Heat Transfer, Sea/Land Breezes, Winds, Coriolis Effect, Chapter 7 Lesson 1

- Winds Angle of the Sun’s Rays Energy from the sun strikes Earth most directly near the equator. Near the poles, the same amount of energy is spread out over a larger area.

Lesson 1 b What affects air temperature? South Pole North Pole June (summer in Northern Hemisphere) Dec. (winter in Northern Hemisphere) Discuss the Main Idea How does the concentration of light change on the area of the ball? Students should observe that the concentration of light lessens along the ball's surface as they move farther away from the direct angle of light. Develop Vocabulary Insolation: Tell students that the word insolation refers to the act of exposing something to sunlight. Have them practice using the term in sentences, and make sure that they do not confuse it with the word insulation. Quick Check (Critical Thinking) Why does the angle of insolation change between midday and evening, and how does this affect the air temperature? The angle of insolation decreases because of Earth's rotation, and the air temperature usually decreases. Insolation is the amount of the Sun’s energy that reaches Earth at a given time and place. Lesson 1 b

How Heat Is Transferred - Heat Transfer How Heat Is Transferred Heat is transferred in three ways: radiation, conduction, and convection.

Temperature and the Movement of Molecules - Heat Transfer Temperature and the Movement of Molecules The iced tea is cold, so its molecules move slowly. The herbal tea is hot, so its molecules move faster than the molecules in the iced tea.

Lesson 1 c What is air pressure? cool air warm air Air pressure is the force exerted on a given area by the impacts of gas particles in constant motion. sea breeze warm air Discuss the Main Idea What force causes the balloon to expand? Air pressure What is wind? Moving air Develop Vocabulary Air pressure: Tell students that they should look at both words to understand the meaning of the two words together. Air pressure is simply “the pressure of the air.” Convection cell: Tell students that convection is a form of heat transfer. Warm air rises and cool air sinks. Convection is a natural way that heat is moved from one location to another. Sea breeze, land breeze: Tell students that they can remember what sea breezes and land breezes are by remembering that the breezes are named for where they come from. A land breeze comes from land, and a sea breeze comes from the sea. They should remember that in both cases, the cooler air is the air that is moving. Use the Visuals Have students look at the visuals of sea breezes and land breezes on page 375. Ask: What happens to the warmer air? It rises, creating space for new air to move into its previous location. Quick Check (Critical Thinking) What role do changing air temperatures play in a convection cell? In a convection cell, warm air rises and is replaced by surrounding cooler air. As the warm air cools, it sinks, and completes the cycle. cool air land breeze Lesson 1 c

- Winds Coriolis Effect As Earth rotates, the Coriolis effect turns winds in the Northern Hemisphere toward the right.

- Winds Global Wind Belts A series of wind belts circles Earth. Between the wind belts are calm areas where air is rising or falling.

Lesson 1 d What are global winds? Discuss the Main Idea What causes winds to curve along Earth's surface? Earth's rotation Develop Vocabulary Coriolis Effect: Word Origin Tell students that the Coriolis Effect is named for French scientist Gaspard-Gustave Coriolis, who described the effect in 1853. Quick Check (Critical Thinking) What causes global wind patterns? They are caused by convection air currents that are affected by Earth's rotation. Lesson 1 d

- Winds Jet Streams The jet streams are high-speed bands of winds occurring at the top of the troposphere.

Relating Cause and Effect - Winds Relating Cause and Effect As you read, identify how the unequal heating of the atmosphere causes the air to move. Write the information in a graphic organizer like the one below. Effects Warm air expands, becomes less dense, and rises. Cause Cold, more dense air sinks. Unequal heating of the atmosphere Dense cold air has a higher pressure than less dense warm air. Wind blows from areas of higher pressure to areas of lower pressure.