling the troposphere. Overall, the cooling dominates
  • Ozone depleting chemicals are also greenhouse gases.
  • One of the strongest predictions of the greenhouse effect is that the stratosphere will cool, due to less infra red radiation coming up from the surface and greater radiative cooling of the stratosphere due to more CO2.

Ozone is also created at the surface due to photochemical reactions between various man made pollutants, this adds to the greenhouse warming but is nothing to do with the ozone depletion in the stratosphere.

Can you give me a good slogan on ozone layer?

how do u save the ozone layer Save nature,make future!!... How can a slogan substitute for use of brain?

What does the ozone layer do?

Short Answer: The ozone layer protects the DNA of all surface dwelling life, by absorbing UltraViolet-B from our Sun.

More detail

The ozone layer is the product of very short wave Ultraviolet light (UV-B) breaking apart oxygen molecules. When ozone is formed, it serves to block energetic UV (UV-B) that other molecules don't, and acts to moderate day / night temperature swings a little bit.

Ozone absorbs UV-B, which would otherwise damage our DNA, and the DNA of all surface dwellers on Earth (including phytoplankton in the oceans). This absorption of UV-B or more energetic light breaks the ozone down into an oxygen molecule and a single oxygen atom. A few of these fragments reassemble as ozone. But primarily UV-B is required to break apart more oxygen to make replacement ozone.

The ozone layer is like a blanket that shields Earth (not just the living things). It is a "greenhouse gas" that moderates day / night temperature swings, and allows the "heat" of the nitrogen and oxygen at altitude to be radiated away (both up and down).

Diseases that increase as the ozone layer gets thinner...

  • cataracts
  • skin cancer (melanoma)
  • cancer in general
  • malnutrition / starvation (since our food crops are similarly attacked)

In which layer of the atmosphere is ozone found?

It is in the stratosphere, located 8 to 50km above sea level. The ozone layer surrounds the earth, meaning that it's wrapped around earth. The altitude varies with latitude as well, placing the stratosphere and the ozone layer closer to the Earth's surface over the poles.

The highest concentration of ozone is in the lower stratosphere, also called the tropopause, and the ozone here is called the ozone layer. Ozone is also found in the lower atmosphere, also called the troposphere, and the ozone here is one component of smog.

Ozone concentrations vary from near zero at extreme elevations (high in the exosphere), to a maximum (~9 ppm) at the bottom of the stratosphere, to zero again near Earth's surface (the troposphere ends here). So some ozone is found in every layer of the atmosphere (usually less than 1 ppm, except for the stratosphere).

When it is winter at one of the poles, there is no UV-C to make ozone, and since ozone decays with time, an "ozone hole" forms. The size of the hole depends on how many contaminants are present to accelerate the decay of ozone.
Ozone is concentrated at 20-40 km above earth with highest concentration 6-8 parts per million. It is present in the stratosphere of the earth's atmosphere.

What are the sub-layers of the the atmosphere?

From the top down:

exosphere

Lonosphere *

Thermosphere

Mesopause *

Mesosphere

Stratopause *

Stratosphere

Tropopause *

Troposphere

(the ones with stars next to them are sub-layers)

What is your conclusion on ozone depletion?

This is a question with an infinite number of answers, since it calls for personal opinion. I would suggest you review the answers to the questions listed in the related questions section below, and make your own choice.

What layers of the atmosphere contains ozone layers?

The stratospheric region contains ozone layer. It protects us from UV rays.

What type of rain are filtered by the ozone layer?

The rays filtered by the ozone are UV rays. The UV rays are extremely dangerous radiations. These radiations can cause skin cancer to living organisms.

Ultraviolet(UV) rays

What are some ways to stop the hole in the ozone layer?

To stop the ozone hole, curb CFC's. They are the ones that deplete ozone.

The ozone hole can be reduced by:

  • avoiding CFC containing products

There are many ways to stop the ozone hole. Stop Aerosol sprays, stop AC's, stop deodorants, stop CFC's.

CFC's react with ozone and cause a hole in the layer.

What is the term for gases produced by aerosols and manufacturing that destroy the earth's ozone layer?

chlorofluorocarbons (CFCs) "ozone depleting substances" are more generic, since other chlorine- and bromine-containing molecules, which are produced by Man, have been found "up there" too. Note that CFCs are not "produced by aerosols", but were intentionally manufactured for the purposes of refrigerant and propellant. Not too many countries are still making / using CFCs.

