Why is there an ozone hole near/at the South Pole?
149315
This answer can be simple, or it can be more complicated.\n\nThe simple answer is that during the polar winters (both the North AND the South Poles, actually although it is worse at the South Pole because it is colder there), there is not enough sunlight to make ozone, so stratospheric ozone decreases naturally. \n\nThe chemical reactions that do this are called the Chapman reactions:\n\nO2 + hv -> O + O(1)\nO + O2 -> O3 (2)\n\nO is monoatomic oxygen, O2 is the oxygen molecule and O3 is ozone. The term hv is the energy from ultraviolet rays from sunlight. (1/v = wavelength < ~ 240 nm \n\nAlthough the UV radiation splits the ozone molecule, ozone can reform through the following reactions resulting in no net loss of ozone: \n\nO3 + hv -> O2 + O (3)\nO + O2 -> O3 (2) as above\n\nOzone is also destroyed by the following reaction: \nO + O3-> O2 + O2 (4)\n\nOne would expect ozone to decrease when there was no sunlight from (4).  \n\nHowever, we have observed that even more ozone than these Chapman reactions would predict was being lost during the polar winters. And this is probably because of a reaction involve a man-made chemical, CFCs or chlorinated fluorocarbons, which are not being phased out by international agreement. This process works best when it is very cold and there is no sunlight. \n\nThere are much more sophisticated explanations. Here is a more complicated explanation I wrote:\n\nThe conditions that create regions of depleted ozone are enhanced during the winter months, when there are much lower temperatures. However, the conditions for ozone depletion peak in the springtime, at the end of the winter. This is somewhat unfortunate, because at that time the ozone holes then break up, and neighboring areas are subjected to a decrease in ozone protection at a time when ultraviolet radiation is greater, in the late spring and early summer. \n\nThe reaction that depletes ozone is apparently greatest on the surface of what some had thought were ice crystals in the stratosphere that form during the winter months. However , recent theories are that in fact these are not ice crystals, but crystals of nitric acid trihydrate ("NAT"), HNO3.3(H2O). Antarctica is much colder than the arctic, because it is not only a large land mass but also is the continent with the greatest average elevation, both contributing to the severity of its winter weather. This creates much colder temperatures in the entire air column, including the stratosphere (temperatures approach -80C, or -112 F), so there are more frozen NAT crystals and more ozone depletion.\n\nIt is also interesting that the reaction that destroys the ozone needs ultraviolet radiation to proceed, and this goes on during the time of the year when there is minimal sun. However, it should be noted that this peaks during the spring when the sun is returning, and the process occurs high in the stratosphere, so more light is present than it is at ground level, especially better refracted wavelengths like those in the ultraviolet region.
379504
Solar heating is more pronounced at the equator where rays are vertical and closely spaced. At higher latitudes there is less heating, rays less dense, more oblique. The tilt of the earth's axis introduces a further, seasonal variability. Seasons occur in opposite months of the year in opposite hemispheres. Winter in the northern hemisphere is simultaneous with Summer in the southern hemisphere.\n\n--assume you are looking at earth broadside, equatorial view, for the following, throughout (no polar views)--\n\nEQUATORIAL HEATING\nAir masses at the equator have an eastward inertia. As they are heated, these masses expand and rise. Keep the inertia in mind as you read all of the following.\n\nConsidering first the northern hemisphere, as this high equatorial rising air pushes to the north it has a higher speed eastward relative to the earth's surface. This is because the eastward inertia of a mass of air varies at different latitudes. \n\nAir at the equator is moving faster, along with the rotating earth, than is air at higher latitudes. Identical for both hemispheres, north and south: Air at higher latitudes has less eastward speed.\n\nOn the equatorial surface cooler air moves in from the northeast and the southeast. This air is moving west because it has less eastwards inertia as it approaches the equator, from higher latitude. These are the Trade Winds, blowing east to west on both sides of the equator.