What is the ozone layer?

Answer 1

The Ozone Layer

"The ozone layer" refers to the ozone within stratosphere, where over 90% of the earth's ozone resides. Ozone is an irritating, corrosive, colorless gas with a smell something like burning electrical wiring. In fact, ozone is easily produced by any high-voltage electrical arc (spark plugs, Van de Graaff generators, Tesla coils, arc welders). Each molecule of ozone has three oxygen atoms and is produced when oxygen molecules (O2) are broken up by energetic electrons or high energy radiation.
The ozone layer absorbs 97-99% of the sun's high frequency ultraviolet light , light which is potentially damaging to life on earth. Every 1% decrease in the earths ozone shield is projected to increases the amount of UV light exposure to the lower atmosphere by 2%. Because this would cause more ozone to form in the lower atmosphere, it is uncertain how much of UV light would actually reach the earths surface. Recent UV measurements from around the northern hemisphere indicate small UV increases in rural areas and almost no increase in areas near large cities.

Units used to measure ozone concentration
When describing the amount or concentration of gas, scientists resort to several different units:
Dobsin unit (DU)- the principle unit for measuring ozone concentration. One DU is about twenty-seven million molecules per square centimeter ( the palm of your hand covers an area of rougly a hundred square centimeters). The ozone concentration over the US is about 300 DU and the antarctic hole during the late spring can drop to 117 DU.
Mixing ratios: within a specified volume, it is a fraction of the number of molecules of a particular gas divided by the total number of molecules in that given space. Terms of usually abreviated, like ppmv for parts-per-million or ppbv which is parts-per-billion . For example the concentration of HCl at 3 km is said to be about 0.1 ppbv; this means that if you selected a volume of air that contained 10 billion molecules of air, one of those molecules would be an HCl molecule.
Factors influencing Ozone concentrations
Stratospheric sulfate aerosols: large explosive volcanoes are able to place a significant amount of aerosols into the lower stratosphere, as well as some chlorine. Because more than 90% of a volcanic plume is water vapor most of the other compounds, including volcanic chlorine, get ''rained-out'' of the stratosphere. The effects of a large volcano on global weather are significant, which in turn can affect localized weather patterns such as the antarctic ozone hole. Many observations have linked the 1991 Mt. Pinatubo eruption to a 20% increase in the ozone hole that following spring[Solomon et al. 1993]) . The effects of a large volcanic eruption on total global ozone are more modest (less than 3%) and last no more than 2-3 years.
Stratospheric winds: every 26 months the tropical winds in the lower stratophere change from easterly to westerly and then back again, an event called the Quasi-biennial Ocillation (QBO). The QBO causes ozone values at a particular latitude to expand and contract roughly 3%. Since stratospheric winds move ozone, not destroy it, the loss of one latitude is the gain of another and globally the effects cancel out.

Answer 2

It is a layer of air in the stratosphere that has a higher than normal (as compared with the rest of the atmosphere) level of ozone. Ozone is a molecule composed of 3 oxygen atoms.

The ozone layer is important because it absorbs much of the most dangerous ultraviolet radiation coming to Earth from the sun. UV-radiation is what causes sunburns and can lead to cancer.

There is also a lot of environmental concern about the "hole" in the ozone layer that develops over Antarctica during the spring, but that is a big topic that probably warrants a separate question if you want to know more about it.

Answer 3

The ozone layer, or ozonosphere layer (very rarely used term), is the part of the Earth's atmosphere which contains relatively high concentrations of ozone (O3). "Relatively high" means a few parts per million—much higher than the concentrations in the lower atmosphere but still small compared to the main components of the atmosphere. It is mainly located in the lower portion of the stratosphere from approximately 15 km to 35 km above Earth's surface, though the thickness varies seasonally and geographically.[1] The ozone layer was discovered in 1913 by the French physicists Charles Fabry and Henri Buisson. Its properties were explored in detail by the British meteorologist G. M. B. Dobson, who developed a simple spectrophotometer that could be used to measure stratospheric ozone from the ground. Between 1928 and 1958 Dobson established a worldwide network of ozone monitoring stations which continues to operate today. The "Dobson unit", a convenient measure of the total amount of ozone in a column overhead, is named in his honor.

Answer 4

The ozone layer is created when the solar winds collide with the earth's magnetic field. The beta particles are attracted to the north pole and make it negative . The alfa particles are attracted to the south pole and make it positive. This places a huge charge across the O3 and holds it in place. Not affected by CFC .or other pollutants they just don't go that high.

Answer 5

A layer of ozone gas, which is a form of oxygen. O3 instead of O2. It blocks much ultraviolet radiation. The reduction in UV is necessary for the protection of all life on earth.

Much more here:

http://www.theozonehole.com/