Chapter 22 Section 2 Chapter 22 Section 2 Review Page 560Review Page 560

Earth’s AtmosphereEarth’s Atmosphere

1. 1. Explain how radiant Explain how radiant energy reaches Earth.energy reaches Earth.

• Radiation from the sun travels Radiation from the sun travels through space in the form of through space in the form of electromagnetic waves.electromagnetic waves.

2. 2. List and describe List and describe the types of the types of electromagnetic electromagnetic waves.waves.

• Long wavelength: TV/radio Long wavelength: TV/radio waves, microwave, infrared, and waves, microwave, infrared, and visible lightvisible light

• Short wavelength: UV rays, X Short wavelength: UV rays, X rays, Gamma Raysrays, Gamma Rays

Electromagnetic SpectrumElectromagnetic Spectrum

3. 3. Describe how gases Describe how gases and particles in the and particles in the atmosphere interact atmosphere interact with light rays.with light rays.

• Nitrogen, oxygen, and ozone in the Nitrogen, oxygen, and ozone in the upper atmosphere absorbs most short upper atmosphere absorbs most short wavelength radiationwavelength radiation

• CO2 and water vapor absorb CO2 and water vapor absorb infrared radiation in the lower infrared radiation in the lower atmosphere.atmosphere.

• About 50% of visible light reaches About 50% of visible light reaches Earth’s surface. Clouds, particulates and Earth’s surface. Clouds, particulates and gases scatter and reflect much of the gases scatter and reflect much of the light.light.

Formation of OZONEFormation of OZONE

4. 4. Describe how Describe how visible light and visible light and infrared energy warm infrared energy warm Earth.Earth.

• Infrared and visible light that Infrared and visible light that reach Earth’s surface are reach Earth’s surface are absorbed. Heated surfaces absorbed. Heated surfaces radiate heat back into the air radiate heat back into the air where greenhouse gases absorb where greenhouse gases absorb some of the heat.some of the heat.

Infrared radiationInfrared radiation

Infrared ImagesInfrared Images

5. 5. Explain how Explain how variations in intensity variations in intensity of sunlight can cause of sunlight can cause temperature temperature differences on Earth’s differences on Earth’s surface.surface.• Concentrated sunlight at the Concentrated sunlight at the

equator makes the surface equator makes the surface hotter and at higher latitudes hotter and at higher latitudes where sunlight is spread over a where sunlight is spread over a larger area the surface is cooler.larger area the surface is cooler.

6. 6. You decide not to be You decide not to be outside during the outside during the hottest hours of a hottest hours of a summer day. When summer day. When will the hottest hours will the hottest hours probably be? How do probably be? How do you know?you know?

• The hottest hours will probably be in The hottest hours will probably be in the late afternoon when Earth’s the late afternoon when Earth’s surface has had time to absorb and surface has had time to absorb and reradiate energy. This is also when reradiate energy. This is also when convection reaches its peak.convection reaches its peak.

““You should have seen the one that got You should have seen the one that got away”away”

• The End???The End???