Q:12
COMPOSITION
The ozone layer is a region in the Earth's stratosphere that
contains a high concentration of ozone (O3), a molecule made up of three oxygen
atoms. The composition of the ozone layer is:
- Ozone (O3): 90-95%
- Oxygen (O2): 5-10%
- Nitrogen (N2): trace amounts
- Water vapor (H2O): trace amounts
- Other gases (such as argon, carbon dioxide, and methane): trace
amounts
The ozone layer is created when ultraviolet radiation from the sun
interacts with oxygen molecules (O2) in the stratosphere, causing them to split
into individual oxygen atoms. These atoms then combine with other oxygen
molecules to form ozone (O3).
It's worth noting that the ozone layer is not a uniform layer, but
rather a region with varying concentrations of ozone. The highest
concentrations are typically found between 20-30 km above the Earth's surface,
and the layer is thicker at the poles than at the equator.
CAUSES OF OZONE LAYER DEPLETION
¹ ² ³:
- Chlorofluorocarbons: These are the most abundant ozone-depleting
substance. These are released by solvents, spray aerosols, refrigerators,
air-conditioners, etc.
- Unregulated Rocket Launches: Uncontrolled rocket launches result
in more depletion of the ozone layer than CFCs do.
- Nitrogenous Compounds: Nitrogenous compounds such as NO2, NO, N2O
are highly responsible for the depletion of the ozone layer.
- Natural Causes: The ozone layer has been found to be depleted by
certain natural processes such as Sun-spots and stratospheric winds. Volcanic
eruptions are also responsible for the depletion of the ozone layer.
OZONE CRUCIAL ROLE IN PROTECTING LIFE ON EARTH BY:
1. Absorbing harmful UV radiation: Ozone absorbs most of the sun's
harmful ultraviolet-B (UV-B) radiation, which can damage living organisms,
causing skin cancer, cataracts, and immune system suppression.
2. Shielding the Earth: Ozone acts as a shield, preventing harmful
radiation from reaching the Earth's surface, protecting humans, animals, and
plants.
3. Supporting photosynthesis: Ozone helps regulate the amount of UV
radiation that reaches plants, supporting photosynthesis and plant growth.
4. Maintaining ecosystem balance: Ozone helps maintain the balance
of ecosystems, supporting biodiversity and the health of aquatic and
terrestrial ecosystems.
5. Protecting human health: Ozone depletion can lead to increased
cases of skin cancer, cataracts, and immune system disorders, making ozone
protection crucial for human health.
6. Supporting food production: Ozone helps regulate the growth and
development of crops, supporting global food production and security.
7. Maintaining atmospheric chemistry: Ozone plays a role in
regulating the Earth's atmospheric chemistry, influencing the formation of
other important atmospheric compounds.
In summary, ozone plays a vital role in protecting life on Earth by
absorbing harmful radiation, supporting photosynthesis, maintaining ecosystem
balance, and protecting human health, food production, and atmospheric
chemistry.
