1. Air pressure is the force exerted by the weight of air molecules in the atmosphere on a given surface area.
2. A barometer is an instrument used to measure atmospheric pressure.
3. The two main causes of air pressure changes are temperature differences and altitude (height above sea level).
4. Warm air is less dense than cold air, so it rises; cold air is denser, so it sinks.
5. When air contains more water vapor, the air pressure decreases because water vapor molecules are lighter than nitrogen and oxygen molecules.
6. When air pressure is falling, the weather will likely become cloudy, windy, or rainy.
7. When air pressure is rising, the weather will likely become clearer and calmer.
8. Wind moves from high-pressure areas to low-pressure areas.
9. A north wind means the wind is blowing from the north toward the south; a southeasterly wind means the wind is blowing from the southeast toward the northwest.
10. Cold front:
- Time of Day: Often late afternoon or evening
- Temperature: Decreases
- Pressure: Drops then rises
- Precipitation: Showers or thunderstorms possible
11. Warm front:
- Time of Day: Often early morning or midday
- Temperature: Increases
- Pressure: Gradually falls
- Precipitation: Steady rain or drizzle
Parent Tip: Review the logic above to help your child master the concept of air pressure worksheet middle school.
