1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu LECTURE The pictures in this PowerPoint presentation are hyperlinked to a video

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Composition of the Atmosphere atmosphere a mixture of gases that surrounds a planet, such as Earth. The most abundant elements in air are the gases nitrogen (78%), oxygen (21%), and argon. The two most abundant compounds in air are the gases carbon dioxide, CO 2, and water vapor, H 2 O. In addition to containing gaseous elements and compounds, the atmosphere commonly carries various kinds of tiny solid particles, such as dust and pollen.

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Atmospheric Pressure atmospheric pressure the force per unit area that is exerted on a surface by the weight of the atmosphere. Gravity holds the gases of the atmosphere near Earth’s surface. As a result, the air molecules are compressed together and exert force on Earth’s surface. Atmospheric pressure is exerted equally in all directions—up, down, and sideways. Meteorologists measure atmospheric pressure by using an instrument called a barometer.

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Atmospheric Pressure, continued Earth’s gravity keeps 99% of the total mass of the atmosphere within 32 km of Earth’s surface (upper part of Stratosphere). Because the pull of gravity is not as strong at higher altitudes, the air molecules are farther apart and exert less pressure on each other at higher altitudes. Thus, atmospheric pressure decreases as altitude increases.

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Atmospheric Pressure, continued Atmospheric pressure also changes as a result of differences in temperature and in the amount of water vapor in the air. In general, as temperature increases, atmospheric pressure at sea level decreases. Similarly, air that contains a lot of water vapor is less dense than drier air because water vapor molecules have less mass than nitrogen or oxygen molecules do.

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere The Troposphere troposphere the lowest layer of the atmosphere, in which temperature drops at a constant rate as altitude increases; the part of the atmosphere where weather conditions exist. At an average altitude of 12 km, the temperature stops decreasing. This zone is called the tropopause and represents the upper boundary of the troposphere.

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere, continued The Stratosphere stratosphere the layer of the atmosphere that lies between the troposphere and the mesosphere and in which temperature increases as altitude increases; contains the ozone layer. In the upper stratosphere, the temperature increases as altitude increases because air in the stratosphere is heated from above by absorption of solar radiation by ozone.

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere, continued The Mesosphere mesosphere the coldest layer of the atmosphere, between the stratosphere and the thermosphere, in which the temperature decreases as altitude increases. The upper boundary of the mesosphere, called the mesopause, has an average temperature of nearly  90°C, which is the coldest temperature in the atmosphere.

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere, continued The Thermosphere thermosphere the uppermost layer of the atmosphere, in which temperature increase as altitude increases; includes the ionosphere. There are not enough data about temperature changes in the thermosphere to determine its upper boundary. However, above the ionosphere is the region where Earth’s atmosphere blends into the almost complete vacuum of space.

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere, continued Page 552

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere, continued Page 552

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere, continued Page 552

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere, continued Page 552

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Layers of the Atmosphere, continued Page 552

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Temperature Inversions Any substance in the atmosphere and that is harmful to people, animals, plants, or property is called an air pollutant. Today, the main source of air pollution is the burning of fossil fuels, such as coal and petroleum. Certain weather conditions can make air pollution worse. One such condition is a temperature inversion, the layer of warm air on top of cool air.

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter 22 Temperature Inversions, continued In some areas, topography may make air pollution even worse by keeping the polluted inversion layer from dispersing. Under conditions in which air cannot circulate up and away from an area, trapped automobile exhaust can produce smog, a general term for air pollution that indicates a combination of smoke and fog.

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Solar Energy and the Atmosphere Chapter 22 Radiation electromagnetic spectrum all of the frequencies or wavelengths of electromagnetic radiation. All of the energy that Earth receives from the sun travels through space between Earth and the sun as radiation. Radiation includes all forms of energy that travel through space as waves.

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Solar Energy and the Atmosphere Chapter 22 Radiation, continued The diagram below shows the the waves of the electromagnetic spectrum. Long waveShort wave Page 555

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Solar Energy and the Atmosphere Chapter 22 Absorption and Infrared Energy, continued The Greenhouse Effect greenhouse effect the warming of the surface and lower atmosphere of Earth that occurs when carbon dioxide, water vapor, and other gases in the air absorb and reradiate radiation. Earth’s atmosphere slows the escape of energy that radiates from Earth’s surface.

