Composition and Structure of the Atmosphere

Composition and Structure of the Atmosphere

• Atmosphere is a mixture of gases, water vapor, and dust particles surrounding Earth.
• Air is essential for life, containing oxygen for humans/animals and carbon dioxide for plants.
• 99% of atmospheric mass is within 32 km of Earth's surface.
• Air is colorless and odorless, felt as wind.

Atmospheric Composition

• Gases, water vapor, and dust particles make up the atmosphere.
• Proportions of gases change with altitude.
• Oxygen is almost insignificant at 120 km altitude.
• Carbon dioxide and water vapor are found up to 90 km.

Carbon Dioxide

• Carbon dioxide is crucial for Earth's temperature regulation.
• Transparent to incoming solar radiation but opaque to outgoing terrestrial radiation.
• Absorbs/reflects terrestrial radiation back to Earth (greenhouse effect).
• Carbon dioxide levels have increased recently due to fossil fuel burning, contributing to global warming.

Ozone

• Ozone is another important atmospheric component.
• Found between 10-50 km above Earth's surface (ozone layer).
• Acts as a filter, absorbing UV radiation from the sun, preventing it from reaching the Earth's surface.
• Ozone layer is primarily located in the stratosphere.

Water Vapor

• Water vapor is the gaseous form of water in the atmosphere.
• Source of precipitation.
• Amount decreases with altitude and latitude (more near equator).
• Key role in Earth's temperature regulation (acts as blanket).

Dust Particles

• Found in lower atmospheric layers.
• Types vary (sand, soot, salt, ash, pollen).
• Higher concentration in subtropical/temperate regions.
• Condensation nuclei, forming clouds.

Atmospheric Structure

• Divided into layers based on temperature changes.

Troposphere

• Lowest atmospheric layer (0-7 to 20 km above Earth's surface).
• Weather phenomena occur here.
• Temperature decreases with altitude.
• Contains water vapor, dust particles.

Stratosphere

• Above troposphere (0-50 km).
• Very dry (little water vapor).
• Important for flight due to steady winds.
• Contains the ozone layer.
• Temperature increases with altitude (due to ozone absorption of UV).

Mesosphere

• Above stratosphere (50-85 km).
• Coldest atmospheric layer.
• Meteors burn up in this layer.
• Temperature decreases with altitude.

Thermosphere

• Above mesosphere (80-400 km).
• Temperature rises significantly with altitude (because of radiation absorption).
• Radio waves are reflected by this layer.
• Aurora and satellites occur here.

Ionosphere

• Lower portion of the thermosphere.
• Contains electrically charged particles (ions) created by solar/cosmic radiation.

Exosphere

• Outermost atmospheric layer.
• Molecules escape into space.
• Extends to 10,000 km.

Explore the composition and essential elements of Earth's atmosphere in this quiz. Understand the role of gases, including carbon dioxide and ozone, in maintaining life and regulating temperature. Test your knowledge on the atmospheric layers and the importance of air for life on Earth.