Word Splash Particles spread out riseParticles spread out rise Less denseheated fasterLess denseheated faster Vibratesinking planetsVibratesinking planets

Air Pressure Ms. Twardowski 8 Green Central Middle School

What is Air Pressure? Air Pressure: Is the force/pressure exerted on any object by the Earth’s atmosphere.Air Pressure: Is the force/pressure exerted on any object by the Earth’s atmosphere. Make TWO columns “L” = stands for Low Pressure system. Warm air rises, so there is less pressure put on objects by the atmosphere.“L” = stands for Low Pressure system. Warm air rises, so there is less pressure put on objects by the atmosphere. “H” = stands for High Pressure System. Cooler air sinks, so there is more pressure put on objects.“H” = stands for High Pressure System. Cooler air sinks, so there is more pressure put on objects.

Synonyms Air PressureAir Pressure Atmospheric PressureAtmospheric Pressure Barometric Pressure (A ‘barometer’ is used to measure air pressure)Barometric Pressure (A ‘barometer’ is used to measure air pressure)

High Pressure Systems. AIR/WIND ALWAYS MOVES FROM AREAS OF HIGH TO LOW PRESSURE (Write this down!!) Cool air sinking Clockwise rotation Clearer skies (because air sinks and the pressure creates friction/HE that evaporates the moisture in the air).

Low Pressure Systems. Warmer Air Rising Moves in a counter- clockwise rotation. Warmer temperatures. Clouds and precipitation (because warm air rises and then cools/condenses to form clouds).

False/No = Red True/Yes = Green High Pressure is associated with cool, sinking air and clearer skies.High Pressure is associated with cool, sinking air and clearer skies.

False/No = Red True/Yes = Green Air/Wind moves from Low to High Pressure systems.Air/Wind moves from Low to High Pressure systems.

False/No = Red True/Yes = Green Atmospheric Pressure, Air Pressure, and Barometric Pressure are synonyms.Atmospheric Pressure, Air Pressure, and Barometric Pressure are synonyms.

With this movement of air – MOST weather moves from WEST to EAST. WHY do you think this is?WHY do you think this is? WHAT do you think makes most weather move this way?WHAT do you think makes most weather move this way?

New concept: Convection Currents (don’t copy this) When air is heated, the particles begin to move faster, spread further apart and become less dense.When air is heated, the particles begin to move faster, spread further apart and become less dense. As the air becomes less dense, it will begin to rise.As the air becomes less dense, it will begin to rise. As this air rises, it slowly begins to cool and the particles slow down, come closer together and become denser and sink.As this air rises, it slowly begins to cool and the particles slow down, come closer together and become denser and sink.

Sea Breezes (copy AND draw this! Don’t forget the Sun!) A sea breeze develops when the land become much warmer than the sea on a sunny day.A sea breeze develops when the land become much warmer than the sea on a sunny day. Therefore, the air over the land is warmer, less dense (low pressure) and begins to rise over the land.Therefore, the air over the land is warmer, less dense (low pressure) and begins to rise over the land. As this warmer air rises, it begins to cool and becomes denser (higher pressure) and sinks.As this warmer air rises, it begins to cool and becomes denser (higher pressure) and sinks. Air moves from high to low pressure. This process gives you a convection cycle.Air moves from high to low pressure. This process gives you a convection cycle.

Land Breezes (copy AND draw this! Don’t forget the moon!) A land breeze develops when the land cools down much more than the sea during the nighttime.A land breeze develops when the land cools down much more than the sea during the nighttime.

Summary Questions (What did you learn?) Put up your red/green card! 1. Convection is when Heat Energy moves through a solid.

Summary Questions (What did you learn?) Put up your red/green card! 2. A Sea Breeze means: the ‘breeze’ is coming ‘from’ the sea.

Summary Questions (What did you learn?) Put up your red/green card! 3. Air/Wind always moves from HIGH to LOW pressure.

Summary Questions (What did you learn?) Put up your red/green card! 4. Land Breezes happen during the night.

Summary Questions (What did you learn?) Put up your red/green card! 5. Land Breezes happen during the night.

Summary Questions (What did you learn?) 1.Take out a sheet of blank notebook paper. 2.Put a heading on the paper. 3.Number your paper from

Summary Questions (True or False) 1.Warm air rises.

Summary Questions (True or False) 2. Low pressure systems are associated with cloudy weather and precipitation.

Summary Questions (True or False) 3. Air flow counter-clockwise around a LOW pressure system.

Summary Questions (True or False) 4. Low pressure systems are associated with WARMER temperatures.

Summary Questions (True or False) 5. High pressure systems are associated with clear skies.

Summary Questions (True or False) 6. Air flows counter-clockwise around a high pressure system.

Summary Questions (True or False) 7. Cooler air sinks.

Summary Questions (True or False) 8. Sea Breezes happen during the day.

Summary Questions (This sentence is false. Change ONE word to make it true. Write the TRUE statement on your paper.) 9. Warm air rises because it is more dense than the air around it.

Summary Questions (This sentence is false. Change ONE word to make it true. Write the TRUE statement on your paper.) 10. Sea Breezes happen at night when the ocean water is warmer than the land.

Review: Land/Sea Breezes (Partners) Draw BOTH pictures on a sheet of paper. Label the pictures with: –Arrows –L and H (low/high pressure) –The Sun/moon –Warm air rising –Cool air sinking –Land Breeze –Sea Breeze