Earth’s Changing Earth’s Changing AtmosphereAtmosphere

Chapter 15Chapter 15

Part 1 Life Support SystemPart 1 Life Support System

15.1 Earth’s Atmosphere 15.1 Earth’s Atmosphere Supports LifeSupports Life

• Vocabulary—Vocabulary—– AtmosphereAtmosphere– the layer of air that surrounds – the layer of air that surrounds

EarthEarth– AltitudeAltitude– distance above sea level– distance above sea level– Density–Density– the amount of mass in a given volume the amount of mass in a given volume– Cycle–Cycle– a process that repeats over and over a process that repeats over and over

• 1) Matter comes in three states. 1) Matter comes in three states. (Actually 4– don’t forget plasma!) (Actually 4– don’t forget plasma!) Sketch an example of each.Sketch an example of each.

States of matterStates of matter

And don’t forget PLASMA!!!And don’t forget PLASMA!!!

How they change “states”How they change “states”

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The Atmosphere Makes Life on The Atmosphere Makes Life on Earth PossibleEarth Possible

• 2) Write two ways that the atmosphere 2) Write two ways that the atmosphere makes life possible on Earth.makes life possible on Earth.– Keeps Earth’s temperature evenKeeps Earth’s temperature even– Transports energyTransports energy– Protects from excessive solar radiationProtects from excessive solar radiation

• 3) Characteristics of the Atmosphere3) Characteristics of the Atmosphere– Draw a picture of a mountain. Mark an X Draw a picture of a mountain. Mark an X

where the atmosphere’s density is where the atmosphere’s density is greatest.greatest.

Earth’s AtmosphereEarth’s AtmosphereThat thin blue haze is the atmosphere

Materials in the AtmosphereMaterials in the Atmosphere• 4 Label the two most common gasses in the 4 Label the two most common gasses in the

atmosphere and write the percentage of each.atmosphere and write the percentage of each.

• 5) What else is in the atmosphere besides gases?5) What else is in the atmosphere besides gases?– Tiny particles of solids such as dust, sea salt, also water Tiny particles of solids such as dust, sea salt, also water

dropletsdroplets..

Oxygen

21%

Nitrogen

78%

Natural Processes Modify the Natural Processes Modify the AtmosphereAtmosphere

• 6) What is a cycle?6) What is a cycle?– A Cycle is a process that repeats over A Cycle is a process that repeats over

and over.and over.

• 7) Look at the cycles shown in your 7) Look at the cycles shown in your textbook. How are all of the cycles textbook. How are all of the cycles alike?alike?– Materials leave the air and return to the Materials leave the air and return to the

air over and over again.air over and over again.

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More Ongoing ProcessesMore Ongoing Processes

• 8) 8) Fill in the chart to show three events that Fill in the chart to show three events that change the atmosphere suddenly. Name the change the atmosphere suddenly. Name the event and the materials that get added to the event and the materials that get added to the atmosphere.atmosphere.

Sudden changes affect atmosphere

1. Volcanic eruptions: gasses and ash

2. Forest Fires: carbon dioxide, ash

3. Dust storms: soil, microbes

Other sources Other sources of greenhouse of greenhouse gasesgases• VolcanoesVolcanoes

• Forest FiresForest Fires

• Dust StormsDust Storms

Effects of Volcano on Effects of Volcano on AtmosphereAtmosphere

Volcanic ActivityVolcanic Activity

• Mt. Pinatubo, 1991Mt. 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 WorldwideEffects Worldwide• Each dip in Each dip in

temperature reflects temperature reflects the effect of a large the effect of a large volcanic ash eruption volcanic ash eruption on worldwide on worldwide temperaturestemperatures

As you can see, the temperature takes a couple years to return to normal after each eruption.

Fire EffectsFire EffectsSatellite images of fires in Amazon

Dust StormsDust Storms

Dust from the Sahara can travel and be found 5000 miles away in the Caribbean!

Affect all major cities in or near desert settings, even in Phoenix, AZ!

Dust StormsDust StormsDuring the 1930’s in Midwest

In Melbourne, Australia, one of Australia’s largest cities.The dust gets through ANY household opening. There is 0 visibility in one.

