1. Table of Contents Energy in Earth’s Atmosphere Heat Transfer Winds
Water in the Atmosphere
Precipitation

2. Energy From the Sun - Energy in Earth’s Atmosphere
Most of the energy from the sun travels to Earth in the form of visible light and infrared radiation. A small amount arrives as ultraviolet radiation.

3. Energy in the Atmosphere
- Energy in Earth’s Atmosphere
Energy in the Atmosphere
Some sunlight is absorbed or reflected by the atmosphere. The rest passes through to the surface.

4. Greenhouse Effect - Energy in Earth’s Atmosphere
When Earth’s surface is heated, it radiates most of the energy back into the atmosphere as infrared radiation. Much of this energy is held by the atmosphere, warming it.

5. How Earth’s Atmosphere Gets Energy
- Energy in Earth’s Atmosphere
Sequencing
As you read, make a flowchart that shows how the sun’s energy reaches Earth’s surface.
How Earth’s Atmosphere Gets Energy
Sun gives off energy.
Energy travels to Earth as electromagnetic radiation.
Some of the sun’s energy is reflected back into space or absorbed by gases or particles in the air.
The remaining energy is absorbed or reflected by the surface.
Much of the energy absorbed by the surface is radiated back into the atmosphere.

6. Links on Energy in Earth’s Atmosphere
Click the SciLinks button for links on energy in Earth’s atmosphere.

7. End of Section: Energy in Earth’s Atmosphere

8. 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.

9. Converting Units - Heat Transfer
Temperatures in weather reports are usually given in Fahrenheit scale, but scientists use the Celsius scale. Temperature readings can be converted from the Fahrenheit scale to the Celsius scale using the following equation:
If the temperature is 68ºF, what is the temperature in degrees Celsius?
ºC = 20ºC

10. Converting Units - Heat Transfer Practice Problem
Use the equation to convert the following temperature from Fahrenheit to Celsius.
35.0ºF
1.67ºC

11. Converting Units - Heat Transfer Practice Problem
Use the equation to convert the following temperature from Fahrenheit to Celsius.
60.0ºF
15.6ºC

12. Converting Units - Heat Transfer Practice Problem
Use the equation to convert the following temperature from Fahrenheit to Celsius.
72.0ºF
22.2ºC

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

14. Outlining - Heat Transfer
As you read, make an outline about how heat is transferred. Use the red headings for the main topics and the blue headings for the subtopics.
Heat Transfer
Thermal Energy and Temperature
Measuring Temperature
Temperature Scales
How Heat Is Transferred
Radiation
Conduction
Convection
Heating the Troposphere

15. Click the SciLinks button for links on heat transfer.

16. Click the Video button to watch a movie about heat transfer.

17. End of Section: Heat Transfer

18. Angle of the Sun’s Rays - Winds
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.

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

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

21. Global Winds Activity - Winds
Click the Active Art button to open a browser window and access Active Art about global winds.

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

23. 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.

24. Click the Video button to watch a movie about convection currents.
- Winds
Convection Currents
Click the Video button to watch a movie about convection currents.

25. End of Section: Winds

26. Water Cycle Activity - Water in the Atmosphere
Click the Active Art button to open a browser window and access Active Art about the water cycle.

27. Determining Relative Humidity
- Water in the Atmosphere
Determining Relative Humidity
Relative humidity is affected by temperature. Use the data table to answer the following questions. First, find the dry-bulb temperature in the left column of the table. Then find the difference between the wet- and dry-bulb temperatures across the top of the table. The number in the table where these two readings intersect indicates the relative humidity in percent.

28. Determining Relative Humidity
- Water in the Atmosphere
Determining Relative Humidity
Interpreting Data:
At noon, the reading on a sling psychrometer are 18ºC for the dry-bulb thermometer and 14ºC for the wet-bulb thermometer. What is the relative humidity?
64%

29. Determining Relative Humidity
- Water in the Atmosphere
Determining Relative Humidity
Interpreting Data:
At 5 p.m., the psychrometer is used again. The reading on the dry-bulb thermometer is 12ºC and the reading on the wet-bulb thermometer is 11ºC. Determine the new relative humidity.
88%

30. Determining Relative Humidity
- Water in the Atmosphere
Determining Relative Humidity
Interpreting Data:
How did the temperature change between noon and 5 P.M.?
It decreased from 18 degrees to 12 degrees.

31. Determining Relative Humidity
- Water in the Atmosphere
Determining Relative Humidity
Interpreting Data:
How did the relative humidity change during the course of the day?
It increased.

32. Determining Relative Humidity
- Water in the Atmosphere
Determining Relative Humidity
Drawing Conclusions:
How was the relative humidity affected by air temperature? Explain your answer.
For the same amount of water in the air, as the temperature decreases, the relative humidity increases. Warm air can hold more moisture than cool air can.

33. How Clouds Form - Water in the Atmosphere
Clouds form when warm, moist air rises and cools. Water vapor condenses on tiny particles to form liquid water or ice crystals.

34. Types of Clouds - Water in the Atmosphere
Scientists classify clouds into three main types based on their shape: cirrus, cumulus, and stratus. Clouds are further classified by their altitude.

35. Asking Questions - Water in the Atmosphere
Before you read, preview the red headings. In a graphic organizer like the one below, ask a what or how question for each heading. As you read, write answers to your questions.
Question
Answer
How does the water cycle work?
Water evaporates from the surface, condenses to form clouds, and falls to Earth as rain or snow.
What is relative humidity?
The percentage of water vapor in the air compared to the maximum amount air can hold at that temperature
How do clouds form?
Water in the air condenses on tiny particles in the air to form liquid water or crystals.
Can you determine weather conditions by looking at clouds?
Yes; each type of cloud is associated with a particular type of weather.

36. End of Section: Water in the Atmosphere

37. Water Droplets - Precipitation
Droplets come in many sizes. A raindrop has about one million times as much water in it as a cloud droplet.

38. How Hail Forms - Precipitation
Hailstones start as small pellets of ice in cumulonimbus clouds. They grow larger as they are repeatedly tossed up and down until they become so heavy they fall to the ground.

39. Measuring Precipitation
Scientists measure precipitation with various instruments, including rain gauges.

40. Using Prior Knowledge - Precipitation
Before you read, look at the section headings and visuals to see what this section is about. Then write what you know about precipitation in a graphic organizer like the one below. As you read, write what you learn.
What You Know
Precipitation can be rain or snow.
Precipitation comes from clouds.
What You Learned
Sleet, freezing rain, and hail are forms of precipitation.
Droplets or ice crystals in clouds must grow heavy enough to fall through the air before precipitation occurs.

41. Links on Precipitation
Click the SciLinks button for links on precipitation.

42. End of Section: Precipitation

43. Prevailing westerlies
Graphic Organizer
include
two types
three types
Earth’s winds
Local winds
Trade winds
Global winds
Prevailing westerlies
Polar easterlies
Sea breeze
Land breeze

44. End of Section: Graphic Organizer