Question

Why ozone hole over antarctica not over continents?

Answer 1

The primary reason in the Southern winter is that the sun doesn’t shine in the Antarctic. The sun is what makes atmospheric ozone.

The secondary reason is that the air flows at the appropriate altitudes are isolated in the Antarctic from the rest of the globe such that the ozone is not replenished from other latitudes.

Answer 2

Answer:

Ozone holes are more apparent in the region of Antarctica. They are formed as a result of an increased concentration of chlorine in the atmosphere. The release of chlorine is mainly from Chlorofluorocarbons (CFCs) which is extensively used as a refrigerant. The CFCs migrate from different layers of the atmosphere – troposphere to stratosphere, where chlorine atoms are released by the action of UV radiations on them. Liberation of chlorine atoms leads to the conversion of ozone into molecular oxygen. One chlorine atom can destruct 10,000 ozone molecules, causing ozone depletion. Ozone hole formation will result in an increased concentration of UV-B radiations on the surface of earth. The UV – B is known to damage DNA, activating the process of skin ageing. Also, it causes darkening of skin and skin cancer. In humans, high levels of UV-B causes corneal cataract.