6.1 Intro to the atmosphere

Guiding question

How do atmospheric systems contribute to the stability of life on Earth?

Click here for a Quizlet flashcard set about topic 6.1 Introduction to the atmosphere.

SL and HL knowledge statements

6.1.1 The atmosphere forms the boundary between Earth and space. It is the outer limit of the biosphere and its composition and processes support life on Earth.

This short animated video provides a brief overview of Earth’s atmosphere.

Crash Course has an excellent video lesson about our atmosphere.

6.1.2 Differential heating of the atmosphere creates the tricellular model of atmospheric circulation that redistributes the heat from the equator to the poles.

6.1.3 GHGs and aerosols in the atmosphere absorb and re-emit some of the infrared (long-wave) radiation emitted from the Earth’s surface, preventing it from being radiated out into space. They include water vapour, carbon dioxide, methane and nitrous oxides (GHGs) and black carbon (aerosol).

MinuteEarth brings us this clear and well-animated explanation of the greenhouse effect that makes this planet habitable.

6.1.4 The greenhouse effect keeps the Earth warmer than it otherwise would be due to the broad spectrum of the Sun’s radiation reaching the Earth’s surface and infrared radiation emitted by the warmed surface then being trapped and re-radiated by GHGs.

Knowledge statements for HL only

6.1.5 The atmosphere is a dynamic system, and the components and layers are the result of continuous physical and chemical processes.

Neil deGrasse Tyson is one of my science heroes because he can so clearly communicate complex ideas in language and images that everyday people can understand. This video is a masterpiece in explaining the characteristics of each part of Earth’s atmosphere. Caution: a few mild swear words appear in this video.

6.1.6 Molecules in the atmosphere are pulled towards the Earth’s surface by gravity. Because gravitational force is inversely proportional to distance, the atmosphere thins as altitude increases.

6.1.7 Milankovitch cycles affect how much solar radiation reaches the Earth and lead to cycles in the Earth’s climate over tens to hundreds of thousands of years.

This video will help you understand some of the connections between variation in Earth’s orbits and changes in our climate over geological timescales.

6.1.8 Global warming is moving the Earth away from the glacial–interglacial cycle that has characterized the Quaternary period, toward new, hotter climatic conditions.

6.1.9 The evolution of life on Earth changed the composition of the atmosphere, which in turn influences the evolution of life on Earth.

Practical activities

Examine the impact of albedo on atmospheric temperature.
Study the effect of temperature on photosynthesis.
Investigate the correlation between CO2 levels and biomass production.

Possible engagement opportunities

Turn these into CAS suggestions connected to the UN SDGs.

Citizen science and voluntary agencies offer opportunities for students to participate in gathering knowledge of the atmosphere and the impacts of air pollution.

Happy learning!