The formation of ozone holes in the Antarctic Region has been a cause of concern. What could be the reason for the formation of this hole?
- Presence of prominent tropospheric turbulence; and inflow of chlorofluorocarbons
- Presence of prominent polar front and stratospheric clouds; and inflow of chlorofluorocarbons
- Absence of polar front and stratospheric clouds; and inflow of methane and chlorofluorocarbons
- Increased temperature at polar region due to global warming
Explanation
Option (b) is correct
- Ozonosphere lies between 20 km and 55 km from the earth’s surface and spans the stratosphere and lower mesosphere. But the highest concentration occurs between 20 km and 30 km.
- To destroy ozone, ozone-depleting substances (ODS) need to be carried up to the lower levels of the stratosphere. • The only weather phenomena that can reach this level are Polar Vortex and towering tropical cumulus clouds. But towering cumulus clouds do not occur at the poles.
- Question: The formation of ozone hole in the Antarctic region has been a cause of concern. What could be the reason for ozone depletion at poles?
- Presence of prominent tropospheric turbulence: they do not reach the stratosphere.
- Presence of a prominent polar front: essential to keep the polar vortex in its place. Polar vortex gives rise to stratospheric Clouds.
- Presence of stratospheric Clouds: they have the necessary ingredients (nitric acid and sulfuric acid) to amplify ozone depletion.
- Absence of polar front and stratospheric clouds: polar vortex slips into the temperate region.
- Inflow of methane: methane (CH4) is not in the list of ozone-depleting substances. It does not contain a halogen like chlorine, bromine, fluorine, etc. But it reacts with halogens to create reservoir compounds.
- Increased temperature in the polar region due to global warming: this does not have any direct impact on ozone depletion at the poles