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Solar Energy and the Atmosphere Chapter 22 Absorption and Infrared Energy, continued Human Impact on the Greenhouse Effect Generally, the amount of solar energy that enters Earth’s atmosphere is about equal to the amount that escapes into space. However, human activities may change this balance and may cause the average temperature of the atmosphere to increase. Increases in the amount of carbon dioxide may intensify the greenhouse effect and may cause Earth to become warmer in some areas and cooler in others.

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Solar Energy and the Atmosphere Chapter 22 Absorption and Infrared Energy, continued Page 558

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Solar Energy and the Atmosphere Chapter 22 Conduction conduction the transfer of energy as heat through a material. The molecules in a substance move faster as they become heated. Collisions between the particles result in the transfer of energy, which warms the substance. Thus, conduction heats only the lowest few centimeters of the atmosphere, where air comes into direct contact with the warmed surface of Earth.

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Solar Energy and the Atmosphere Chapter 22 Convection convection the movement of matter due to differences in density that are caused by temperature variations; can result in the transfer of energy as heat. Convection occurs when gases or liquids are heated unevenly. The continuous cycle in which cold air sinks and warm air rises warms Earth’s atmosphere evenly.

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 The Coriolis Effect Coriolis effect the curving of the path of a moving object from an otherwise straight path due to Earth’s rotation. Winds that blow from high pressure areas to lower- pressure areas curve as a result of the Coriolis effect. In general, the Coriolis effect is detectable only on objects that move very fast or that travel over long distances.

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 The Coriolis Effect, continued Page 561

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Global Winds Each hemisphere contains three looping patterns of flow called convection cells. Each convection cell correlates to an area of Earth’s surface, called a wind belt, that is characterized by winds that flow in one direction. These winds are called prevailing winds.

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Global winds, continued Trade Winds trade wind prevailing winds that blow from east to west from 30º latitude to the equator in both hemispheres. Like all winds, trade winds are named according to the direction from which they flow. In the Northern Hemisphere, the trade winds flow from the northeast and are called the northeast trade winds. In the Southern Hemisphere, they are the southeast trade winds.

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Global Winds, continued Westerlies westerlies prevailing winds that blow from west to east between 30º and 60º latitude in both hemispheres. Between 30º and 60º latitude, some of the descending air moving toward the poles is deflected by the Coriolis effect. In the Northern Hemisphere, the westerlies are the southwest winds. In the Southern Hemisphere, they are the northwest winds.

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Global Winds, continued Polar Easterlies polar easterlies prevailing winds that blow from east to west between 60 and 90 latitude in both hemispheres. Surface winds created by the polar high pressure are deflected by the Coriolis effect and become the polar easterlies. Where the polar easterlies meet warm air from the westerlies, a stormy region known as a front forms.

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Global Winds, continued The Doldrums and Horse Latitudes The trade wind systems of the Northern Hemisphere and Southern Hemisphere meet at the equator in a narrow zone called the doldrums. As the air approaches 30º latitude, it descends and a high-pressure zone forms. These subtropical high- pressure zones are called horse latitudes.

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Global Winds, continued Jet Streams jet streams a narrow band of strong winds that blow in the upper troposphere. These winds exist in the Northern and Southern Hemisphere. One type of jet stream is a polar jet stream. Polar jet streams can reach speeds of 500 km/h and can affect airline routes and the paths of storms.

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Global Winds, continued Page 562 Extra Credit Listen for it…

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Local Winds Movement of air are also influenced by local conditions, and local temperature variations commonly cause local winds. Local winds are not part of the global wind belts. Gentle winds that extend over distances of less than 100 km (approx. 60 miles) are called a breeze.

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Local Winds, continued Land and Sea Breezes Equal areas of land and water may receive the same amount of energy from the sun. However, land surfaces heat up faster than water surfaces do. The cool wind moving from water to land is called a sea breeze. Overnight, the land cools more rapidly than water does, and the sea breeze is replaced by a land breeze.

