Ozone Layer
I. Formation
II. Mechanism of depletion
III. Effects of ozone depletion
Introduction
• Ozone (O3) is a triatomic form of oxygen.
• Three atoms of oxygen bonded to form an ozone molecule.
• A layer in the earth's stratosphere at an altitude of about 10 km (6.2
miles) containing a high concentration of ozone, which absorbs most
of the ultraviolet radiation reaching the earth from the sun.
• The ozone layer is mainly found in the lower portion of the
stratosphere.
• The presence of ozone enabled organisms to develop and live on
the land.
• Ozone played a significant role in the evolution of life on Earth
Good ozone:
• In the stratosphere ,
• Absorb UV radiations
• protecting us from ultraviolet radiations
Bad ozone:
• Present in the lower atmosphere or troposphere
• This Ozone is a pollutant produced by photochemical reactions
involving sunlight , nitrogen oxides, hydrocarbons and diatomic
oxygen.
, Thus, ozone plays two very different roles in global environmental change:
→ One in the stratosphere as a shield against harmful ultraviolet
radiation,
→ And another nearer the ground in the troposphere as a greenhouse gas
find a health hazard.
Ozone layer formation:
• Ozone is produced naturally in the stratosphere when highly
energetic solar radiation strikes molecules of oxygen (O2)
• and cause the two oxygen atoms to split apart in a process called
photolysis.
• If a freed atom collides with another O2, it joins up, forming ozone O3
O2 + UV → O + O
O + O 2 → O3
• Ozone is also naturally broken down in the stratosphere.
I. Formation
II. Mechanism of depletion
III. Effects of ozone depletion
Introduction
• Ozone (O3) is a triatomic form of oxygen.
• Three atoms of oxygen bonded to form an ozone molecule.
• A layer in the earth's stratosphere at an altitude of about 10 km (6.2
miles) containing a high concentration of ozone, which absorbs most
of the ultraviolet radiation reaching the earth from the sun.
• The ozone layer is mainly found in the lower portion of the
stratosphere.
• The presence of ozone enabled organisms to develop and live on
the land.
• Ozone played a significant role in the evolution of life on Earth
Good ozone:
• In the stratosphere ,
• Absorb UV radiations
• protecting us from ultraviolet radiations
Bad ozone:
• Present in the lower atmosphere or troposphere
• This Ozone is a pollutant produced by photochemical reactions
involving sunlight , nitrogen oxides, hydrocarbons and diatomic
oxygen.
, Thus, ozone plays two very different roles in global environmental change:
→ One in the stratosphere as a shield against harmful ultraviolet
radiation,
→ And another nearer the ground in the troposphere as a greenhouse gas
find a health hazard.
Ozone layer formation:
• Ozone is produced naturally in the stratosphere when highly
energetic solar radiation strikes molecules of oxygen (O2)
• and cause the two oxygen atoms to split apart in a process called
photolysis.
• If a freed atom collides with another O2, it joins up, forming ozone O3
O2 + UV → O + O
O + O 2 → O3
• Ozone is also naturally broken down in the stratosphere.
