Earths Atmosphere - PDF.pdf

Figure 6.31 At 12,200ft in the Ancient Bristlecone Pine Forest. The White Mountains, California. Image by Jeremy Patrich is used under a CC-BY 4.0 license. Goals & Objectives of this unit Understand the significance of the atmosphere. Describe the composition of the...

Figure 6.31 At 12,200ft in the Ancient Bristlecone Pine Forest. The White Mountains, California. Image by Jeremy Patrich is used under a CC-BY 4.0 license. Goals & Objectives of this unit Understand the significance of the atmosphere. Describe the composition of the atmospheric gasses. Explain the major layers of the atmosphere and their importance. Analyze the relationships between energy, temperature, and heat. budget and identify the values of albedo. Describe how heat is transferred around the planet. THE SIGNIFICANCE OF THE ATMOSPHERE s atmosphere is a thin blanket of gases and tiny particles called air. We are most aware of air when it moves and creates wind. All living things need some of the gases in the air for life support. Without an atmosphere, Earth would likely be just another is unique place in the solar system. Much of what makes Earth exceptional depends on the are lucky to have an atmosphere. 76 | P H Y S I C A L G E O G R A P H Y Indispensable for Life on Earth Without the atmosphere, Earth would look a lot more like the Moon. Atmospheric gases, especially carbon dioxide (CO2) and oxygen (O2) are extremely important for living organisms. How does the atmosphere make life possible? How does life alter the atmosphere? In photosynthesis, plants use CO2 and create O2. Photosynthesis is responsible for nearly all the oxygen currently found in the atmosphere. By creating oxygen and food, plants have made an environment that is favorable for animals. In respiration, animals use oxygen to convert sugar into food energy they can use. Plants also go through respiration and consume some of the sugars they produce. Along with the oceans, the atmosphere range. Greenhouse gases trap heat in the atmosphere so they help to moderate global temperatures. Without an atmosphere wit frigid at night and scorching during the day. Important greenhouse gases include carbon dioxide, methane, water vapor, and ozone. ATMOSPHERIC GASSES Nitrogen and oxygen together make up 99% of the plan are minor components but are sometimes very important. Humidity is the amount of water vapor in the air. Humidity varies from place to place and season to season. This fact is obvious if you compare a summer day in Atlanta, Georgia, where humidity is high, with a winter day in Phoenix, Arizona, where humidity is low. When the air is very humid, it feels heavy or sticky. Dry air usually feels more comfortable. Higher humidity is found around the equatorial regions because air temperatures are higher and warm air can hold more moisture than cooler air. Of course, humidity is lower near the Polar Regions because the air temperature is lower. Some of what are in the atmosphere is not gas. Particles of dust, soil, fecal matter, metals, salt, smoke, ash, and other solids make up a small percentage of the atmosphere. Particles provide starting points (or nuclei) for water vapor to condense on and form raindrops. 77 | P H Y S I C A L G E O G R A P H Y  Table 6.1 Showing Atmospheric Gasses as a Percent by Volume Gas Symbol Volume (%) Nitrogen 78.0840 Oxygen 20.9480 Argon A 0.9340 Carbon Dioxide 0.0314 Neon Ne 0.0018 Helium He 0.0005 Hydrogen