Characteristics of the Characteristics of the AtmosphereAtmosphere

Chapter 1 Chapter 1

77thth Grade Science Grade Science

AtmosphereAtmosphere

1. 1. AtmosphereAtmosphere- mixture of gases that - mixture of gases that surrounds the earthsurrounds the earth

– A. Contains the A. Contains the oxygenoxygen we need we need– B. Protects us from B. Protects us from the sun’s uv raysthe sun’s uv rays– C. C. Is always changingIs always changing– D. Held around the D. Held around the earthearth by gravity by gravity

What is in the atmosphere?What is in the atmosphere?

The Composition of the atmosphereThe Composition of the atmosphere

Atmosphere

78% Nitrogen 21% OxygenDust, dirt, smoke, sea

salt, volcanic ash

What is in the atmosphere?What is in the atmosphere?

1. Water1. Water– A. A. Liquid waterLiquid water (droplets) (droplets)– B. Solid water (snow and ice)B. Solid water (snow and ice)– C. C. Water vaporWater vapor

2. When conditions of the atmosphere change2. When conditions of the atmosphere change– A. Water vapor can change into A. Water vapor can change into snowsnow or or liquid waterliquid water

and…..and…..– B. Rain or snow might B. Rain or snow might fall from the skyfall from the sky

Atmospheric Pressure and Atmospheric Pressure and TemperatureTemperature

1. Gravity pulls 1. Gravity pulls gas moleculesgas molecules towards the towards the Earth’s surface causing Earth’s surface causing air pressureair pressure

2. 2. Air pressure-Air pressure- the measure of force with the measure of force with which air molecules push on a surfacewhich air molecules push on a surface

3. Think of air pressure as a 3. Think of air pressure as a human human pyramid-pyramid-

the people at the bottom can feel the weight the people at the bottom can feel the weight and pressure of the people on topand pressure of the people on top

Human PyramidHuman Pyramid

Atmospheric Composition (Make up) Atmospheric Composition (Make up) Affects Air TemperatureAffects Air Temperature

1. Air temperature changes as 1. Air temperature changes as altitudealtitude (height) (height) increasesincreases

2. Temperatures changes as different gases 2. Temperatures changes as different gases absorb absorb solar energysolar energy more than others more than others

Bell WorkBell Work

1.1. What is the composition of the What is the composition of the atmosphere?atmosphere?

True or FalseTrue or False

2.______ Air pressure increases closer to the 2.______ Air pressure increases closer to the Earth’s surface.Earth’s surface.

3.______ Atmosphere is a mixture of gases 3.______ Atmosphere is a mixture of gases that surrounds a planet or moon.that surrounds a planet or moon.

Layers of the AtmosphereLayers of the Atmosphere

Troposphere, Stratosphere, Mesosphere, Troposphere, Stratosphere, Mesosphere, Thermosphere, Ionosphere, ExosphereThermosphere, Ionosphere, Exosphere

Vocabulary (Make index cards)Vocabulary (Make index cards)– Sphere = ballSphere = ball– Tropo = turning or changeTropo = turning or change– Strato = layerStrato = layer– Meso = middleMeso = middle– Thermo = heatThermo = heat– Exo = outside or exitExo = outside or exit

Layers of the AtmosphereLayers of the Atmosphere

ExosphereExosphere

ThermosphereThermosphere

MesosphereMesosphere

StratosphereStratosphere

TroposphereTroposphere

TroposphereTroposphere

1. 1. Lowest layerLowest layer of the atmosphere, closest of the atmosphere, closest to Earthto Earth

2. More 2. More densedense 3. Contains almost all of the 3. Contains almost all of the COCO22, water , water

vapor, vapor, cloudsclouds, air pollution, , air pollution, weatherweather and life and life formsforms

4. Different 4. Different airair temperatures and temperatures and densitydensity causes gases to mix continuouslycauses gases to mix continuously

StratosphereStratosphere

1. Layer above the troposphere1. Layer above the troposphere 2. Gases are 2. Gases are layeredlayered and do not mix very and do not mix very

muchmuch 3. Air is very 3. Air is very thinthin and contains and contains little little moisturemoisture 4. 4. Cold Cold temperatures in the lower temperatures in the lower

stratospherestratosphere 5. Temperatures rise as the altitude 5. Temperatures rise as the altitude

increasesincreases because the because the ozoneozone absorbs uv absorbs uv radiation from the sunradiation from the sun

