Earth’s Changing Atmosphere Chapter 15 Part 1 Life Support System
15.1 Earth’s Atmosphere Supports Life• Vocabulary— – Atmosphere – the layer of air that surrounds Earth – Altitude – distance above sea level – Density– the amount of mass in a given volume – Cycle– a process that repeats over and over• 1) Matter comes in three states. (Actually 4– don’t forget plasma!) Sketch an example of each.
How they change “states”http://3b4439.medialib.glogster.com/thumbnails/86/863d0af3bbd2e86937d9c8398149df66a7da9c152bc4358b5dcb489a36239bba/states-of-matter-source.jpg
The Atmosphere Makes Life onEarth Possible• 2) Write two ways that the atmosphere makes life possible on Earth. – Keeps Earth’s temperature even – Transports energy – Protects from excessive solar radiation• 3) Characteristics of the Atmosphere – Draw a picture of a mountain. Mark an X where the atmosphere’s density is greatest.
Earth’s Atmosphere That thin blue haze is the atmosphere
Materials in the Atmosphere• 4 Label the two most common gasses in the atmosphere and write the percentage of each. Oxygen 21% Nitrogen 78%
Natural Processes Modify theAtmosphere• 6) What is a cycle? – A Cycle is a process that repeats over and over.• 7) Look at the cycles shown in your textbook. How are all of the cycles alike? – Materials leave the air and return to the air over and over again.
More Ongoing Processes• 8) Fill in the chart to show three events that change the atmosphere suddenly. Name the event and the materials that get added to the atmosphere. Sudden changes affect atmosphere 1. Volcanic eruptions: gasses and ash 2. Forest Fires: carbon dioxide, ash 3. Dust storms: soil, microbes
Volcanic Activity• Mt. Pinatubo, 1991 That thin dark grey line is the layer of Pinatubo ash in the stratosphere. It affected weather on Earth for over 2 years until it settled out onto the surface. Layer of Pinatubo ash
Effects Worldwide• Each dip in temperature reflects the effect of a large volcanic ash eruption on worldwide temperatures As you can see, the temperature takes a couple years to return to normal after each eruption.
Fire Effects Satellite images of fires in Amazon
Dust Storms Affect all major cities in or near desert settings, even in Phoenix, AZ! Dust from the Sahara can travel and be found 5000 miles away in the Caribbean!
Dust Storms During the 1930’s in MidwestIn Melbourne, Australia, one ofAustralia’s largest cities.The dust gets through ANYhousehold opening. There is 0visibility in one.
15.2 The Sun Supplies theAtmosphere’s Energy• Vocabulary – Radiation = energy that moves across distances in the form of certain types of waves – Conduction = the moving of heat energy by one substance touching another – Convection = the moving of heat energy by the motion of a gas or liquid• 1) What are the two most plentiful gasses in Earth’s atmoshpere? – Nitrogen and oxygen
Energy from the Sun heats theatmosphere• 2) The circle graph shows the average amounts of solar radiation that are absorbed and reflected on Earth. Complete the graph by labeling its parts.
Atmosphere moves energy• 3) List 3 ways that energy is moved from place to place. – Radiation, conduction, convection
Radiation• 4) Earth’s surface becomes warmer when it is heated by radiation from the sun.
Conduction• 5) Explain why the bowl of the metal spoon gets hot after resting in a mug of very hot cocoa. – Energy is conducted from the hot liquid to the bowl of the metal spoon.
Convection • 6) Complete the diagram to show how convection works. Radiation from Sun heats ground Convection- the circulating motion of hot and cold. Warm ground heats up air and air becomes less dense Cool dense air sinksLess dense,warm air rises Conduction occurs where Ground air “touches” ground
Convection at work Hot material rises Cold material sinks
The atmosphere has temperature layers. • Label the following 2 lowest layers of the atmosphere.1) Stratosphere •Contains ozone •Temperature rises as move upward2) Troposphere •Contains almost all H2O vapor in atmosphere •Contains most mass of atmosphere •Heated by ground, temperature falls as move upward
Atmosphere’s TemperatureLayers• 8) Sometimes the tar of a newly paved road gets sticky on a very hot summer day. What causes this? – Dark road absorbs solar radiation enough so it heats up and starts to melt tar.
