Circulation of Earth's Air and Water Unit 1 Lesson 1

Circulation of Earth's Air and Water Unit 1 Lesson 1

Target: I will be able to model air circulation in Earth's Atmosphere.

Multiple Choice

How would dust get from the Sahara Desert to the Amazon?

• ocean currents

• Global Winds

• local winds

• migration of birds

Wind

The sun warms both the air and Earth's surface, and the sun warms some parts of the Earth more than others. The difference causes pressure differences in the atmosphere and the pressure differences causes wind to blow.

Multiple Choice

When the sun warms the air, what happens to the air?

• the gets more dense and sinks

• the air gets less dense and rises

The Formation of Wind

Temperature also affects the density of air particles. When air gets colder, the particles move more slowly and the particles are packed more closely together.

The Formation of Wind

Because cold air is denser and heavier than the surrounding air, cold air will sink. When cold air reaches the ground, the air spreads out horizontally. The horizontal movement of air is commonly called wind.

Multiple Choice

As air cools, its particles move...

• closer together

• farther apart

Multiple Choice

Cool air will...

• sink

• rise

Multiple Choice

Which letter represents Warm Air?

• A

• B

Convection

Cool air sinks to the surface spreads out and causes the less dense air to rise. This movement of matter due to different densities is called convection.

Multiple Choice

True or false -Cool air pushes warm air upward.

• true

• false

Convection Cells

As warm air moves upward, it loses energy to other air particles. The warm air becomes cooler and sinks. Then it becomes warm again - cools and sinks again. This pattern is called a Convection Cell.

Multiple Choice

In the diagram of a Convection Cell, warm air will push up the cold air.

• true

• false

Effect of Earth's Rotation

The Earth's rotation has an effect on matter in the Earth's atmosphere.

Wind and the Coriolis Effect

The spinning of Earth of its axis causes a similar a deflection of Earth's Winds. This effect of Earth's rotation on the pathway of the wind is called the Coriolis effect. As Earth spins, wind in both hemispheres curves.

Formation of Wind Belts

Cooler, denser air sinks along bands of high pressure. Warmer, less dense air rises along bands of low pressure. This pattern of vertically moving air, curving horizontal winds, and bands of high and low pressure forms 3 wind belts in each hemisphere.

Multiple Choice

Where are the Doldrums located?

• at the 60 degrees N latitude line

• at the 30 degress S latitude line

• where the Northeast trade winds are located

• at the Equator

Global Winds

The sun's rays hit parts of the Earth at different angles. This uneven heating of the Earth's surface causes the equator to receive more sunlight than the poles. The unequal heating of the Earth's surface & the Coriolis efface cause the Global Winds. The Global winds blow in a steady direction across the Earth.

Multiple Select

What are the two things that cause Global Winds? (check all that apply)

• the unequal heating of Earth's Surface

• moonlight

• the tides

• the Coriolis Effect

Multiple Choice

The Global winds move across the entire Earth.

• true

• false

Multiple Choice

In the diagram pictured, what type of Winds are being represented?

• local winds

• Global Winds

Multiple Choice

In which direction will the wind be moving in this diagram?

• toward land

• toward the lake

Multiple Choice

Why is the wind moving toward land in this diagram?

• the land is hotter so the air is more dense and will flow out toward the lake

• the water is cooler so the air is more dense and will flow out toward the land