What protects life on earth from harmful ultraviolet radiation?

The Ozone Layer acts as a blanket to earth protecting it from the harmful ulraviolet radiations of the sun. the rays can cause a no. of fatal diseases to both animals and plants and can affect the various ecosystems of the earth disturbing its ecological balance.

Ozone (O3) is triatomic molecule comprised of three oxygen atoms; it is our main protection against UV light from the Sun.

Which layer of the atmosphere contain most of the ozone layer?

The lower stratosphere contains a CONCENTRATED amount of ozone. However, all parts of the atmosphere contain SOME ozone.

Is UV radiation filtered out by the ozone layer?

Short answer:

Yes, the ozone layer filters out all the UV-C (the most dangerous ultra-violet radiation) and most of the UV-B. The least dangerous radiation is UV-A, and most of this reaches the surface of the earth.

More detail:

Oxygen and nitrogen are the primary absorbers of UV-C and more energetic light (X-rays, gamma rays from space), and they do this completely by the lower stratosphere. One side effect of their absorption of this light, is they make ozone. This ozone is concentrated here, since it is unstable, and the "ozone layer" is formed. Some recombines into N2O*, which later forms either ozone or more stable NOx (if it encounters water vapor first). Some single oxygen atoms encounter O2 and make ozone directly.

Ozone absorbs UV light shorter than 260 nm or so. This includes UV-B, UV-C and more energetic light. Only ozone in our atmosphere absorbs UV-B, which would otherwise be stopped only by soil, meters depth of water, or the DNA of all surface life on Earth.

Additionally, the natural and Man-made "greenhouse gases" in our atmosphere (carbon dioxide, water vapor, ozone, for examples), serve to allow visible light and UV-A in to Earth's surface, but moderate the transmission of infrared light back to space... keeping Earth a tad bit warmer than it would otherwise be without an atmosphere.

Long wave UV (UV-A) and visible light always gets through the ozone layer. As the ozone layer is thinned, additional energetic UV (UV-B) gets through, which will cause problems down here on the surface.

As UV is absorbed, and used in a reaction O3 + uv light = O + O2 ,

Ozone directly absorbs UV-B and either becomes oxygen, or becomes ozone again, with the light scattered again in random directions.

When UV hits the Ozone (O3) it is 'absorbed,' meaning the energy is used to split the ozone into Oxygen gas (O2) and an Oxygen free radical (O). The remaining energy from the UV light is re-emitted as infra-red (heat).

O3 + UV-B -> O2 + O

The Ozone layer is situated on the upper stratosphere. Ozone (O3) is very unstable gas. Ozone is the only gas in our atmosphere that absorbs UV-B.

Oxygen and nitrogen molecules absorb UV-C and more energetic light, and later recombine in different forms. Oxygen atoms sometimes recombine to form ozone, and this primarily occurs in the lower stratosphere... and forms the ozone layer.

Oxygen and nitrogen protect us from very short wave UV, by absorbing the light and breaking apart.

Similarly, ozone has an extra resonance (than its parent oxygen), and can absorb less energetic UV, stuff that still causes cancer, and ozone breaks apart into oxygen gas and a oxygen atom looking for a place to land.

Infrared radiation such as the sun which is blocked by the ozone layer. Such as why to much time in the sun will give you skin cancer. Also it reminds you of when you go to the dentist, whoever is taking your x-ray never stays in the same room and that is why they put a huge metal pad over you. If they did not, it might give them cancer.

Oxygen and nitrogen absorb UV-C. Some of the "shattered" oxygen forms ozone. The UV-C mostly ends up as both heat, and re-emitted as less energetic light in a random direction.

Ozone absorbs UV-B (and some UV-C). The UV-B mostly ends up as heat, and re-emitted as less energetic light in a random direction. Some of the ozone is destroyed in the process of absorbing UV-C or UV-B, and little of it reforms as ozone.

Since atmospheric gases have very low absorptivity / emissivity at visible and IR wavelengths, they do not contribute to heating the surface of the Earth to any great extent. Ozone does have some limited resonance in the IR range, which is why it is called a greenhouse gas too. But it has very low concentration.