\n\n\nNORTHERN HEMISPHERE\nAs the hot, rising air from the equator cools at higher latitudes and sinks in the latitude 30's region, some moves further north and eastwards, some moves further south and westwards.\n\nSOUTHERN HEMISPHERE\nAs the hot, rising air from the equator cools at higher latitudes and sinks in the latitude 30's region, some moves further south and eastwards, some moves further north and westwards.\n\nThe northern and southern hemispheres are mirror opposites.\nWe see that these movements are caused by the heating effect of the sun. \n\nWe see that in the northern hemisphere cold air moving south veers to the left (westward) and warm air moving north veers to the right (eastward). The accounts for the clockwise highs and counterclockwise lows.\n\nIn the southern hemisphere, cold air moving north veers to the west and warm air moving south veers to the east. The net effect here is counterclockwise highs and clockwise lows.\n\nIf one has a hard time picturing this, just remember, highs and lows spin in opposite directions. Lows are clockwise in the southern hemisphere and counterclockwise in the northern hemisphere.\n\nWinds blow from high to low pressure. The denser the isobars (lines of equal pressure) on the weather map, the greater the wind speed. Highs are the directors, lows are the actors.* This means the hurricane will have a fit wherever it is guided by high pressure.\n\n*Rodewald, German meteorologist\n\nThis explanation says little about weather from 30 degee latitudes further north or south. To describe the entire globe in detail is impractical here. The principal forces involved in your question have been described.\n\nFor a more detailed explanation, I recommend OUR ATMOSPHERE, by Theo Loebsack, A Mentor Book\n\nYes, every time I think about all this, my head spins. Try to think very carefully and hard about it occasionally and it will become somewhat clearer.\n\nThe important thing to remember is what is happening on the ground where most of us live and work. Since LOWs are the big actors, remember they are counterclockwise in the northern hemisphere and clockwise in the southern hemisphere.\n\nA very good exercise, especially for sea goers, is to picture the wind directions you would experience from various compass points surrounding a ferocious low. Do this remembering which hemisphere you are in, north or south. Understanding that could mean survival. You want to avoid everything, to the extent possible, but especially the eye wall. The innermost winds are the most horrific, w
1065551
The ozone layer is thining through incresed pollutio by planes brought about by a peak in flyers, green house emissions, increased industrial pollution, forest degradation. all these allow more UV light penetration into earth and will continue to increase unless we stop polluting the environement.:(
733895
From Glenn Kawesch:\nThe layer of atmosphere that lies about 15 to 50 kilometres above the Earth's surface. In the stratosphere, the temperature rises with increasing height, which is the opposite of the situation in the lower atmosphere. Ozone occurs in minute quantities throughout the full depth of the atmosphere, but its concentration peaks within the stratosphere at an altitude of about 35 kilometres. This is referred to as the ozone layer. There is little up-and-down air movement in the stratosphere, so the ozone layer stays in position.\n\nGlenn Kawesch
387707
Temperature decreases w/ height as you move up through the troposphere b/c of a decrease in air pressure.\n\nAir pressure steadily declines as you move up b/c there is less gravity. Since gravity acts on everything that has mass, including air, it holds most of the earth's air close to the ground. Air acts as an insulator or blanket, absorbing long wave radiation reradiated from the earth. When you move upward away from the surface, the air thins out. There is less air to hold heat.\n\nHowever, once you leave the troposphere, you enter the stratosphere. Here the temps steadily increase due to the presence of the ozone layer. The ozone traps heat.\n\nAs you move away from the stratosphere you will enter the mesosphere where temps decrease again due to less air & movement away from the ozone layer.\n\nAs you go even higher & enter the Thermosphere, the temps increase again b/c solar radiation is so intense that the few air particles that are present are super heated. The chances of being burned are slight to none b/c the air particles are few & far between. After all that is what is holding the actual heat.