MesosphereMesosphere

1. 1. MiddleMiddle Layer Layer 2. 2. ColdestColdest Layer Layer 3. Temperatures 3. Temperatures decreasedecrease as altitude as altitude

increasesincreases

ThermosphereThermosphere

1. 1. UpperUpper layer layer 2. Temperatures 2. Temperatures increaseincrease as altitude as altitude

increasesincreases 3. 3. LessLess dense dense 4. Particles do not often 4. Particles do not often collidecollide and do not and do not

transfertransfer much energy much energy 5. Includes the 5. Includes the IonosphereIonosphere

IonosphereIonosphere

1. Part of the Thermosphere1. Part of the Thermosphere 2. Contains electrically charged 2. Contains electrically charged ionsions 3. In 3. In polarpolar regions, these ions radiate regions, these ions radiate

energy as energy as shimmering lightsshimmering lights called, auroras called, auroras (known as northern or southern lights)(known as northern or southern lights)

ExosphereExosphere

1. Very 1. Very thinthin layer layer 2. Layer where atoms and molecules 2. Layer where atoms and molecules

““escape or exitescape or exit” into space” into space

Bell WorkBell Work

Write the meaning of each wordWrite the meaning of each word– Sphere = Sphere = – Tropo = Tropo = – Strato = Strato = – Meso = Meso = – Thermo = Thermo = – Exo = Exo =

ProjectProject

1.Draw a model of the layers of the atmosphere. 1.Draw a model of the layers of the atmosphere.

2. Include the 5 layers. 2. Include the 5 layers. LabelLabel them: Troposphere, them: Troposphere, Stratosphere, Mesosphere, Thermosphere Stratosphere, Mesosphere, Thermosphere (Ionosphere), and Exosphere. (Ionosphere), and Exosphere. LabelLabel the altitude. the altitude. Shown on page 6 in your book)Shown on page 6 in your book)

3. Include what each layer contains and the 3. Include what each layer contains and the characteristics of each layer. Use your characteristics of each layer. Use your booksbooks and and notesnotes, include such things as ozone layer, space , include such things as ozone layer, space ships, air planes, satellites, northern lightsships, air planes, satellites, northern lights

Bell WorkBell Work

1.1. Which layer of the atmosphere is the Which layer of the atmosphere is the coldest?coldest?

2.2. Where is there more air pressure? On top Where is there more air pressure? On top of the building or in the basement.of the building or in the basement.

3.3. Which layer of the atmosphere is the most Which layer of the atmosphere is the most dense?dense?

4.4. Which layer of the atmosphere contains Which layer of the atmosphere contains the northern lights?the northern lights?

Bell workBell work

1. What are the two main gases in Earth’s 1. What are the two main gases in Earth’s atmosphere?atmosphere?

2. What is atmospheric pressure?2. What is atmospheric pressure? 3. Name the layers of the atmosphere, 3. Name the layers of the atmosphere,

starting with the one closest to Earthstarting with the one closest to Earth 4. What is the ozone layer, and why is it 4. What is the ozone layer, and why is it

important to Earth?important to Earth? 5. Explain how density affects energy 5. Explain how density affects energy

transfer in the air.transfer in the air.

ConductionConductionEnergy Transfer by ContactEnergy Transfer by Contact

1. 1. Thermal ConductionThermal Conduction- transfer of energy - transfer of energy through a materialthrough a material

2. Thermal energy is always transferred 2. Thermal energy is always transferred from a from a warmwarm to a to a coldcold area area

3. Making popcorn the “3. Making popcorn the “old-fashionold-fashion” way in a ” way in a pan on the stovepan on the stove– Heat is Heat is transferredtransferred from the pan to the from the pan to the oiloil, to the , to the

popcorn kernelspopcorn kernels– Just like the Just like the airair by the Earth’s surface is by the Earth’s surface is heatedheated

ConvectionConvectionEnergy Transfer by CirculationEnergy Transfer by Circulation

1. 1. ConvectionConvection- transfer of thermal energy by the circulation - transfer of thermal energy by the circulation or movement of a liquid or a gasor movement of a liquid or a gas– Cool airCool air is more is more densedense and it and it sinkssinks– Warm airWarm air is less is less densedense and it and it risesrises

2. The 2. The rising rising and and fallingfalling of air causes a of air causes a circularcircular movement movement and is called a and is called a convectionconvection current current

