1. Air Pressure Air Pressure Just how does it work?

2. Things that effect Air Pressure Altitude (Elevation) Temperature Humidity (moisture in the air)

3. Altitude The higher the altitude, the lower the air pressure. The lower the altitude, the higher the air pressure.

4. Temperature As the temperature goes up, the air pressure goes down. (hot molecules are further apart- less pressure). As the temperature goes down, the air pressure goes up. ( cold air is more dense than warm air).

5. Humidity Humidity is the amount of moisture in the air. Water vapor weighs less than air molecules. As the air becomes more humid, the air pressure goes down (moist air weighs less than dry air). Drier air has higher pressure because dry air weighs more than moist air, therefore it has greater pressure.