115204
This is complex issue without consensus in the scientific world.  Getting away from the politically correct interpretations is the following:\n\nFor years, the ozone depletion-impact crowd was worrying about the effects surface ultraviolet radiation would have on the Antarctic ecosystem—though, as we’ve said before, the Antarctica ecosystem, except for a few penguins, consists entirely of scientists studying the ozone hole.\nThis year (and it has happened before), the National Aeronautics and Space Administration (NASA) reported the infamous hole (which is not really a hole at all but a reduction in total column ozone) has spread over a populated area: Punta Arenas, Chile. Chilean health officials warned people to remain indoors during the high sun periods as ozone levels there dropped to about 175 Dobson Units (a measure of the total amount of ozone in the atmospheric column above any location). Similarly low values were occurring over and surround Antarctica.\nQuickly, David Hofmann, director of the Climate Monitoring and Diagnostics Laboratory of the National Oceanic and Atmospheric Administration (NOAA), countered that though the hole is large, the severity of the ozone depletion within that hole was comparable to ozone levels measured over the past few years.\nThen, the World Meteorological Organization, which measures ozone depletion slightly differently, spun its own ozone yarn, declaring that the end of September’s depletion was the worst on record. But once again, as is unfortunately common with most environmental news, this is much ado about nada.\nFirst, the size, shape, and amount of ozone depletion are significantly affected by the weather. The Antarctic stratosphere was cold this past winter (global warming?), which resulted in more depletion than normal. That minor factoid was buried in the last paragraph of CNN’s coverage of this nonstory.\nAs NOAA’s Hoffman explained, “year-to-year fluctuations in the geographical size of the ozone hole and the timing of the ozone production are believed to be related to meteorological factors such as temperature and winds, rather than further increases in ozone-destroying chemicals in the atmosphere.”\nSecond, if these levels of ultraviolet radiation seen in Punta Arenas were truly harmful, most of the world’s population would be in grave danger. Most of us, on a regular basis, are exposed to solar radiation far more intense than that seen in southern Chile.\nAn index of global ultraviolet light levels, assuming cloud-free and unpolluted skies, was constructed for October 11, the same day as the 175 Dobson Units reading in Punta Arenas. The UV index there of around 9 is much lower than UV levels across more than half of the planet. Most places receive more intense solar rays than Punta Arenas does.\nThird, the expanded ozone hole is short-lived. By November, as Antarctica warms, the vortex of winds that effectively isolate Antarctica from the rest of the planet weakens, and high ozone levels over the rest of the hemisphere quickly fill the so-called hole. That process only serves to highlight the climatological uniqueness of the situation over Antarctica.
337268
The north pole is not on a continent.  It is in the middle of the arctic ocean which has a frozen ice cap.
1064706
Ozone is actually O3, and it can only be naturally created in the stratosphere by incoming ultraviolet light.  The problem with the ozone layer isn't a lack of oxygen -- there's plenty to do the job -- but rather the presence of CFC's that have drifted up there from ground level over the past hundred years or so.  Chlorofluorocarbons, in the presence of ultraviolet light, release free chlorine radicals which attack ozone and reduce it to O2 in a catalyzing reaction; it is calculated that each chlorine radical can reduce around 100,000 ozone molecules before reacting with something else and being removed from the stratosphere.  So the removal of ozone becomes greater than the generation of ozone and you get a thinning (the ozone "hole" over the Antarctic and Arctic regions is a result of winter vortex winds which tend to concentrate atmospheric contaminants (including CFC's) in that area right around the poles, worsening the local damage.)\n\nGenerating ozone at ground level does a lot more harm than good -- you need it about fifteen to twenty kilometers up for it to protect you, and at ground level, because ozone is a powerful oxidizing agent, it can do your body a lot of harm.  Add to that the immense expense of generating enough ozone to do any good -- ozone can be artificially created by running an electrical arc through air (it's that "electrical" smell you get before a lightning storm or if your copy machine has been running a long time)  The energy requirements to produce the ozone and the logistics of getting it up to the statosphere soon enough to do us any good have already been estimated, and let's just say if you thought your taxes are high now, just wait for the price tag on this project, estimated by some in the tens of quadrillions of dollars to be effective.  So basically, if all the nations in the world gave us ALL their money, we could jointly afford to make this project a reality.  Ain't gonna happen, sorry to say.\n\nThe best way to repair the hole in the ozone layer is to eliminate the use of CFC's as refrigerants in favor of more ecologically friendly gases, and allow nature to repair itself.  We're already seeing a gradual decrease in the seasonal size of the ozone hole from the reduction or complete cessation of CFC use by most industrialized nations (some developing nations still use CFC's because they're cheap; we're working on trying to get them to switch as well)  It'll take upwards of 50 years before we really see the benefits of this -- takes that long for ground-level gases to rise to the stratosphere through natural circulation.
