6.1 Introduction to the Atmosphere

Significant Ideas

• The atmosphere is a dynamic system that is essential to life on Earth.

• The behaviour, structure and composition of the atmosphere influence variations in all ecosystems.

Knowledge and Understanding

• 1. The atmosphere is a dynamic system (with inputs, outputs, flows and storages) that has undergone changes throughout geological time.

  2. The atmosphere is predominantly a mixture of nitrogen and oxygen, with smaller amounts of carbon dioxide, argon, water vapour and other trace gases.

  3. Human activities impact atmospheric composition through altering inputs and outputs of the system. Changes in the concentrations of atmospheric gases—such as ozone, carbon dioxide, and water vapour—have significant effects on ecosystems.

  4. Most reactions connected to living systems occur in the inner layers of the atmosphere, which are the troposphere (0–10 km above sea level) and the stratosphere (10–50 km above sea level).

  5. Most clouds form in the troposphere and play an important role in the albedo effect of the planet.

  6. The greenhouse effect of the atmosphere is a natural and necessary phenomenon maintaining suitable temperatures for living systems.

Applications and Skills

1. Discuss the role of the albedo effect from clouds in regulating global average temperature.

2. Outline the role of the greenhouse effect in regulating temperature on Earth.

Guidance

1. Students should recognize the atmosphere as a dynamic system. The composition of the atmosphere has changed throughout geological history. Living organisms (biotic components) have transformed the atmospheric composition of the Earth and vice versa throughout history.

2. The use of chemical symbols or chemical formulae for atmospheric gases is not required.

Key Vocabulary

• XYZ

Textbook Reading and/or Activities

Click HERE for a pdf of chapter 4.

• Pages x-xx

  • Challenge Yourself (p.x)

  • Worked Example (p.x-xx)

  • Exercises (p.x)

Notes

i-Biology Notes (Not available)

A detailed set of notes, created by Stephen Taylor, examining U1 - U8 and A1 - A4.

i-Biology Study Questions (Not available)

A series of questions, created by Stephen Taylor, to help check your understanding of the IB learning expectations. This is VERY GOOD practice.

Bioknowledgy Notes (Not available)

A detailed set of notes, created by Chris Paine, examining all of the IB learning expectations.

Bioknowledgy Study Questions (Not available)

A series of questions, created by Chris Paine, to help check your understanding of the IB learning expectations. This is VERY GOOD practice.

Learning Activities

Virtual Lab - The Greenhouse Effect

This activity, prepared by PhET, will provide you with an opportunity to manipulate some of the variables involved in the greenhouse effect to see how they influence global temperatures. (K&U 6 and A&S 2)

Lab - Global Warming in a Jar

This lab activity, originally prepared by Christa McAuliffe Planetarium, will help you better understand the greenhouse effect and how water can act as a moderator of temperature.

Supplemental Reading

Evolution of the Atmosphere

This reading, produced by the University of Michigan, outlines the early atmospheric conditions, its composition and how it has changed over the last 5.5 billion years. (K&U 1-3)

This video examines the structure of Earth's atmosphere and how it relates to climate.