Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
ES-11.1: The Air Around You (Key Concept Summaries) Describe the composition of Earth’s atmosphere and give an example of how events in one part affect other parts of the atmosphere. ES-11.1: The Air Around You (Enrichment) Earth’s atmosphere once contained almost no oxygen, but as the planet changed, so did the atmosphere. Read the following passage. Then answer the questions that follow on a separate sheet of paper. How Earth’s Atmosphere Got Its Oxygen When Earth’s atmosphere first formed, it contained little, if any, oxygen. How, then, did our oxygenrich atmosphere come about? The answer is life, which first appeared in the form of bacteria about 3.5 billion years ago. By about 2.5 billion years ago, oxygen-producing organisms, called cyanobacteria, had evolved. Evolution is the process by which organisms change to give rise to new organisms over time. The cyanobacteria took in carbon dioxide and water and produced oxygen as a waste product. Over time, the oxygen they produced accumulated in the atmosphere. Some of this oxygen was converted to ozone by the sun’s energy. This was important later for the development of life on land because as ozone increased, it protected Earth’s surface from too much ultraviolet radiation. By 700 million years ago, the oxygen concentration had reached about ten percent of the current level, and organisms made up of many cells had evolved. By 450 million years ago, the ozone level was getting close to its present value. Soon after that land plants evolved. Land animals followed about 380 million years ago. Both oxygen and ozone reached their current levels about 300 million years ago. By then there were many different kinds of complex land plants and animals living on Earth. 1. How did life influence the development of Earth’s atmosphere? 2. What role did ozone play in the evolution of life on Earth? 3. What do you think Earth’s atmosphere would be like today if life had not evolved on Earth? ES-11.2: Air Pressure (Key Concept Summaries) Explain what air density and air pressure are, and how altitude affects these properties of air. ES-11.2: Air Pressure (Enrichment) Weather maps have special lines that show different areas of air pressure. Read the passage and examine the map. Refer to the map to complete the statements below. Isobars and Air Pressure Air pressure is an important factor affecting weather. Changes in air pressure help weather forecasters predict how the weather will change. Falling air pressure usually indicates stormy weather. Rising air pressure means that the weather is clearing. Air pressure readings from barometers are shown on weather maps, like the one below, with lines called isobars. Isobars are drawn to connect areas that have the same air pressure. 1. Each isobar differs from the next isobar by miillibars. 2. The lowest air pressure reading shown is millibars. 3. Where this low pressure occurs, the weather is likely to be . 4. The highest air pressure reading shown is millibars. 5. This high-pressure area is likely to be experiencing weather. 6. An area of air pressure is centered northwest of Chicago. ES-11.3: Layers of the Atmosphere(Key Concept Summaries) Describe the characteristics of the four main layers of the atmosphere. ES-11.3: Layers of the Atmosphere (Enrichment) Earth’s weather occurs in the troposphere, and air pressure is an important factor in weather. Use the data on air pressure in the table to make a graph showing how air pressure changes as you move upward in the troposphere. Then answer the questions below on a separate sheet of paper. Air Pressure in the Troposphere Altitude (m above sea level) 0 (sea level) Average Air Pressure Altitude (m above sea level) Average Air Pressure 1013.2 5,500 505.4 500 954.6 6,000 472.2 1,000 898.8 6,500 440.8 1,500 845.6 7,000 411.0 2,000 795.0 7,500 383.0 2,500 746.9 8,000 356.5 3,000 701.2 8,500 331.5 3,500 657.8 9,000 308.0 4,000 616.6 9,500 285.8 4,500 577.5 10,000 265.0 5,000 540.5 1. Describe the relationship between altitude and air pressure shown in the graph. 2. Estimate the average air pressure in a hole 500 meters below sea level. 