Lesson 1How does air move?

About 2/10-

oxygen

CO2, water vapor,

& other gases

About 8/10-

nitrogen

gases in air

Chart of gases that make up atmosphere

5 layers of Earth’s atmosphere

eexosphere

tthermosphere

mmesosphere

sstratosphere

ttroposphere

(weather)

air pressure decreases as air pressure decreases as you move up higher you move up higher

b/c gas particles get farther b/c gas particles get farther apart- less air above youapart- less air above you

Air Pressure-Activity1. Lay a ruler on a table with about 3" (8 cm) hanging over the edge.

2. Lay a sheet of printer paper on the part of the ruler in direct contact with the table.

3. Press the paper against the table until it is flat as possible.

4. Press down on part of the ruler hanging over the edge.

5. Repeat the above steps except replace the printer paper with a large sheet of opened newspaper in the second step.

convection current

• gases or liquids rise & sink in circular path due to differences in temp.

Make convection currents

cool air warm air

1. particles closer

together

2. heavier

1. particles farther apart

2. lighter

create convection

currents

wind

• air moves from place of high air pressure place of low air pressure

• move from west east in U.S.

NorthNorth

SouthSouth

WestWest EastEast

jet stream

• band of very fast wind formed by different temps. between convection currents

• found high above ground

• change temp, winds & precipitation

The Jet Stream [00:34]

5 layers of Earth’s atmosphere

eexosphere

tthermosphere

mmesosphere

sstratosphere

ttroposphere

As altitude increases, how does air pressure change? Why?

• Air pressure decreases as you go up through the atmosphere because the gas particles in the air get farther apart and there is less air above you.

•Nitrogen

•Oxygen

•Other gases

about 8/10

about 2/10

water vapor, carbon dioxide, helium, etc.

What causes convection currents?

• Different temperatures cause convection currents. Cooler air is heavier than warm air. Cool air will sink, forcing warm air to rise.

In what direction do surface winds over the United States

generally blow?

• Winds generally blow from west to east in the United States.

At night, land cools more than water. Air above land will be cooler than air above the

water. What conclusion can you draw about

convection currents near the ocean at night?