Topic: What layers is the atmosphere built of?

Author: Magdalena Jankun

Target group

First‑grade high school and technical school student, extended programme

Core curriculum

Extended programme

III. Dynamics of atmospheric and hydrological processes: vertical structure of the atmosphere, phenomena and processes in the atmosphere, spatial diversity of climate elements, climate zones and types of climates, movements of sea water, sources and groundwater, river systems, types of lakes.

Student:

1. Shows relationship between the structure of atmosphere and meteorological phenomena and processes.

Purpose of the lesson

You will discuss the atmosphere layers and explain the causes of the greenhouse effect.

Criteria of success

• You will explain the term „atmosphere”;

• name gases that form the air and their percentage share;

• name permanent and variable components of atmospheric air;

• name the layers of the atmosphere;

• discuss the role of the ozone layer;

• characterize the effects of the ozone hole and the greenhouse effect.

Key competences

• communication in the mother tongue;

• communication in a foreign language;

• learning to learn;

• digital competence.

Methods / forms of work

• using ICT tools;

• activity with educational material and multimedia on the e‑textbook platform;

• individual activity, activity in pairs, and collective activity.

Teaching aids

• e‑textbook for teaching geography;

• interactive whiteboard;

• multimedia projector;

• tablets/computers.

Lesson plan overview

Before lesson

The students get familiar with the initial content of the abstract and with an interactive map showing the atmospheric layers at home (flipped lesson). Based on the information learnt and additional messages, the students are to prepare short presentations about the phenomena occurring in particular layers of the atmosphere.

Before classes

1. The teacher begins the lesson with the students’ presentations. This takes about 15 minutes.

2. After the presentations, the teacher briefly summarizes the information provided. The teacher draws the students' attention to the temperature prevailing in each layer.

Realization

1. The teacher emphasizes that the atmosphere is the Earth's coating that is a mixture of gases called the air. It is the most important protective layer of the Earth, because it protects against harmful cosmic radiation, i.e. a stream of protons, electrons and heavy atomic nuclei. It protects against meteoroids that reach its upper layers and most of them are burnt.

2. The students answer the question in the abstract: Think for a while and explain the reason why the layer thickness of the atmosphere above the poles is smaller than above the equator. The students discuss in pairs and then write down their explanations. The selected pairs discuss their conclusions on the class forum.

3. Interactive exercise: matching texts. Match the information to the name of the appropriate atmospheric layer. The students approach the interactive whiteboard one by one and carry out the task.

4. Measuring atmospheric pressure using a barometer. The teacher explains how the barometer works and shows how to read the pressure correctly. Several students make measurements themselves.

5. The students and the teacher watch a film showing how to make a barometer at home. The teacher discusses the results obtained with the help of this device. The teacher gives homework to keen students: make a barometer at home and measure change the air pressure for a few days.

6. Interactive exercise: check the elements in the correct column (permanent components of atmospheric air). The teacher chooses a student who will work on the multimedia board.

Summary

1. At the end of the classes, the teacher gives the students homework: Elaborate the effects of the ozone hole and the greenhouse effect. The work can be presented in any form.

2. The teacher assesses the students' activity during the lesson, appreciating their engagement and commitment.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Earth's atmospheric layers

In the Earth's atmosphere we distinguish 5 main layers characterized by specific features and 4 intermediate layers called pauses. The boundaries between them are conventional and change depending on the geographical latitude, terrain and season of the year.

The closest one to the surface of the earth is the troposphere. Its thickness ranges from 7 km (in winter) to 10 km (in summer) above the poles, and 15‑18 km above the equator. The main feature that allows determining the boundary of the troposphere is the drop in the air temperature with an increase of about 0,6°C per 100 m. In the upper layer of the troposphere, the temperature reaches -55°C (above arctic regions) to -70°C (above equatorial regions).

Above this layer there is a thin tropopause with the constant temperature, and above it there is the stratosphere extending up to a height of about 50 km, in which the air temperature rises to reach 0°C. In the stratosphere there is the ozonosphere – a layer with an increased content of ozone (oxygen in the form of triatomic particles), which reaches the highest concentration at a height of 25‑30 km. It plays a very important role – it protects the Earth against the lethal ultraviolet radiation emitted by the Sun. At the upper boundary of the stratosphere, a few‑kilometre thick stratopause, the temperature is constant.

The next layer is the mesosphere reaching up to around 80 km, in which the temperature constantly decreases down to -70°C and even -100°C. Above the mesopause there is a layer called the thermosphere with a rising temperature of up to 1000°C, and at a height of 500‑600 km, even up to 1500°C. Above its upper boundary – thermopause – there is the exosphere in which the very low‑density air temperature begins to drop down to -273°C in cosmic space. The upper boundary of the exosphere is difficult to be determined.

As the height increases, the atmospheric pressure drops. From approximately 1000 hPa hectopascals at the sea level through 200 hPa at the boundary with the tropopause, 1 hPa at the boundary of the stratopause, up to 0.000 001 hPa in the exosphere.

• Atmospheric air consists of approximately 78% nitrogen, 21% oxygen, less than 1% argon and dozens of other components.

• Most air constituents are present in fixed proportions, only the content of water vapour and carbon dioxide, and some impurities changes quite clearly in time and space.

• The atmosphere is composed of 5 main layers: troposphere, stratosphere, mesosphere, thermosphere and exospheres, and 4 transition layers: tropopause, stratopause, mesopause, and thermopause.

• The air temperature changes depending on the atmosphere layer: it decreases in the troposphere, increases in the stratosphere, decreases in the mesosphere, increases significantly in the thermosphere, and decreases significantly in the exosphere.

• The air temperature near the Earth's surface depends on many different natural factors and on human activity.