80234
Some places that are cold now like antarctica were once in warm places like the equator, so they had vegetation and animals on them. Our theory is that these organic materials produce hydrocarbons. Of course, climate change could also do this without plate tectonics, as well. However, these two processes work togeher.
511642
The poles are not good places for observatories, from a purely geometric point of view. From the north pole, you can see only half the sky, the same half night after night for six months. Then during the summer the sun is in the sky all the time and you can't see anything except the sun.\n\nA similar problem exists at the south pole, except that the seasons are reversed.\n\nFrom the equator you can see the entire sky over the course of a year. On any single night, you can see only some of the sky, but if you wait a year you can see it all.
867358
It's actually a play of words. It's not hot because of low pressure... is low pressure because it's hot.\n\nThe coldness of the north pole has nothing to do with altitude... it's more about the actual amount of energy it receives from the sun during the year. I believe you're mixing up a couple of concepts here.
308119
You have a misconception as to what an ozone layer is.  Ozone is a gas and is found throughout the atmosphere, even at ground level.  The ozone layer is the range in the atmosphere where ozone levels are the highest.  Oxygen O2 is present in the ozone layer as well (as are all other atmospheric gasses).  You should also note that in the ozone layer there isn't actually a whole lot of ozone, just more than there is anywhere else.  I think it's around 5 parts per million; meaning there is 1 molecule of ozone for every 200,000 other molecules.  There isn't a blanket of ozone, it's just an area where ozone is 5-10ppm instead of 1ppm or less.  \n\nWhy does most of it stay where it is?  Ozone is a somewhat unstable molecule and the same mechanism that typically forms ozone also breaks it down.  Simply, O2 gets hit by some photons of the right energy (some kind of UV light) and is split into O and O, one (or both) of those O's bonds to another O2 molecule to form O3, ozone.  Sooner or later, that O3 gets hit by the right energy of UV light and one of the O's break off to form O2 and a spare O which will find another O2 to bond with and repeat the cycle.  A small percent of the ozone does drop into the statosphere (where we live).
236055
The southern hemisphere has the biggest problem with ozone depletion because winter temperatures in the stratosphere create a global vortex that traps elemental chlorine over Antarctica, leading to a seasonal depletion and rebuilding of molecular ozone over the same area - The ozone hole is seasonal, not constant, and observations show it is recovering from its lowest recorded ozone levels. During southern hemisphere winters, the thinned ozone areas surrounding the lower latitudes can cause South America, Australia, New Zealand, and other land areas in those higher southern latitudes to experience excess solar UVA and UVB incidence.
