This is for educational purposes about our environment as well as the things that contribute to all living thing on earth. Hope you get some sort of knowledge from it :).

1. THE ATMOSPHERE
NATURAL SCIENCES

2. ATMOSPHERE
• The three important gases found in the
atmosphere which support life
The Diagram shows the
idealized Atmosphere,
using various colours to
resemble various layers

3. WHAT IS THE
ATMOSPHERE?
The atmosphere is the layer of gases
that surrounds the earth.
It contains the following mixture gases:
nitrogen, oxygen, argon, carbon dioxide and
other trace gases.
This Photo by Unknown Author is licensed under CC BY

4. Layers of the Atmosphere |
What is Atmosphere : 3:58
https://youtu.be/G4ZIa3qkFkI

5. COMPOSITION
OF THE
ATMOSPHERE
Solids: dust particles and salt crystals.
Liquid: Water in the form of clouds.
Gases: Nitrogen (78%) – plant growth
Oxygen (21%) – respiration
Argon (1%)

6. STRUCTURE OF THE
EARTH.

7. LAYER 1 - TROPOSPHERE
Layer closest to the
earth.
8 – 16 km thick. 8km
(poles) and 16km
(equator)
Contain al the gases
which are essential
for life.
Contains all weather
conditions.
Temperatures
DECREASE with
height.

8. LAYER 2 - STRATOSPHERE
Contains the layer of Ozone (O3).
Ozone absorb all the ultraviolet rays (UV) from the sun.
Temperature INCREASE with height due to the absorption of UV-
rays.
Reasons why planes fly here:
-Little to no turbulence is found in the stratosphere.
-Stratosphere is very dry and few clouds are formed in this
layer.
-All cloud cover is in the lower layer and there are stable
conditions in the stratosphere.

9. LAYER 3: MESOSPHERE
• Extends from around 50 km to 80 km above the Earth's surface.
• The atmosphere reaches its lowest temperature in this layer. Roughly (-90 °C)
• The air density is extremely low.
• This layer is characterised by meteors
• When the air ahead of the meteor compress, the rock heats up from friction and heat thus
resulting in it burning.
• Most meteors are small to medium sized, so they burn up completely before they reach
the earth’s surface, however huge meteors often reach the earth’s crust. Their impact are
referred to as craters. Vredefort crater in Free State is an example of this phenomena
A meteor is a rock
that enters the
atmosphere from
space.
This is also called a
shooting star. Often
one might see a
flashing streak of
light for a moment.

10. VREDEFORT CRATER
This Photo by Unknown Author is licensed under CC BY

11. LAYER 4 : THERMOSPHERE
• The thermosphere is the layer of the atmosphere from 80 km
upwards.
• The density of the air is extremely low. The further away you move
from the Earth, the less dense the concentration of molecules
becomes until the atmosphere becomes space.
• Most satellites that we depend on every day are in Low Earth Orbit
(LEO), orbiting the Earth at an altitude between 160 km and 2,000
km. The International Space Station (ISS) is situated at 370 km in
the thermosphere. This is an international facility in space that is
used for research purposes.
This Photo by Unknown Author is licensed under CC BY

13. REFERENCES
Lutgens, F.K., Tarbuck, E.J. and Tusa, D., 1995. The atmosphere (Vol. 462).
Englewood Cliffs, NJ, USA: Prentice-Hall.
Holton, J.R., Haynes, P.H., McIntyre, M.E., Douglass, A.R., Rood, R.B. and
Pfister, L., 1995. Stratosphere‐troposphere exchange. Reviews of
geophysics, 33(4), pp.403-439.
Plane, J.M., Feng, W. and Dawkins, E.C., 2015. The mesosphere and
metals: Chemistry and changes. Chemical reviews, 115(10), pp.4497-
4541.
Bruinsma, S., Boniface, C., Sutton, E.K. and Fedrizzi, M., 2021.
Thermosphere modeling capabilities assessment: geomagnetic
storms. Journal of Space Weather and Space Climate, 11, p.12.

14. Enjoy your day