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Atmospheric Circulation Chapter 22 Local Winds, continued Mountain and Valley Breezes A valley breeze forms when warm air from the valleys moves upslope. At night, the mountains cool more quickly than the valleys do. At that time, cool air descends from the mountain peaks to create a mountain breeze. Areas near mountains may experience a warm afternoon that turns to a cold evening soon after sunset.

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice 1.Which of the following processes is the source of the oxygen gas found in Earth’s atmosphere? A.oxidation B.combustion C.respiration D.photosynthesis Standardized Test Prep Chapter 22

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 1.Which of the following processes is the source of the oxygen gas found in Earth’s atmosphere? A.oxidation B.combustion C.respiration D.photosynthesis Standardized Test Prep Chapter 22

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 2.Which of the following statements best describes the relationship of atmospheric pressure to altitude. F.The atmospheric pressure increases as the altitude increases. G.The atmospheric pressure increases as the altitude decreases. H.The atmospheric pressure varies unpredictably at different altitude. I.The atmospheric pressure is constant at all altitudes. Standardized Test Prep Chapter 22

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 2.Which of the following statements best describes the relationship of atmospheric pressure to altitude. F.The atmospheric pressure increases as the altitude increases. G.The atmospheric pressure increases as the altitude decreases. H.The atmospheric pressure varies unpredictably at different altitude. I.The atmospheric pressure is constant at all altitudes. Standardized Test Prep Chapter 22

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 3.Approximately how much of the solar energy that reaches Earth is absorbed by the atmosphere, land surfaces, and ocean? A.30% B.50% C.70% D.100% Standardized Test Prep Chapter 22

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 3.Approximately how much of the solar energy that reaches Earth is absorbed by the atmosphere, land surfaces, and ocean? A.30% B.50% C.70% D.100% Standardized Test Prep Chapter 22

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 4.In the Northern Hemisphere, the Coriolis effect causes winds moving toward the North Pole to be deflected in which of the following ways? F.Winds are deflected to the right. G.Winds are deflected to the left. H.Winds are deflected in unpredictable patterns. I.Winds are not deflected by the Coriolis effect. Standardized Test Prep Chapter 22

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 4.In the Northern Hemisphere, the Coriolis effect causes winds moving toward the North Pole to be deflected in which of the following ways? F.Winds are deflected to the right. G.Winds are deflected to the left. H.Winds are deflected in unpredictable patterns. I.Winds are not deflected by the Coriolis effect. Standardized Test Prep Chapter 22

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 5.What is the most abundant gas in Earth’s atmosphere? Standardized Test Prep Chapter 22

45. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 5.What is the most abundant gas in Earth’s atmosphere? nitrogen Standardized Test Prep Chapter 22

46. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 6.In which atmospheric layer do interactions between gas molecules and solar radiation produce the aurora borealis phenomenon? Standardized Test Prep Chapter 22

47. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 6.In which atmospheric layer do interactions between gas molecules and solar radiation produce the aurora borealis phenomenon? troposphere Standardized Test Prep Chapter 22

48. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Skills Read the passage below. Then, answer questions 7-9. The Snow Eater The chinook, or “snow eater,” is a dry wind that blows down the eastern side of the Rocky Mountains from New Mexico to Alaska. Arapaho gave the chinook its name because of its ability to melt large amounts of snow very quickly. Chinooks form when moist air is forced over a mountain range. The air cools as it rises. As the air cools, it releases moisture in the form of rain or snow, which nourishes the local flora. As the dry air flows over the mountaintop, they air compresses and heats the air below. The warm, dry wind that results can melt half of a meter of snow in just a few hours. The temperature change caused when a chinook rushes down a mountainside can be dramatic. In 1943, in Spearfish, South Dakota, the temperature at 7:30 A.M. was -4ºF. But only two minutes later, a chinook caused the temperature to soar to 45ºF. Standardized Test Prep Chapter 22

49. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Skills, continued 7.Why are the chinook winds of the Rocky Mountains called “snow eaters?” A.Chinook winds pick up snow and carry it to new locations. B.Chinook winds drop all of their snow on the western side of the mountains. C.Chinook winds cause the temperature to decrease, which causes snow to accumulate. D.Chinook winds cause the temperature to increase rapidly, which causes snow to melt. Standardized Test Prep Chapter 22

50. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Skills, continued 7.Why are the chinook winds of the Rocky Mountains called “snow eaters?” A.Chinook winds pick up snow and carry it to new locations. B.Chinook winds drop all of their snow on the western side of the mountains. C.Chinook winds cause the temperature to decrease, which causes snow to accumulate. D.Chinook winds cause the temperature to increase rapidly, which causes snow to melt. Standardized Test Prep Chapter 22

51. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Skills, continued 8.Which of the following statements can be inferred from the information in the passage? F.Chinook winds are a relatively new phenomenon related to global warming. G.The Rocky Mountains are more arid on their eastern side than on their western side. H.The only type of wind that blows down from mountaintops are chinook winds. I.When they blow up the western side of the Rocky Mountains, chinook winds are very hot. Standardized Test Prep Chapter 22

52. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Skills, continued 8.Which of the following statements can be inferred from the information in the passage? F.Chinook winds are a relatively new phenomenon related to global warming. G.The Rocky Mountains are more arid on their eastern side than on their western side. H.The only type of wind that blows down from mountaintops are chinook winds. I.When they blow up the western side of the Rocky Mountains, chinook winds are very hot. Standardized Test Prep Chapter 22

53. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Skills, continued 9.How might chinook winds affect agriculture on the eastern side of the Rocky Mountains? Standardized Test Prep Chapter 22

54. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Skills, continued 9.How might chinook winds affect agriculture on the eastern side of the Rocky Mountains? Answers should include the following: chinook winds affect human beings and agriculture in a number of ways; while the winds have a definite benefit in reducing exposure to the cold, some of their other effects may be less beneficial; chinook winds are hot and arid, which lowers local humidity levels and removes moisture from the soil; in the summer, the hot winds are especially destructive to small and non-native crops; the sudden changes in temperature may also make animals more susceptible to disease; in the winter months, chinook winds remove snow cover and make grazing easier for animals; but in the summer the winds may harm suitable grazing lands. Standardized Test Prep Chapter 22

55. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics Use the diagram below to answer questions 10 through 11. The diagram shows global wind belts and convection cells at different latitudes. Standardized Test Prep Chapter 22

56. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics, continued 10.What happens to the air around location A as the air warms and decreases in density? A.It rises. B.It sinks. C.It stagnates. D.It contracts. Standardized Test Prep Chapter 22

57. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics, continued 10.What happens to the air around location A as the air warms and decreases in density? A.It rises. B.It sinks. C.It stagnates. D.It contracts. Standardized Test Prep Chapter 22

58. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics, continued 11.Compare and contrast wind patterns in the global wind belts labeled C and D. why do the winds move in the directions shown? Standardized Test Prep Chapter 22

59. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics, continued 11.Compare and contrast wind patterns in the global wind belts labeled C and D. why do the winds move in the directions shown? Location C has northeast winds. Location D has southeast winds. Cool air flows toward low pressure caused by rising warm air near the equator. Both winds are somewhat easterly because of Earth’s rotation. Standardized Test Prep Chapter 22

60. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics, continued Use the graphic below to answer question 12. The graphic shows a typical coastal area. Standardized Test Prep Chapter 22

61. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics, continued 12.Would the direction of local winds be the same during the night as they would during the day in this location? Explain your answer in terms of the wind’s direction and cause during the day and during the night. Standardized Test Prep Chapter 22

62. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics, continued 12.Would the direction of local winds be the same during the night as they would during the day in this location? Explain your answer in terms of the wind’s direction and cause during the day and during the night. Answer should include: the wind directions of local winds would be different at this location during the night from those during the day; the sun will heat land and water at different rates; temperature and density differences will exist in the air masses above the land and the water; during the day, solar radiation will heat the land faster than it will heat the ocean, producing a wind that moves from the ocean to the land as warm land air rises; just as land warms quicker during the day than water, land cools more quickly at night than ocean water does; at night, cool air from the land moves seaward as warmer ocean air rises. Standardized Test Prep Chapter 22