3. Making popcorn in a popcorn popper3. Making popcorn in a popcorn popper– the warm air makes the kernels expand and popthe warm air makes the kernels expand and pop– Just like radiation from the sun Just like radiation from the sun heatsheats the air in the atmosphere the air in the atmosphere

The warm air The warm air risesrises, allowing cool air to move , allowing cool air to move underneathunderneath it it

RadiationRadiationEnergy Transfer by WavesEnergy Transfer by Waves

1. Earth receives energy from the 1. Earth receives energy from the sunsun by radiation by radiation 2. 2. RadiationRadiation-transfer of energy as -transfer of energy as electromagnetic electromagnetic

waveswaves– Earth receives about Earth receives about two-billionthstwo-billionths of the sun’s energy of the sun’s energy– This is enough to drive the This is enough to drive the weatherweather cycle and make the cycle and make the

Earth Earth habitablehabitable

3. Making popcorn in the 3. Making popcorn in the microwavemicrowave– The kernels are heated by The kernels are heated by radiationradiation from the microwave from the microwave– Causing them to Causing them to poppop and give off heat and give off heat

Bell WorkBell Work

1. What layer of the atmosphere is the most 1. What layer of the atmosphere is the most dense?dense?

2. In what layer of the atmosphere would you 2. In what layer of the atmosphere would you find the ozone layer?find the ozone layer?

3.What is the definition of thermal conduction?3.What is the definition of thermal conduction?

4. What is the definition of convection?4. What is the definition of convection?

5. How does Earth receive energy from the 5. How does Earth receive energy from the sun?sun?

Greenhouse EffectGreenhouse Effect

1. 1. Greenhouse effect-Greenhouse effect- when gases (CO when gases (CO22 and H and H22O O vapor )in the atmosphere vapor )in the atmosphere absorbabsorb thermal energy thermal energy and and radiateradiate it back to Earth it back to Earth

2. These gases function like 2. These gases function like glass wallsglass walls on top of on top of a a greenhousegreenhouse– A. They allow solar energy to A. They allow solar energy to enterenter Earth’s atmosphere Earth’s atmosphere– B. But they B. But they preventprevent thermal energy from thermal energy from escapingescaping

Radiation Balance-Radiation Balance-balance between the incoming balance between the incoming energy from the sun and the energy that is allowed energy from the sun and the energy that is allowed to leave Earth’s atmosphereto leave Earth’s atmosphere

What happens when there is not What happens when there is not radiation balance?radiation balance?

1. Global warming-1. Global warming-increaseincrease in global in global temperaturestemperatures

2. Scientists believe2. Scientists believe– A. An increase in greenhouse gases in the A. An increase in greenhouse gases in the

atmosphereatmosphere AbsorbAbsorb more thermal energy, causing temperatures more thermal energy, causing temperatures

to riseto rise

– B. Human activity like burning B. Human activity like burning fossil fuelsfossil fuels and and deforestationdeforestation Have Have increasedincreased levels of these greenhouse gases levels of these greenhouse gases

Bell WorkBell Work

1.1. Which layer of the atmosphere is the Which layer of the atmosphere is the coldest?coldest?

2.2. What is the transfer of energy from What is the transfer of energy from electromagnetic waves?electromagnetic waves?

3.3. What happens when gases (COWhat happens when gases (CO22 and H and H22O O

vapor )in the atmosphere absorb thermal vapor )in the atmosphere absorb thermal energy and radiate it back to Earth?energy and radiate it back to Earth?

Bell WorkBell Work

1.1. Why do they call the warming of global Why do they call the warming of global temperatures the greenhouse effect?temperatures the greenhouse effect?

Answer: The earth’s temperatures are Answer: The earth’s temperatures are warming because the atmosphere is acting warming because the atmosphere is acting like a greenhouse. The sun’s energy is like a greenhouse. The sun’s energy is being let in and not being allowed to being let in and not being allowed to escape. This is causing temperatures to escape. This is causing temperatures to rise. rise.

2.What is the definition of air pollution?2.What is the definition of air pollution?

