The hole is Antarctica occurs in the spring (September to December). It begins with this overall ozone thinning, but it is assisted by the presence of polar stratospheric clouds (PS clouds). During the extreme cold of winter, with no sun for six months, polar winds create a vortex which traps and chills the air; the temperature is below -80 Celsius. The ice in these PS clouds provides surfaces for the chemical reactions that destroy the ozone. This needs light to kick-start the reactions.
In spring the sun rises above the horizon and provides energy which starts the photochemical reactions. The clouds melt and the trapped compounds (chlorine and chlorine monoxide from the CFCs) are released. Ozone in the lower stratosphere is destroyed and the ozone hole appears.
By the end of spring warmer December temperatures break up the vortex and destroy the PS clouds. Sunlight starts creating ozone again and the hole begins to repair.
(A similar hole in the Arctic [but smaller because of warmer temperatures] occurs during spring.)
The "hole" over each pole only occurs during winter months because the issue has to do with a lack of sunlight, and not really an issue with CFC's. CFC's are possibly adding to the issue, but the issue itself has been there for hundreds of years.
Ozone is constantly decaying into oxygen. The sun is needed to break down oxygen into ozone. When the sun disappears each winter, there is no new ozone. Thus we have an thinning. This is also why the "hole" disappears within a few weeks of the sun's return.
CFC's are much heavier than air, so significant amounts of this chemical getting high enough into our atmosphere to make a noticeable issue is difficult to understand.
In the atmosphere.See "Why is an ozone hole formed only above Antarctica and not over developed countries that emit a lot of CFCs?"
Ozone hole is formed only at poles. It is because the CFC's are carried by westerly winds towards the poles.
So far, Antarctica, and the tip of South America.
Not all countries above the Brandt line are developed and not all countries below are underdeveloped. For example, much of Central Asia is developing, but they are above the Brandt Line and several countries south of the line like Singapore are developed.
Developed countries are countries that are labeled as "First World Nations." These are countries that are generally rich (per capita and government wise), have good treatment of its citizens (plenty of freedoms for example), is not corrupt, etc. Some examples of developed countries are Norway, Australia, the Netherlands, the United States, New Zealand, Canada, and Ireland (which are the most developed nations). Developing countries are currently in the process of becoming developed (inheriting all the traits listed above and more). Some examples of developing countries include China, Vietnam, and Iraq.
The ozone layer dissolves above Antarctica. It is because of cold temperature there.
Much of Antarctica is more than 10,560 feet above sea level.
Antarctica is land. It's a continent.
According to the Human Development Index, a development scale of 0-1, there are 35 countries and territories/dependencies with a development level of 0.9 or above, meaning "highly developed". The total population (as of 7/1/2008) of the countries in that category is 978,186,023 or 14.6% of world population (6,706,992,932). This means that 85.4% (5,727,771,964) of the world's population lives in developing countries.
The Southern Ocean surrounds the continent of Antarctica.
above Antarctica
Cold