Earth's Atmosphere: Composition, Greenhouse Effect, Layers

Air Composition

• The atmosphere is a mixture of gases, tiny dust particles, and other entities.
• Nitrogen makes up 78% of the atmosphere.
• Oxygen makes up 21% of the atmosphere.
• Argon makes up 0.93% of the atmosphere.
• Carbon dioxide makes up 0.03% of the atmosphere.
• Other gases make up 0.04% of the atmosphere.

Greenhouse Effect

• Carbon dioxide released into the atmosphere traps heat radiated from the Earth.
• This effect is called the greenhouse effect.
• Without the greenhouse effect, Earth's temperature would be too cold to support life.
• Increased levels of carbon dioxide, from sources like factory smoke and car fumes, intensifies heat retention.
• This leads to a rise in global temperature, called global warming
• Resulting in snow melt and sea-level increases, causing coastal flooding.

Layers of the Atmosphere

• The atmosphere is divided into five layers: Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere.
• Troposphere is the layer closest to Earth, and where weather phenomena like rain and hail occur.
• Stratosphere contains the ozone layer, shielding the Earth from harmful UV rays.
• Mesosphere is the layer where many meteors burn up.
• Thermosphere is a very hot layer, with temperatures increasing with altitude.
• Exosphere is the outermost layer, extending into space, and where the atmosphere thins out.

Weather and Climate

• Weather refers to the short-term conditions of the atmosphere, like temperature, humidity, and precipitation.
• Climate is the average weather condition of a place over a long period.
• Temperature is measured using a thermometer.
• Air pressure measures air's force and decreases with height.
• Insolation is the incoming solar energy.
• Winds are horizontal movement of air from high to low pressure areas.

Types of Rainfall

• Convectional rainfall occurs when the sun heats the Earth's surface, causing warm air to rise and cool.
• Orographic rainfall happens when moist air is forced to rise over a mountain.
• Cyclonic rainfall results from the air pressure changes associated with a cyclone.

Cyclones

• Cyclones are severe storms characterized by high winds, heavy rains, and a low-pressure center.
• Cyclones are especially common along India's eastern coast.
• Extreme winds, tidal surges, and heavy rains are main factors that cause damages during cyclones.

Moisture

• Water evaporates into water vapour.
• Moisture in the air measures humidity.
• Warmer air can hold more moisture.
• Condensation occurs when vapor cools and forms water droplets, leading to clouds and precipitation.

Explore the composition of Earth's atmosphere, including nitrogen, oxygen, argon, and carbon dioxide percentages. Understand the greenhouse effect and its role in trapping heat. Learn about the five distinct layers of the atmosphere: troposphere, stratosphere, mesosphere, thermosphere, and exosphere.