1. The Atmosphere – extends more than 10 000 km above the Earth’s surface

2. The Atmosphere
Definition: It is the layer of air surrounding the Earth.
It is made of gases that are essential for life!
They block UV and other dangerous rays from the sun.
They ensure stable climate on Earth.
Include: 02 = For Cellular Respiration
CO2 = For Photosynthesis

3. The Atmosphere
The air is a mixture of gases, especially nitrogen and oxygen, that makes up the atmosphere!
Proportions will changes at high altitude (100 km)
Relative humidity: the proportion of air that is made up of water. It is responsible for cloud formation and precipitation. It can reach 4% of the air volume.
Pollen!

4. Composition of the atmosphere at low altitude

5. The Atmosphere Divided in 5 layers.
The higher the altitude, the fewer the air particles in the atmosphere (density decreases).

7. Layer 1 – Troposphere (0 to 15 km)
Include most meteorological phenomena.
Include storms and cloud formation.
The temperature drops of 6.5°C with every 1000m.

8. Layer 2 – Stratosphere (15 to 50 km)
This is where ultraviolet rays are absorbed
(ozone layer)
In this layer, temperature increases with altitude.
Air particles are increasingly rare!

9. Layer 3 – Mesosphere (50 to 80 km)
The coldest layer of the atmosphere.
The temperature decreases with altitude.
Almost no air!
It can reach -80°C

10. Layer 4 – Thermosphere (80 to 500 km)
It absorbs much of the sun’s rays.
The hottest layer : temperature can reach 1800°C at high elevation.
Celestial bodies such as meteors burn in this layer (ex: shooting stars).
Polar auroras (aurora borealis) form in this layer.

11. Layer 5 – Exosphere (500 km and more)
Almost completely empty.
Almost no air; we can’t gauge its temperature.
This is where we put communications satellites.

12. Atmospheric Pressure It is the pressure of the air.
Air is a gaseous mixture that contains particles that are constantly colliding with one another.
At sea level, the average atmospheric pressure is 101.3
kilopascals (kPa).
1 kilopascal =
100-kg mass
on an area of one
square meter.
CLIP

15. 1.2 Atmospheric Circulation
Definition: the global-scale movement of the layer of air surrounding the Earth.
It rises in the atmosphere above the warm humid regions of the equator and descends over cold and dry regions of the poles.
This phenomenon of CONVECTION helps distribute the solar energy the Earth receives.

17. Coriolis effect – READ PAGE 226
Due to the rotation of the Earth, currents are deflected to the right in the northern hemisphere and to the left in the southern hemisphere.
This effect is greatest at the poles and least at the Equator because of Earth’s near spherical shape.

18. Coriolis effect
CLIP!
CLIP 2 !

19. Air Masses
Definition: large expanse of the atmosphere with relatively uniform temperature and humidity.
Cold air = dense
SINKS!
Warm air = less dense
RISES!

20. In Québec
Our climate is subject to the effect of warm air masses from tropical regions and cold air masses from polar regions. Air masses do not mix!

22. Precipitations!
Front: the line where the two masses meet!

23. COLD FRONTS When a mass of cold air meets a mass of warm air!
Warm air rises rapidly, in a sharp ascent and then cools. Condensations = CLOUDS (CUMULUS)

24. CUMULUS
Definition: Puffy clouds which often produce wind and heavy rain.

25. WARM FRONTS
A warm front forms when a mass of warm air moves toward a mass of cold air, rising gently above cold air and creating clouds in stratified layers.

26. NIMBOSTRATUS
Light clouds in stratified layers. Associated with slow to disparse showers.

27. ANTICYCLONE – SYMBOL: H
Definition: Area of atmospheric circulation surrounding a high-pressure centre. The air turns clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.

28. DEPRESSION – SYMBOL: L
Definition: Area of atmospheric circulation surrounding a low-pressure centre. The air turns counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. L

29. In the Northern Hemisphere!
Depression Anticyclone

30. Weather! Anticyclone Depression -Clear sky -Stable weather -Dry -Sunny
-Cold in the winter
-Clouds
-Precipitation

32. Cyclones! Also known as hurricanes or typhoons
Definition: Tropical storm characterized by violent winds revolving around an area of low pressure.
Winds can reach 360 km/h!
Diameter of up to 800 km

34. CLIP CLIP 2

35. 1.3 The Greenhouse Effect
Definition: Natural process that allows the Earth to retain some of the heat it receives from the sun.
Greenhouse gases : water vapour H20, carbon dioxide CO2, methane CH4 and nitrous oxide N2O.

36. 3 Step Explanation !
1 – Most of the sun’s rays that reach Earth are absorbed by the ground.
2 – Once heated, the ground emits INFRARED rays into the atmosphere. Some pass the atmosphere and are lost in space.
3 – Greenhouse gases trap some of those INFRARED rays and send them back to Earth.

38. How does it work?

39. 1.4 Energy Resources WIND ENERGY
Definition: Energy that can be drawn from
the wind.
HUGE: up to 120 m in height
PROS
CONS
RENEWABLE
No greenhouse gases
No acid rain
No destrcution of ozone layer
Not nice (esthetics)
Unpredictable winds
Energy cannot be stored
Noisy

40. One megawatt wind turbine = 150 to 300 households
CLIP 1
CLIP 2
One megawatt wind turbine = 150 to 300 households