15.2 The Sun Supplies the 15.2 The Sun Supplies the Atmosphere’s EnergyAtmosphere’s Energy

• VocabularyVocabulary– RadiationRadiation= energy that moves across = energy that moves across

distances in the form of certain types of wavesdistances in the form of certain types of waves– ConductionConduction= the moving of heat energy by = the moving of heat energy by

one substance touching anotherone substance touching another– ConvectionConvection= the moving of heat energy by = the moving of heat energy by

the motion of a gas or liquidthe motion of a gas or liquid• 1) What are the two most plentiful gasses in 1) What are the two most plentiful gasses in

Earth’s atmoshpere?Earth’s atmoshpere?– Nitrogen and oxygenNitrogen and oxygen

Energy from the Sun heats the Energy from the Sun heats the atmosphereatmosphere• 2) The circle graph shows the average amounts of 2) The circle graph shows the average amounts of

solar radiation that are absorbed and reflected on solar radiation that are absorbed and reflected on Earth. Complete the graph by labeling its parts. Earth. Complete the graph by labeling its parts.

The specificsThe specifics

Atmosphere moves energyAtmosphere moves energy

• 3) List 3 ways that energy is moved 3) List 3 ways that energy is moved from place to place.from place to place.– Radiation, conduction, convectionRadiation, conduction, convection

RadiationRadiation

• 4) Earth’s surface 4) Earth’s surface becomes warmer becomes warmer when it is heated by when it is heated by radiationradiation from the from the sun.sun.

ConductionConduction

• 5) Explain why the bowl of the metal 5) Explain why the bowl of the metal spoon gets hot after resting in a mug spoon gets hot after resting in a mug of very hot cocoa.of very hot cocoa.– Energy is conducted from the hot liquid Energy is conducted from the hot liquid

to the bowl of the metal spoon.to the bowl of the metal spoon.

ConvectionConvection• 6) Complete the diagram to show 6) Complete the diagram to show

how convection works.how convection works.

Cool dense air sinks

Warm ground heats up air and air becomes less dense

Less dense, warm air rises

Ground

Radiation from Sun heats ground

Conduction occurs where air “touches” ground

Convection- the circulating motion of hot and cold.

Convection at workConvection at work

Hot material rises

Cold material sinks

The atmosphere has temperature The atmosphere has temperature layers.layers.

• Label the following 2 lowest layers of Label the following 2 lowest layers of the atmosphere.the atmosphere.

1) Stratosphere •Contains ozone•Temperature rises as move upward

2) Troposphere •Contains almost all H2O vapor in atmosphere•Contains most mass of atmosphere•Heated by ground, temperature falls as move upward

Layers of AtmosphereLayers of Atmosphere

Particles blocked by Particles blocked by atmosphereatmosphere

Atmosphere’s Temperature Atmosphere’s Temperature LayersLayers

• 8) Sometimes the tar of a newly 8) Sometimes the tar of a newly paved road gets sticky on a very hot paved road gets sticky on a very hot summer day. What causes this?summer day. What causes this?– Dark road absorbs solar radiation Dark road absorbs solar radiation

enough so it heats up and starts to melt enough so it heats up and starts to melt tar.tar.

15.3 Gases in the Atmosphere 15.3 Gases in the Atmosphere Absorb RadiationAbsorb Radiation• VocabularyVocabulary

– Ultraviolet radiationUltraviolet radiation– waves that have more energy – waves that have more energy than visible lightthan visible light

– Infrared radiationInfrared radiation– waves that have less energy than – waves that have less energy than visible lightvisible light

– Ozone– Ozone– a molecule containing three atoms of oxygena molecule containing three atoms of oxygen– Greenhouse effectGreenhouse effect– the process by which gases – the process by which gases

absorb and give off infrared radiation, which keeps absorb and give off infrared radiation, which keeps energy in Earth’s system for a whileenergy in Earth’s system for a while

– Greenhouse gasesGreenhouse gases– water vapor, carbon dioxide, – water vapor, carbon dioxide, methane, nitrous oxide, and other gases that absorb and methane, nitrous oxide, and other gases that absorb and give off infrared radiationgive off infrared radiation

• 1) What happens to solar radiation that 1) What happens to solar radiation that reaches Earth? reaches Earth? Some is reflected back into Some is reflected back into space while some is absorbed by Earth’s air, space while some is absorbed by Earth’s air, water, and land.water, and land.