UV- C is filtered out but UV-A and UV-B however are not. UV-B is the radiation which begins oxidization of your skin and UV-A is the rays in which change the pigmentation of your skin togive you a tan, UV-C is the only extremely harmful rays and the ozone layer does in fact block them out.

What good things does the Ozone do?

The ozone in the earth's upper atmosphere uniquely absorbs UV-B from our Sun, which would otherwise directly damage the DNA of all surface life... cataracts, melanoma, mutation, and decreases in crop yields. See "What does the ozone layer do?" link below for more. On one hand, long wave ultraviolet light (UV-A) striking the skin produces natural vitamin D in the body, which helps metabolize calcium into bone tissue. On the other hand, short wave ultraviolet light is ionizing radiation which can produce skin cancer. At ground level, ozone is a respiratory irritant, and can aggrivate the respiratory tract and also asthmatic conditions as the ozone is so reactive, it reacts with substances like mucus membranes in your body. Ground level Ozone is most commonly produced by burning fossil fuels, which release oxides of nitrogen (NOx) and unburned fuel. Sunlight converts them with Oxygen in the air to produce Ozone. Ozone can cause breathing difficulties, headaches, tiredness, and in extreme cases... death. Ozone will do everything that oxygen will do, and some things that it won't. It is a powerful oxidizer and is much more powerful than oxygen alone. There are some adherents to alternative medicine who claim many "cures" using ozone. However, there appear to be legitimate medical uses for ozone; see the Related Link. It purifies water--most of the bottled water you see says "purified by ozonation" on it. They use an air stone (or eductor) to bubble ozone through the water, and the ozone kills any organisms that might be living there. Eductors are today more commonly used to apply ozone to drinking water, since eductors do not provide tiny difficult to clean pores in a drinking water system like diffuser stones do. They also provide the possibility of applying ozone into pressurized systems. Ozone is applied into sewer manholes, where it dissolves grease (along with water vapor) and destroys odors (however briefly). Ozone is applied to municipal water (in some cases), where it will destroy pharmaceuticals, destroy taste and odor, make organic molecules easier for activated cabon to destroy, sterilize the water, and act as a flocculant (agglomeration of contaminant molecules that can settle or filter more easily). In organic synthetic chemistry, ozone is used in as a reagent in ozonolysis reaction that oxidize a carbon double to two aldehydes. This is a very useful reaction but dangerous.

What problems did CFCs cause?

In short they attacked and slowly depleted the ozone layer (however they didn't destroy it fully)

Are UV rays intensified by clouds?

No. I believe UV is scattered in all directions just as the other wavelengths, which means you can get burned even in the "shade". But either wave, UV is no more or less intense after passing through clouds.

Why would a Chevy 350 with an Edelbrock 4 barrel carb not accelerate steadily once you get up to 3K rpm's unless you let off the gas some?

Too much fuel or not enough fuel going in...too large a jet size or incorrect float adjustment. I suspect too much fuel because of the performance carb.

Answerprobably because you were hitting the secondarys to early with to much throttle wich would dump to much fuel in the pots AnswerTypical problem with engines that have had "external" modifications only to improve performance. It's called "over-carburation", and is often the case when a carb that is too big is bolted to an engine not properly prepared to accept it. Headers help, but what you will need to do, is replace your cam with one that matches the capacity of your carburetor, or get a smaller carb. In short, spend more money.

What products and processes give off chemicals that destroy ozone?

Evaporation is a primary issue as is a lack of sunlight. Without sun the hole starts.

Processes would include solar activity. The largest know hole occurred in 1858, during a heavy solar flare.

Some believe, and there is some evidence to show it is possible, that CFC's contribute in some manner to the hole that occurs annually above the Antarctic.

What are the holes in the ozone layer?

The Ozone Hole present in the ozone layer over the antarctic region is not actually a hole. It is the the thinning of the ozone layer below a certain level which is defined as the ozone hole. The formation and depletion of ozone is a natural ongoing process because of which the ozone layer keeps intact in the stratospheric region. However due to the use of CFC's the rate of formation is ozone is lesser than the depletion i.e. the CFC's are depleting more of ozone to make the ozone hole go bigger day by day.

How easily is a hole in the transmission pan fixed and how can you do it?

have someone weld a patch panel on it, or if it is small enough use a product called JB Weld which can be picked up at any autoparts store.