1. Air Pressure

2. Can you feel air pressure?
When you take off or land in an aircraft, your ears may hurt or feel uncomfortable. This is because your eardrums can feel changes in air pressure as the aircraft moves quickly up and down.
But what is air pressure?

3. Air Pressure
Prompt students to wave their hands in the air. Teacher: What do you feel? What are you feeling? What would it feel like if there wasn’t any air?

4. What is Air Pressure?
It is caused by the weight of all the air in the atmosphere pressing down on Earth.
It is also known as atmospheric pressure.
Air pressure changes with the height and also when air warms up or cools down.
Changes in air pressure cause changes in the weather.

5. Air Pressure
Air’s pressure is pretty heavy at sea level. It is equivalent to (like) an elephant balancing on a desk!

6. Air Pressure
There is more pressure near the Earth’s surface and less when you go further into the atmosphere.

7. Turn and Talk and write it Atmosphere is _____________.
Quick!
What is atmosphere?
Turn and Talk and write it
Atmosphere is _____________.
After 2 minutes of students writing in their notes ask a student to come up and write it on the white board or type it into the computer.

8. Measuring Air Pressure
Air Pressure is measured in millibars (mb) on a barometer.
The simplest kind of barometer is a mercury barometer and pressure is measured in mm (in) of mercury.
An aneriod barometer can measure more conveniently.
A barograph is a special kind of barometer, which records continuous changes in air pressure.

9. Photos I
A aneroid barometer

10. Photos II
A barograph

11. What do you remember about
Hot and Cold air?
Draw a picture here
After a few minutes have them compare notes with table group. Did everyone get the same answer? Make sure everyone agrees.

12. Differences in air pressure
Low Pressure
When air rises, it leaves behind an area of lower pressure, because the upward- moving air is not pressing down so hard on the surface.

13. Low Pressure Hot Air Low Pressure looks like this in weather: Creates
What would the air molecules look like? How does the density of the molecules affect the amount of pressure? Why would that create nice weather?
Prompt students to write answers in their power point notes.

14. High Pressure
Areas of high pressure are formed where air is sinking back down, and so pushing down harder.
>> see the diagram

15. High Pressure looks like this in weather:
Cold Air
High Pressure looks like this in weather:
Creates
High Pressure
What would the air molecules look like? How does the density of the molecules affect the amount of pressure? Why would that create nice weather?
Prompt students to write answers in their power point notes.

16. Since there are many areas of high and low pressure above the Earth’s surface due to uneven surface heating.
Air moves from high pressure to low pressure forming winds.
As a result, the greater the difference between the high pressure and low pressure areas is, the higher the wind speed is.

17. Highs and Lows Pressure is different all over the world.
Lows are areas of low pressure with the lowest pressure at the center.
Lows usually bring wet, cloudy weather.

18. Highs are areas of high pressure with the highest pressure at the center.
Highs bring sunnier, and dry weather.
The way these move from day to day causes the changes in the weather.

19. Air Pressure is like blankets
When you’re at sea level it’s like you’re under ______ of blankets.
When you’re on a tall mountain it’s like you’re under ________ blankets
Prompt students to write into the blanks in their notes. Have them read the completed sentences to a partner.

20. Quick Write!
Where is air pressure higher? On a mountain or near the beach? Why?
Prompt Students to write their ideas in their notes. They then share out answers and reasons.

21. Compare and Contrast Your Turn!
What is low and high pressure? What are their causes? How are they different or the same?
Complete the worksheet. Make sure you include both diagrams and writing. Fill out the whole sheet.
Hand out air pressure worksheet.