Gases can absorb and give off Gases can absorb and give off radiationradiation

• 2) List four ways that gases in the 2) List four ways that gases in the atmosphere can affect radiation.atmosphere can affect radiation.– Absorb radiationAbsorb radiation– Reflect radiationReflect radiation– Let it pass through Let it pass through – Emit radiationEmit radiation

Gases Can Absorb and Give Off Gases Can Absorb and Give Off Radiation (continued)Radiation (continued)

• 3) Put descriptions of ultraviolet radiation and 3) Put descriptions of ultraviolet radiation and infrared radiation into the frame game infrared radiation into the frame game diagram.diagram.

• Ultraviolet radiationUltraviolet radiation– – like sound too high to like sound too high to hear, ozone absorbs it, shorter wavelength, has hear, ozone absorbs it, shorter wavelength, has more energy than visible lightmore energy than visible light

• Infrared radiation–Infrared radiation– like sound too low to like sound too low to hear, longer wavelength, has less energy than hear, longer wavelength, has less energy than visible light, greenhouse gases absorb and visible light, greenhouse gases absorb and reflect thisreflect this

Behavior of Ultra-Violet Behavior of Ultra-Violet RadiationRadiation

Behavior of Infrared Behavior of Infrared RadiationRadiation

The Ozone Layer Protects Life The Ozone Layer Protects Life from Harmful Radiationfrom Harmful Radiation

• Draw a picture to show the difference Draw a picture to show the difference between a molecule of oxygen gas between a molecule of oxygen gas and a molecule of ozone.and a molecule of ozone.

OO

2

3

Oxygen gas(breathable)

Ozone- reflects UV rays, but not breathable

Ozone LayerOzone Layer

• 5) List 3 ways that the ozone 5) List 3 ways that the ozone protects life on Earth.protects life on Earth.– Reduces sunburn and skin cancerReduces sunburn and skin cancer– Reduces damage to eyesightReduces damage to eyesight– Prevents crop damagePrevents crop damage

OzoneOzone

The Greenhouse Effect Keeps The Greenhouse Effect Keeps Earth WarmEarth Warm

• 6) Fill in the chart with facts about the 6) Fill in the chart with facts about the ozone layer and greenhouse effect.ozone layer and greenhouse effect.

LayerLayer Gas(es)Gas(es) Type of Type of radiation radiation absorbedabsorbed

Ozone Ozone layerlayer

stratospherestratosphere ozone (O3) ozone (O3) UltravioletUltraviolet

GreenhousGreenhouse effecte effect

TroposphereTroposphere Greenhouse Greenhouse gases (CO2 gases (CO2 and CO)and CO)

Infrared Infrared radiationradiation

Greenhouse EffectGreenhouse Effect

The Greenhouse Effect The Greenhouse Effect (continued)(continued)

• 7) What would happen on Earth if the 7) What would happen on Earth if the atmosphere didn’t have greenhouse atmosphere didn’t have greenhouse gases?gases?– Infrared radiation would bounce off Infrared radiation would bounce off

Earth’s surface into space leaving Earth’s surface into space leaving Earth’s average temperature at -18°C Earth’s average temperature at -18°C which is too cold for life dependant on which is too cold for life dependant on liquid water.liquid water.