3. If you were flying in a plane at an altitude of 1,500 meters, what would the air pressure outside the plane be? When you fly that high, why might your ears “pop”? ES-11.4: Energy in Earth’s Atmosphere (Key Concept Summaries) Briefly explain how energy from the sun travels to Earth and describe what happens to this energy as it passes through the atmosphere. ES-11.4: Energy in Earth’s Atmosphere (Enrichment) Read the following passage and examine the figure. Then use the figure to answer the questions below on a separate sheet of paper. Reflection of Solar Radiation On average, about half of the sunlight that strikes Earth’s atmosphere reaches the surface of the planet to be absorbed and converted to heat. This absorbed light is a key factor in determining Earth’s temperature and weather. Also it is crucial for the normal functioning of Earth’s greenhouse effect. The other half of the sunlight that strikes the Earth’s atmosphere is either absorbed by the atmosphere or reflected back into space by clouds or by Earth’s surface itself. The amount of sunlight that is reflected back into space in a particular place depends mainly on how thick the clouds are and whether Earth’s surface is dark or light. The figure below shows how much energy is reflected back into space with different thicknesses of cloud cover and different types of surface on Earth. 1. Which two types of surface on Earth are most important for absorbing solar energy and keeping the planet warm? Explain your answer. 2. Why do skiers often get sunburned even in the winter, when the sun’s rays are not very strong? 3. What effect would thick cloud cover have on the temperature of Earth’s surface? Explain. 4. Why might a major volcanic eruption lead to cooler temperatures over a large area around a volcano? 5. Which do you think would be warmer on a winter day when there is no wind, a thick forest or a grassy field? Explain your answer. ES-11.5: Heat Transfer(Key Concept Summaries) Explain how energy from the sun becomes thermal energy on Earth and how that energy raises the temperature of the troposphere. ES-11.5: Heat Transfer (Enrichment) Read the following passage and examine the figure. Then answer the questions below on a separate sheet of paper. Heat and Human Health Extremely hot weather can be dangerous to human health. During a heat wave, the body struggles to maintain a healthy temperature of about 37°C. Heat stress may set in before the air temperature exceeds this mark, however, because the body also produces heat when it does work. The figure shows how the brain and body respond to excessive heat. The additional stress this response places on the heart and blood vessels can trigger heart and other medical problems, especially in the elderly. Because of this, death rates often rise when a heat wave strikes. 1. The brain detects when the body is too warm and stimulates other body parts to respond. 3. Sweating increases and evaporation of the sweat helps cool the body’s surface. 2. Blood vessels expand and the heart beats faster to increase blood flow to the body’s surface. 4. The body becomes dehydrated if the fluid lost in sweat is not replaced. 1. Heat can be lost from the body in the same ways that heat is lost from Earth’s surface. Based on what you know about heat transfer from Earth’s surface to the atmosphere, describe how the body can lose heat in each of these ways. 2. The body also loses heat by the evaporation of sweat. How is a tea kettle boiling similar to the evaporation of sweat from the body? 3. Why are you more likely to become dehydrated in hot weather? ES-11.6: Winds(Key Concept Summaries) Describe what causes winds to form and explain how local winds and global winds differ. ES-11.6: Winds (Enrichment) In cities, large buildings and other obstacles can change the direction of the wind and make it difficult to tell from which direction the wind is blowing. To get the true direction of the wind over a city, it is better to observe how the clouds are moving. You can make a simple device, called a nephoscope, to track cloud movement. Follow the directions given. Then answer the questions below on a separate sheet of paper. Using Clouds to Measure the Wind With a large mirror and a grease pencil or marker that will write on glass, go outside in an open area on a day with some wind and clouds. Place the mirror face up on the ground. (CAUTION: Handle the mirror carefully so it does not break.) Use a compass to determine the four directions and mark them on the four sides of the mirror. Now your nephoscope is ready to use. To measure cloud direction, watch the mirror for cloud reflections to appear. Put an X in the reflection of a cloud as it appears on the edge of the mirror. As the reflection of the cloud moves across the mirror, plot its course by putting more Xs along its path. After the cloud’s reflection has passed across the mirror, join the Xs with a line and use the line to determine the overall direction of the cloud. 1. What wind direction did your nephoscope indicate? How does that direction compare with the direction based on on-the-ground indicators, such as wind vanes, flags flying, or smoke drifting? If the directions are different, what do you think is the reason? 2. Why is a nephoscope a more accurate indicator of wind direction over a city than a wind vane on the ground? 3. Can you think of any disadvantage in depending on a nephoscope to measure wind direction?