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. What is Air Pressure?
We don’t think about it, but we are actually living at the bottom of a large pool of air. This large pool of air is called the atmosphere. It is made up of mostly colorless, odorless gases. These include nitrogen, oxygen, and carbon dioxide.
The weight of all this air weighing down on us is what’s known as air pressure. The more air that is above us, the higher the air pressure will be. 

4. At sea level, the average air pressure is about 15 pounds for every square inch of surface area. At greater heights, the air pressure is lower, because there’s less air above weighing down.

5. What is Air Pressure? 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.

6. Air Pressure
is not the same everywhere on earth.

7. Video:

8. 3 Things that affect Air Pressure are
Altitude
Humidity
Temperature

9. Altitude Air pressure decreases whenever, or increases. Temperature
Humidity
Altitude

10. Temperature Affects Air Pressure
Warmer air brings lower air pressure.

11. Altitude Affects Air Pressure
As the altitude increases the pressure decreases.
The people at the bottom of the pyramid can feel all the weight and pressure of the people on top (high pressure). The person on the top doesn’t feel any weight (less pressure)

12. Humidity Affects Air Pressure
In addition to gases, the air also contains moisture.
As the humidity or moisture in the air increases the air pressure
decreases

13. In low air pressure, air molecules are moving faster and are farther apart.
In high air pressure, air molecules are moving slower and are closer together.

14. Warm air rises resulting in lower pressure
Warm air rises resulting in lower pressure. On the other hand, cold air will sink making the air pressure higher.
High Pressure = NICE Weather
Low Pressure = STORMY

15. Air pressure and weather

16. Air moves from regions of HIGH pressure to regions of LOW pressure.

17. Temperature, Density, and Pressure:
As air is heated it rises and becomes less dense air pressure decreases
As air is cooledit sinks and becomes more denseair pressure increases

18. 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 of mercury.

19. You are done with your guided notes
You are done with your guided notes! Please move on to your IWT for today!