15.4 Human Activities Affect 15.4 Human Activities Affect the Atmospherethe Atmosphere

• VocabularyVocabulary– Air pollutionAir pollution– harmful materials that are added to the – harmful materials that are added to the

airair– ParticulateParticulate– any tiny particle or droplet of harmful – any tiny particle or droplet of harmful

material that is mixed in with airmaterial that is mixed in with air– Fossil fuelFossil fuel– fuel formed from the remains of once-living – fuel formed from the remains of once-living

plants and animalsplants and animals– SmogSmog– a combination of fog and smoke, or ozone and – a combination of fog and smoke, or ozone and

other pollutants produced by sunlight and gasesother pollutants produced by sunlight and gases

• 1) What effect do greenhouse gases have on Earth?1) What effect do greenhouse gases have on Earth?– Greenhouse gases absorb and emit infrared radiation that Greenhouse gases absorb and emit infrared radiation that

heats Earth or keeps it warm.heats Earth or keeps it warm.

Human activity can cause Human activity can cause air pollutionair pollution

• 2) Suppose a factory in your town 2) Suppose a factory in your town released harmful substances into the released harmful substances into the air. Is the effect of this air pollution air. Is the effect of this air pollution limited to your town? Explain why or limited to your town? Explain why or why not…why not…– No! Air is fluid and will carry the No! Air is fluid and will carry the

pollution to other towns.pollution to other towns.

Types of PollutionTypes of Pollution

• Gas PollutantsGas Pollutants– COCO– MethaneMethane– Ozone Ozone – Sulfur oxideSulfur oxide

• Particle PollutantsParticle Pollutants– DustDust– DirtDirt– PollenPollen– SaltSalt

PollutantsPollutants

• 5) In cities, most air pollution comes 5) In cities, most air pollution comes from the burning of from the burning of fossil fuelsfossil fuels. . Smoke from this burning can Smoke from this burning can combine with water vapor in the air combine with water vapor in the air or fog to produce or fog to produce smogsmog..

Effects of PollutionEffects of Pollution

• 6) How does polluted air affect our 6) How does polluted air affect our health?health?– Examples: Irritates eyes, nose, throat Examples: Irritates eyes, nose, throat

and lungs. Causes allergies and and lungs. Causes allergies and breathing problems.breathing problems.

Controlling PollutionControlling Pollution

• 7) What are some things 7) What are some things governments do to control pollution governments do to control pollution and its effects?and its effects?– Smog and ozone laws to limit pollutants, Smog and ozone laws to limit pollutants,

laws to increase fuel efficiency.laws to increase fuel efficiency.

Human activities are Human activities are increasing greenhouse increasing greenhouse gases.gases.• 8) List three activities that can 8) List three activities that can

produce greenhouse gases.produce greenhouse gases.– CO2= burning of fossil fuels in cars, CO2= burning of fossil fuels in cars,

factories and power plantsfactories and power plants– Methane= cattle and livestock, landfills, Methane= cattle and livestock, landfills,

and bacteria in rice fieldsand bacteria in rice fields– NO2= fertilizers and chemical factoriesNO2= fertilizers and chemical factories

Global WarmingGlobal Warming

• 9) What do you expect to happen if 9) What do you expect to happen if greenhouse gases such as carbon greenhouse gases such as carbon dioxide keep increasing?dioxide keep increasing?– Global temperatures will continue to Global temperatures will continue to

rise. This can affect sources of food, rise. This can affect sources of food, water, and other resources available.water, and other resources available.

Reduction of Greenhouse Reduction of Greenhouse GasesGases

• 10) List three benefits of reducing 10) List three benefits of reducing the amount of energy needed to heat the amount of energy needed to heat buildings, transport people, and buildings, transport people, and make products.make products.– saves resourcessaves resources– Saves moneySaves money– Reduces greenhouse gases and other Reduces greenhouse gases and other

pollutantspollutants

Human activities produce Human activities produce chemicals that destroy the chemicals that destroy the ozone layerozone layer• 11) What happens when a chlorine 11) What happens when a chlorine

atom enters the stratosphere? Why atom enters the stratosphere? Why is this a bad thing?is this a bad thing?– It “steals” or takes an oxygen atom from It “steals” or takes an oxygen atom from

ozone molecules and thus depletes the ozone molecules and thus depletes the ozone layer. (With only 2 oxygen ozone layer. (With only 2 oxygen atoms, the molecule no longer protects atoms, the molecule no longer protects us from ultraviolet radiation.)us from ultraviolet radiation.)