Question

Ozone hole refers to
A. Hole in ozone layer
B. Decrease in thickness of ozone layer in stratosphere
C. Decrease in the ozone layer in troposphere
D. Increase in the thickness of ozone layer in troposphere

Answer 1

Hint: When the oxygen-depleting substances like CFCs, HFCs, bromide etc. the ultraviolet light rays split them to unleash the reactive species of atomic number 17 and halogen. These reactive species react with the gas to unleash the O, thereby inflicting the depletion of gas. The hole is that the place wherever the thickness of the ozonosphere is extremely skinny and also the concentration is a smaller amount than 220 DU. It's seen over the Antarctic continent thanks to the method of polar vortex and formation of polar stratospheric clouds.

Complete Answer:
- The term ‘ozone hole’ refers to the depletion of the protecting ozonosphere within the higher atmosphere (stratosphere) over Earth's polar regions. People, plants, and animals living underneath the whole area unit injured by the radiation currently reaching the Earth's surface—where it causes health issues, from eye harm to carcinoma.
- Stratospheric gas is continually made by the action of the sun's actinic radiation on O molecules (known as chemical science reactions) although gas is formed primarily at tropical latitudes, large-scale air circulation patterns within the lower layer move gas toward the poles, wherever its concentration builds up.
- In addition to the present international motion, sturdy winter polar vortices are vital to concentrating gas at the poles. throughout the unendingly dark polar winter, the air within the polar vortices becomes very cold, a necessary condition for polar stratospheric cloud formation.
- Polar stratospheric clouds produce the conditions for forceful gas destruction, providing a surface for atomic number 17 to alter into ozone-destroying kind. they typically last till the sun comes up within the spring.
- In the Eighties, scientists discovered that the ozonosphere was diluting within the lower layer, with notably dramatic gas loss—known because of the "ozone hole"—in the Antarctic spring (September and October).
- Scientists additionally discovered that the dilution within the ozonosphere was caused by increasing concentrations of ozone-depleting chemicals – chlorofluorocarbons or CFCs (compounds with atomic number 17 and/or F connected to carbon) and to a lesser extent halons (similar compounds with halogen or iodine). These chemicals will stay within the atmosphere for many years to over a century.
- At the poles, CFCs attach to ice particles in clouds. Once the sun comes out once more within the polar spring, the ice particles soften, emotionally the ozone-depleting molecules from the ice particle surfaces.
- Once discharged, these ozone-destroying molecules do their dirty work, breaking up the molecular bonds in ultraviolet light radiation-absorbing gas.

Hence the correct answer is option A.

Note: The hole isn't technically a “hole” wherever no gas is a gift, however, is really a vicinity of exceptionally depleted gas within the layer over the Antarctic that happens at the start of hemisphere spring (August–October). The ozonosphere effectively blocks most radiation of wavelengths but 290 nanometres from reaching Earth's surface, as well as sure forms of ultraviolet (UV) and different varieties of radiation that might injure or kill most living things.