California science grade 5 (11)

CHAPTER Shaping Earth’s Surface What effects weathering, erosion, and deposition have on Earth’s landforms? 338 Lesson Atmospheric Pressure, Temperature, and Weather PAGE 342 Lesson Weathering, Erosion, and Deposition PAGE 356 Lesson Rivers and Streams PAGE 368 Lesson Beaches and Wave Erosion PAGE 380 Lesson Changing Habitats PAGE 390 ES Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment 339 Literature MAGAZINE ARTICLE ELA R 6.2.4 Clarify an understanding of texts by creating outlines, logical notes, summaries, or reports.• ELA W 6.2.5 Write persuasive compositions 340 from SCIENCE WORLD by Kim Y Masibay Surfing buffs have a word for the perfect wave— “tubular.” A wave curls into a tube and surfers ride inside it toward shore But the endless pounding of surf can really grind down a beach “About 86 percent of U.S shoreline is eroding [washing away],” says Chad Nelson, environmental director of the Surfrider Foundation The reasons are many: Damming rivers and building coastal structures cause some harm And the U.S Environmental Protection Agency thinks higher concentrations of greenhouse gases in the atmosphere [are] causing Earth’s temperature to warm, which in turn could raise sea level a few feet in the next century Bye-bye beaches? Not if geologists or engineers can help it But beach lovers are divided over how to best halt coastal erosion Why? Because tactics that keep sand where sunbathers want it can also wipe out the wave action in the surf zone, the area between the outermost breakers and the shore Can human ingenuity save the day? Write About It Response to Literature This article outlines the problem of beach erosion Geologists and engineers are working on solutions to the problem Do you think they should take the concerns of surfers or sunbathers into account? Write a persuasive essay explaining your point of view -Journal Write about it online @ www.macmillanmh.com 341 Lesson Atmospheric Pressure, Temperature, and Weather coastal fog, Mount Tamalpais State Park, California A television meteorologist wraps up the weather forecast: “Today was warm and humid Temperatures are expected to cool rapidly tonight, bringing fog during the early morning Skies will clear by mid-morning as temperatures rise again.” What causes fog? Where is fog likely to form? 342 ENGAGE ES 4.e Students know differences in pressure, heat, air movement, and humidity result in changes of weather Where does precipitation come from? Materials Form a Hypothesis When pressure is increased on a volume of air, its temperature increases When pressure is decreased, the volume of air expands and cools How temperature and humidity affect the formation of fog? Write your answer as a hypothesis in the form “If moist air in a bottle is cooled, then ” • room-temperature water Test Your Hypothesis Put a small amount of room-temperature water in a plastic water bottle Have your teacher add smoke by lighting a match, blowing it out, and holding the smoking match inside the bottle • plastic water bottle • match Step After a few seconds, have your teacher take the match out and screw on the bottle’s cap Experiment Squeeze the bottle to increase the pressure on the air inside Release the pressure on the bottle Draw Conclusions Analyze What happened when you released the pressure on the air in the bottle? How is this related to the temperature of the air in the bottle? Step Infer How does moist air’s temperature affect a change from water vapor to water droplets? How is this similar to the formation of fog? Explore More What would you see if you did this experiment first with warm water and then with cold water? Form hypotheses and then test them with your teacher or another adult Analyze and present your results IE 7.a Develop a hypothesis • IE 7.d Communicate the steps and results from an investigation in written reports and oral presentations 343 EXPLORE ▶ Main Idea ES 4.e Differences in air pressure and temperature cause winds, storms, and other weather patterns An area’s climate is the long-term average of its weather ▶ Vocabulary weather, p 344 humidity, p 345 dew point, p 348 Coriolis effect, p 350 eddy, p 352 -Glossary @ www.macmillanmh.com ▶ Reading Skill Make Inferences 1ZcSa EVObG]c 9\]e 7\TS`S\QSa Explore weather patterns with a meteorologist This satellite photo of Earth shows how the ocean temperatures around the world vary Yellow areas are the warmest 344 EXPLAIN What is the difference between climate and weather? An area’s climate (KLIGH•muht) is the long-term average weather pattern of that region It includes atmospheric conditions such as precipitation, temperature, and wind Many areas of the United States have climates with warm summers and cold winters Weather refers to the day-to-day conditions in an area Even though the climate in many states in the United States include hot summers, the weather on any single summer day may be cool Different Climates Climates vary by latitude (distance from the equator) and by altitude (height above sea level) An area closer to the equator receives more of the Sun’s heat, or radiation, than an area farther from the equator As a result the area near the equator has a warmer climate all year long For example, the southern United States has a warmer climate than the northern United States Winter temperatures in Southern California and Florida rarely fall below freezing, and snow rarely falls there Winter temperatures in North Dakota World Climates 3_cOb]` B`]^WQOZ 5SPQJDBM
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TVNNFS 4VCBSDUJD >]ZO` 5VOESB *DFDBQ 6WUVSZSdObW]\ Reading Maps )JHIMBOET and Montana, on the other hand, are often below freezing, and heavy snowfalls are frequent Altitude also affects climate The higher up you go on a mountain, the cooler you will find the temperature to be Even at the same latitude, a mountain peak may have snow in the spring and summer while a nearby valley is warm enough for swimming and other summer sports Radiation from the Sun first heats the land Then heat from Earth’s surface radiates into the atmosphere and warms it The thinner air at higher altitudes contains fewer molecules to absorb heat, so it remains cooler You may have noticed this change in temperature if you have traveled from the warm coast to the cooler inland mountains Changes in Weather Many factors make up daily weather, including temperature, air pressure, and humidity (hew•MID•i•tee) Describe the general locations of warm climates and cold climates Clue: Locate warm climates and cold climates on the map Humidity is the amount of water vapor in the air Precipitation, cloud cover, ocean temperature, and wind patterns also affect weather A change in any of these factors alters the daily weather in a particular location Weather conditions averaged over a long period of time determine climate Constant high temperatures and rain characterize tropical climates A place that is cold all year has a polar climate Quick Check Make Inferences Why is the climate in Alaska different from the climate in California? Critical Thinking What is the difference between climate and weather? 345 EXPLAIN What is air pressure? Air pressure is the force caused by the weight of air above Even though air molecules cannot be seen, they take up space and have weight Air pressure depends on temperature and gravity When the temperature rises, air molecules move apart This hotter, less dense air exerts less pressure When the temperature is cooler, air molecules slow down, and the cooler, denser air exerts more pressure The force of gravity attracts air particles and pulls them toward Earth, increasing the air pressure At higher altitudes, fewer air particles are attracted toward Earth, and air pressure falls If you take a trip to the top of a mountain, you may experience a “popping” in your ears The air pressure around you decreases as you climb the mountain Soon, the pressure inside your ear is no longer in balance with the pressure outside your ear The popping is your body’s attempt to equalize the pressure Also, during your trip up the mountain, you might notice that you have to breathe more rapidly to get enough oxygen as you climb Fewer molecules of oxygen exist at higher altitudes, so you have to take morerapid breaths to get the same number of molecules of oxygen into your lungs The table shows the change in air pressure with altitude For example, 4,418 m (14,495 ft) is the height of Mount Whitney, the highest point in the 48 adjoined United States, and about 80.5 km (100 mi) is considered by some to be the point at which space begins Air pressure is recorded in Pascals, a unit of measure that equals about 0.009 kg (0.02 pounds) per 0.09 square meter (0.96 square foot) =cbS`a^OQS &#Y[ Air Pressure and Altitude ;]c\bEVWb\Sg ""&Y[ AO\2WSU] Y[ 346 EXPLAIN Height Air Pressure (in kilometers) (in Pascals) 80.5 0.64 70 60 13 50 59 40 263 30 1,160 20 5,125 10 22,638 4.418 51,876 100,000 U.S Weather Map >]`bZO\R 6WUV :]e 2cZcbV ]`bZOR 6WUV :]e 2cZcbV