Bell WorkBell Work

1. Define radiation balance.1. Define radiation balance.

2. Name the layers of the atmosphere in 2. Name the layers of the atmosphere in order.order.

3. Define and give an example of 3. Define and give an example of convection.convection.

Air PollutionAir Pollution

London, December 1952London, December 1952 ““pea soup” fog that contain pea soup” fog that contain

coal smoke and air coal smoke and air pollutionpollution

People could not see their People could not see their hands in front of their hands in front of their facesfaces

Burned people’s lungsBurned people’s lungs Killed thousands of people Killed thousands of people

Air PollutionAir Pollution

1. 1. Air pollution-Air pollution- contamination of the contamination of the environment from pollutants caused by environment from pollutants caused by humans and natural sourceshumans and natural sources

Primary PollutantsPrimary Pollutants 1. 1. Primary pollutants-Primary pollutants-pollutants put directly into the pollutants put directly into the

air by air by humanshumans or or natural sourcesnatural sources– Examples: Examples: dustdust, sea salt, , sea salt, volcanic gasesvolcanic gases, ash, smoke from , ash, smoke from

forest fires, and forest fires, and pollenpollen

Secondary PollutantsSecondary Pollutants

1.1. Secondary Pollutants- Secondary Pollutants-happens when primary happens when primary pollutants react with pollutants react with other primary pollutants other primary pollutants or other naturally or other naturally occurring substances occurring substances (water vapor)(water vapor)

ExamplesExamples-ozone and -ozone and smogsmog

OzoneOzone

1. In the stratosphere –ozone protects Earth 1. In the stratosphere –ozone protects Earth from harmful uv raysfrom harmful uv rays– This ozone is This ozone is goodgood

2. Near the Earth’s surface- ozone is formed 2. Near the Earth’s surface- ozone is formed when sunlight reacts with vehicle exhaustwhen sunlight reacts with vehicle exhaust– This ozone is This ozone is dangerousdangerous

SmogSmog

1. Smog1. Smog– Forms when Forms when ozoneozone and and vehicle exhaustvehicle exhaust react react

with sunlightwith sunlight– Problem for Los Angelos and other big citiesProblem for Los Angelos and other big cities

Classifying PollutantsClassifying Pollutants

smog, house dust, acid rain, pollen, soot, smog, house dust, acid rain, pollen, soot, ground-level ozone, volcanic ashground-level ozone, volcanic ash

Primary PollutantPrimary Pollutant Secondary Secondary PollutantPollutant

Sources of Human-Caused Air Sources of Human-Caused Air PollutionPollution

1. 1. Car exhaustCar exhaust 2. Industries2. Industries

– Dry cleaningDry cleaning– Furniture refinishersFurniture refinishers– Auto body shopsAuto body shops

3. Cleaning supplies3. Cleaning supplies

Cleaning Up Air PollutionCleaning Up Air Pollution

1. The Clean Air Act1. The Clean Air Act– A. Allows the Environmental Protection Agency A. Allows the Environmental Protection Agency

((EPAEPA) to control the amount of air pollution that ) to control the amount of air pollution that can be released from any source, such as cars can be released from any source, such as cars and factoriesand factories

– B. EPA also checks B. EPA also checks air qualityair quality– C. Requires many industries to use C. Requires many industries to use scrubbersscrubbers

Scrubbers are in Scrubbers are in smokestacks smokestacks and remove particles and remove particles such as ash from smokesuch as ash from smoke

Review of Radiation, Conduction, Review of Radiation, Conduction, and Convection Energy Transferand Convection Energy Transfer

Radiation-transfer of energy as Radiation-transfer of energy as electromagnetic waves electromagnetic waves

Convection- transfer of thermal energy by Convection- transfer of thermal energy by the circulation or movement of a liquid or a the circulation or movement of a liquid or a gasgas

Thermal Conduction- transfer of energy Thermal Conduction- transfer of energy through a materialthrough a material

ReviewReview Classify the following examples Classify the following examples

ConductionConduction

RadiationRadiation

Convection Convection

campfire ,a candle, an campfire ,a candle, an egg frying on a hot egg frying on a hot sidewalk, the sun, hot sidewalk, the sun, hot air rising, cooling and air rising, cooling and falling, a toaster, ice falling, a toaster, ice melting in your hand, melting in your hand, microwave, a light microwave, a light bulb, making grilled bulb, making grilled cheese, air popcorn cheese, air popcorn popperpopper

ReviewReview Classify the following examples Classify the following examples

ConductionConduction Radiation Radiation Convection Convection

Chapter Review pages 30-31Chapter Review pages 30-31

# 1,2,3,4,6# 1,2,3,4,6 #7-13, 15,16#7-13, 15,16 # 18# 18 # 20# 20 #22#22 #26,27#26,27