15.3 Gases in the AtmosphereAbsorb Radiation• Vocabulary – Ultraviolet radiation – waves that have more energy than visible light – Infrared radiation – waves that have less energy than visible light – Ozone– a molecule containing three atoms of oxygen – Greenhouse effect – the process by which gases absorb and give off infrared radiation, which keeps energy in Earth’s system for a while – Greenhouse gases – water vapor, carbon dioxide, methane, nitrous oxide, and other gases that absorb and give off infrared radiation• 1) What happens to solar radiation that reaches Earth? Some is reflected back into space while some is absorbed by Earth’s air, water, and land.
Gases can absorb and give offradiation• 2) List four ways that gases in the atmosphere can affect radiation. – Absorb radiation – Reflect radiation – Let it pass through – Emit radiation
Gases Can Absorb and Give OffRadiation (continued)• 3) Put descriptions of ultraviolet radiation and infrared radiation into the frame game diagram.• Ultraviolet radiation – like sound too high to hear, ozone absorbs it, shorter wavelength, has more energy than visible light• Infrared radiation– like sound too low to hear, longer wavelength, has less energy than visible light, greenhouse gases absorb and reflect this
The Ozone Layer Protects Life fromHarmful Radiation• Draw a picture to show the difference between a molecule of oxygen gas and a molecule of ozone. Ozone- O2 reflects UV Oxygen gas (breathable) O rays, but not 3 breathable
Ozone Layer• 5) List 3 ways that the ozone protects life on Earth. – Reduces sunburn and skin cancer – Reduces damage to eyesight – Prevents crop damage
The Greenhouse Effect KeepsEarth Warm• 6) Fill in the chart with facts about the ozone layer and greenhouse effect. Layer Gas(es) Type of radiation absorbed Ozone stratosphere ozone (O3) Ultraviolet layerGreenhous Troposphere Greenhouse Infrared radiation e effect gases (CO2 and CO)
The Greenhouse Effect (continued)• 7) What would happen on Earth if the atmosphere didn’t have greenhouse gases? – Infrared radiation would bounce off Earth’s surface into space leaving Earth’s average temperature at -18°C which is too cold for life dependant on liquid water.
15.4 Human Activities Affect the Atmosphere• Vocabulary – Air pollution – harmful materials that are added to the air – Particulate – any tiny particle or droplet of harmful material that is mixed in with air – Fossil fuel – fuel formed from the remains of once-living plants and animals – Smog – a combination of fog and smoke, or ozone and other pollutants produced by sunlight and gases• 1) What effect do greenhouse gases have on Earth? – Greenhouse gases absorb and emit infrared radiation that
Human activity can cause airpollution• 2) Suppose a factory in your town released harmful substances into the air. Is the effect of this air pollution limited to your town? Explain why or why not… – No! Air is fluid and will carry the pollution to other towns.
Types of Pollution• Gas Pollutants – CO – Methane – Ozone – Sulfur oxide• Particle Pollutants – Dust – Dirt – Pollen – Salt
Pollutants• 5) In cities, most air pollution comes from the burning of fossil fuels. Smoke from this burning can combine with water vapor in the air or fog to produce smog.
Effects of Pollution• 6) How does polluted air affect our health? – Examples: Irritates eyes, nose, throat and lungs. Causes allergies and breathing problems.
Controlling Pollution• 7) What are some things governments do to control pollution and its effects? – Smog and ozone laws to limit pollutants, laws to increase fuel efficiency.
Human activities are increasinggreenhouse gases.• 8) List three activities that can produce greenhouse gases. – CO2= burning of fossil fuels in cars, factories and power plants – Methane= cattle and livestock, landfills, and bacteria in rice fields – NO2= fertilizers and chemical factories
Global Warming• 9) What do you expect to happen if greenhouse gases such as carbon dioxide keep increasing? – Global temperatures will continue to rise. This can affect sources of food, water, and other resources available.
Reduction of GreenhouseGases• 10) List three benefits of reducing the amount of energy needed to heat buildings, transport people, and make products. – saves resources – Saves money – Reduces greenhouse gases and other pollutants
Human activities producechemicals that destroy the ozonelayer• 11) What happens when a chlorine atom enters the stratosphere? Why is this a bad thing? – It “steals” or takes an oxygen atom from ozone molecules and thus depletes the ozone layer. (With only 2 oxygen atoms, the molecule no longer protects us from ultraviolet radiation.)