Earth's Atmosphere: Composition, Layers, and Solar Heating

What is the major component of clean, dry air?

Nitrogen (N) - 78%

What gas absorbs heat energy from Earth and is present at 0.0397% in the atmosphere?

Carbon dioxide (CO2)

What is the maximum percentage of water vapor in the air?

Up to about 4% of the air's volume

What are aerosols?

Tiny solid and liquid particles that can reflect sunlight and help form clouds.

What is ozone composed of?

Three atoms of oxygen (O3)

Where is ozone concentrated in the atmosphere?

Between 10 to 50 kilometers (6 to 31 miles) above the surface.

What is the temperature change rate with altitude?

Temperature drops 6.5 degrees C per 1000 meters.

How often does Earth rotate on its axis?

Once every 24 hours.

What causes the seasons on Earth?

Changing Sun angle and changing length of daylight.

What is the axial tilt of Earth?

23½ degrees.

When does the summer solstice occur?

June 21-22.

What happens during the winter solstice?

The vertical rays of the sun are at the Tropic of Capricorn.

What is an isotherm?

A line connecting places of equal temperature.

What is the greenhouse effect?

The warming of Earth's surface due to trapped heat by greenhouse gases.

What are the mechanisms of heat transfer in the atmosphere?

Conduction, convection, and advection.

How does albedo affect temperature variations?

Water has a high albedo during sunrise and sunset and low during mid-day.

What is the age of the Earth?

4.6 billion years.

What is Earth System Science?

The study of Earth as a system consisting of interdependent parts and cycles.

What is a closed system?

A system that is self-contained, such as an automobile cooling system.

What is a positive feedback mechanism?

A mechanism that amplifies changes in a system, such as global warming.

What is the scientific method?

A systematic approach to gaining knowledge through observation, hypothesis, and experimentation.

What is a hypothesis?

A tentative or untested explanation for a phenomenon.

What is a scientific theory?

A well-established explanation supported by many facts that allows predictions about natural phenomena.

What is the goal of science?

To discover patterns in nature and use knowledge to make predictions.

What are the four spheres of Earth?

Hydrosphere, atmosphere, geosphere, and biosphere.

What is the role of the Sun in Earth System Science?

It drives external processes such as weather and ocean circulation.

What is the significance of chlorofluorocarbons (CFCs)?

They have depleted the ozone layer.