Transcript Slide 1
Earth’s Atmosphere Take a Walk Through the Book • What looks interesting? • What are you looking forward to learning about? • What is something that you already know about? • Find a picture that looks interesting. Read the caption and write the page # down. 1.1 The Big Concept •Earth’s atmosphere is a blanket of gases that supports and protects life. Little Concepts • The atmosphere makes life on Earth possible. • Natural processes modify the atmosphere. Remember our 4 spheres • Atmosphere • Hydrosphere • Biosphere • Geosphere What is the Atmosphere? • Atmosphere: • Is a whole layer of air that surrounds Earth. Earth’s Atmosphere • Gases keep the Earth warm. • Transport energy to different regions of the planet. • Absorb and deflect radiation from the sun. Density • Density • The amount of mass in a given space. • Density is a key concept to our atmosphere. Altitude • The distance above sea level. • In 1862 two balloonists reached an altitude of 8.8Km (5.5 miles) • One passed out and one barely brought their balloon down. • They found that the air gets thinner as altitude increases. Altitude and Density • The higher up you go, the less air particles there are. • Where jets fly there is 1/10th the air molecules as at sea level. Where Does it End? • There is no real “end” to the atmosphere. (According to our book) • The gases just keep getting less and less dense as you move away from Earth. • At 500Km (300mi) you are considered in outer space. • 99% of the atmosphere’s mass is in the lowest 20 miles of the atmosphere. What is the Atmosphere Made up of? • • • • Gas Molecules Dust Sea Salt Water Molecules Gases in the Atmosphere • Put these gases in order from greatest to least and give them a percentage of how much of them are in our atmosphere: • Argon • Water Vapor • Oxygen • Other Elements • Nitrogen • Carbon Dioxide Which Gases? Gas Percent • Nitrogen • Oxygen • Argon • Carbon Dioxide • Other Elements • Water Vapor • 78.08 • 20.94 • 0.93 • 0.04 • 0.01 • 0-4* Natural Changes • Every day you breath in about 3,000 gallons of air. – About as much as it takes to fill a school bus. • Cycle: • A process that continues over and over. Three Important Cycles •Water Cycle •Nitrogen Cycle •Carbon Cycle The Water Cycle • The water cycle has three main phases. • Evaporation- water is heated and molecules rise up into the atmosphere. • Condensation- those same water molecules cool down and start to cling together. • Precipitation- As the water molecules cling together, they are too heavy for the air to hold and they fall back to Earth. The Water Cycle The Nitrogen Cycle • There are three main steps. • Animals remove nitrogen from the air and transform it into waste, that is deposited back to the soil. • Plants die and decay and the nitrogen in their system returns to the earth. • The soil slowly releases nitrogen gas back into the atmosphere. The Nitrogen Cycle The Carbon Cycle • Animals inhale oxygen and exhale carbon dioxide and water vapor. • Plants take in carbon dioxide and release oxygen. The Carbon Cycle Sudden Changes in Our Atmosphere • We can have sudden, natural events that change the composition of our atmosphere. • Volcanoes- The sulfur, carbon dioxide, and ash may cloud the air for long times. Sudden Changes in Our Atmosphere • Forest Fires- When trees burn, the carbon in them moves into the atmosphere. • Other Storms- Wind, water and drought can loosen soil. Wind storms add particles of dirt to the air. Bibliography • • • • • http://www.bing.com/images/search?q=Earth's+atmosphere&view=detail&id=C6717111B2EA4B2C406CE78629033CEBB6BA6A76 &first=1&FORM=IDFRIR http://wshm.bimedia.net/WebStuff/Air_vs._Altitude.jpg http://upload.wikimedia.org/wikipedia/commons/b/b1/Minnesota_population_map_cropped.png http://www.enchantedlearning.com/wgifs/Watercycle.GIF http://eo.ucar.edu/kids/green/images/carboncycle_sm.jpg