768729
This is an interesting but certainly not simple question. Ozone is formed naturally in the stratosphere as O2 molecules absorb UV light and break down to O radicals. These O radicals then react with O2 molecules and collide with another third body to remove excess energy to form O3 molecule.\n\nO2 + hv → 2 O\nO + O2 +M → O3 + M\n\nThese O3 molecules in the stratosphere is considered as our friend because they absorb most of the harmful UV radiation so that we will not be exposed to that. \n\nMore and more studies have shown that our stratospheric ozone is decreasing. This is due to the CFCs that we used long time ago. These CFCs was used heavily long time ago because of its high vapor pressure property. For example, it can be used as fire extinguishants, propellants, and solvents. One problem about these molecules is that they are very non-reactive in the lower atmosphere. As a result, they accumulate in the atmosphere and until they diffuse to the upper atmosphere, where the strong UV can break them down. As these CFCs react with strong UV and form Cl radicals, these Cl radicals undergo a "chain reaction" to destroy our ozone. As you may imagine from the name, each Cl radicals can effectively destroy many ozone molecules before it reacts with something else and be removed. So, only a very small amount is enough to destroy lots of ozone. CFCs have been banned long time ago, but because of its non-reactive property, the ozone hole problem that we are having today is caused by yesterday's CFCs.\n\nOzone in the lower troposphere, on the other hand, is considered as pollutants. It is because these ozone can react with many hydrocarbon in the presence of sunlight to generate smog (which is also called photochemical smog because they are generated in the presence of solar radiation). These smog not only reduce our visibility, they also irritate our respiratory systems. High concentration of ozone can also cause lots of damage to vegetation.\n\nThese lower tropospheric ozone is formed mostly due to reaction of NOx (NO and NO2) with sunlight in the presence of some hydrocarbons. As you may know, the vehicle emission contains lots of NOx, which is one of the reason for causing the tropospheric ozone.
10249
actually, this is one problem that has actually been helped by government.\n\nan international agreement known as the montreal protocol signed in 1988 has restricted the use of ozone depleting chemicals like chlorofluorocarbons, methyl chloroform, methyl bromide and the like.  atmospheric monitoring has shown that the levels of these chemicals in the atmosphere has started to turn over and decline.\n\naccording to the NOAA report on ozone depletion published in 2002, "Chemistry-climate models predict that springtime Antarctic ozone levels will be increasing by 2010 because of projected decreases of halogens in the stratosphere.  A return to pre-1980 total column ozone amounts in the Antarctic is expected by the middle of this century."\n\nso, in other words, we only have to keep doing the right thing and not using the chemicals which we know deplete the ozone, and the earth will heal itself by 2050.  cool eh!
862529
Ozone layer had undergone massive depletion due to natural and man-made causes. It had areas greatly decreased that made it to the point that there is already a "hole" or there is a certain area that no longer contain the ozone layer.\n\nThere are various factors  influencing  the ozone concentrations: >>Stratospheric sulfate aerosols mainly from  large explosive volcanoes greatly affect the ozone layers.\n>>Stratospheric winds  which bring about changes of the tropical winds in the lower stratosphere move ozone from one area to another.\n>>Greenhouse gases which might heat the planet and alter weather patterns affecting  the magnitude of the stratospheric winds.\n>>Sunspot cycle which is largely affected by unusual solar activity, solar storms and large solar flares which highly affect the ozone creation by solar UV radiation.\n>>Stratospheric chlorine, coming mostly from man-made halocarbons.\n\nWith all factors affecting the ozone creation, and movements and all that supports its depletion, ozone layer had lowered its  amount or its concentration which can cause the risk of harmful ultraviolet exposures. In simple term, the ozone layer had undergone thinning of its layer which some area already resulted to have holes. Anything that had thinned severely can breakdown anytime - that also applies to the ozone layer.♥
759009
Don't know for sure, but at the rate global warming is going we're all going to find out!\n\nScientists have speculated that there are life-forms that have not been in contact with the surface  for 15 million years on the bottom of Lake Vostok. The Earth's heat and the pressure/insulation of miles of ice above it keep the Lake Ontario sized body of water from freezing, like the oceans on Europa. No one really knows what is down there because drilling down with current technology would contaminate the lake with surface microbes and change whatever ecology is down there before people can study it.\n\nhttp://www.bbc.co.uk/science/horizon/2000/vostok.shtml\n\nMy guess is just a whole lot of very durable microbes, although some truly strange higher life could be down there if there are hydrothermal vents that would make regular vents seem normal.