Earths AtmosphereEarths Atmosphere

Chapter 1:Chapter 1:Earth’s Changing Earth’s Changing

AtmosphereAtmosphere1.1 Earth’s Atmosphere Supports Life1.1 Earth’s Atmosphere Supports Life

AirAir – mixture of gases – mixture of gases

Atmosphere Atmosphere – layer of air that surrounds – layer of air that surrounds the the Earth Earth

1. Supports life and protects it1. Supports life and protects it

2. Keeps Earth warm2. Keeps Earth warm

3. Transports energy3. Transports energy

Characteristics of the Characteristics of the AtmosphereAtmosphere

AltitudeAltitude – distance above sea level – distance above sea level

The thickness or thinness of air is The thickness or thinness of air is measured by its measured by its densitydensity..

DensityDensity – the amount of mass in a – the amount of mass in a given volume of a substancegiven volume of a substance

*Atmosphere’s density *Atmosphere’s density decreasesdecreases as as you travel upward.you travel upward.

Gases in the atmosphereGases in the atmosphere::

Nitrogen (NNitrogen (N22) – 78%) – 78%Oxygen (OOxygen (O22) – 21%) – 21%

Carbon Dioxide (COCarbon Dioxide (CO22), argon, other gases – 1%), argon, other gases – 1%

Nitrogen – promotes plant growthNitrogen – promotes plant growth Oxygen – animals and plants perform life Oxygen – animals and plants perform life

processesprocesses Carbon dioxide – plants use to make foodCarbon dioxide – plants use to make food

Cycles – processes that are repeated Cycles – processes that are repeated over and over againover and over again

11. . Carbon CycleCarbon Cycle : : a. Oxygen inhaled by animals, exhales a. Oxygen inhaled by animals, exhales

Carbon Dioxide (CO2)Carbon Dioxide (CO2)

b. CO2 taken in by plants, releases b. CO2 taken in by plants, releases Oxygen (O2)Oxygen (O2)

2. 2. Nitrogen CycleNitrogen Cycle : : a. tiny organisms (living things) remove N2 from a. tiny organisms (living things) remove N2 from

air, changes it into other chemicals and air, changes it into other chemicals and returns it to the soil. returns it to the soil.

b. plants/animals use solids/liquids that contain b. plants/animals use solids/liquids that contain N2, then return to soil when they die & N2, then return to soil when they die &

decay.decay. c. soil slowly releases N2 back in the airc. soil slowly releases N2 back in the air

3. 3. Water Cycle:Water Cycle: a. Liquid water from oceans & lakes changes intoa. Liquid water from oceans & lakes changes into gas (evaporates) and enters atmospheregas (evaporates) and enters atmosphere b. Plants release water vapor from leavesb. Plants release water vapor from leaves c. Liquid water falls back to atmosphere asc. Liquid water falls back to atmosphere as precipitation – rain, snow, sleet, or hail.precipitation – rain, snow, sleet, or hail.

Sudden Changes:Sudden Changes:

****Volcanic eruptions, forest Volcanic eruptions, forest fires, dust stormsfires, dust storms can cause can cause changes in the atmospherechanges in the atmosphere

Volcanic EruptionsVolcanic Eruptions – shoots gases and ash into – shoots gases and ash into the atmosphere.the atmosphere.

Forest FiresForest Fires – when forests burn, carbon that – when forests burn, carbon that makes up the trees enters the atmosphere as makes up the trees enters the atmosphere as carbon dioxide.carbon dioxide.

Dust StormsDust Storms – Adds huge amounts of particles to – Adds huge amounts of particles to the air.the air.

Section 1.2: The Sun Supplies Section 1.2: The Sun Supplies the Atmosphere’s Energythe Atmosphere’s Energy

Two main things happen to Two main things happen to sunlight when it hits the Earth:sunlight when it hits the Earth:

1. 1. Sunlight is reflected Sunlight is reflected – you see – you see most objects by reflected sunlightmost objects by reflected sunlight

2. 2. Sunlight is absorbed Sunlight is absorbed – sand – sand absorbs sunlight & becomes absorbs sunlight & becomes warmwarm

The Atmosphere Moves EnergyThe Atmosphere Moves Energy

Processes that move Processes that move EnergyEnergy from place to from place to place:place:

Radiation Radiation - Energy that travels distances in waves, can - Energy that travels distances in waves, can be absorbed or reflected.be absorbed or reflected.

ConductionConduction – Transfer of heat energy from one substance – Transfer of heat energy from one substance to another by direct contact.to another by direct contact.

ConvectionConvection – Transfer of energy by the motion of gas or – Transfer of energy by the motion of gas or liquid. Movement of gases up and down. Warm air rises, liquid. Movement of gases up and down. Warm air rises, cool air sinks.cool air sinks.

Example:Example:1. 1. RadiationRadiation from sun warms the sand from sun warms the sand2. Hot sand 2. Hot sand conductsconducts energy to feet, energy to feet,

air –or air –or anything that touches the sandanything that touches the sand

3. Warm air carries energy upward by 3. Warm air carries energy upward by convectionconvection

1.3 - Gases in the Atmosphere 1.3 - Gases in the Atmosphere pgs. 22-25pgs. 22-25

Atmosphere effects light in 4 ways:Atmosphere effects light in 4 ways: Absorb lightAbsorb light Reflect lightReflect light Let it pass throughLet it pass through Give off light – emit lightGive off light – emit light

1.3 - Two types of radiation 1.3 - Two types of radiation (energy):(energy):

1. Ultraviolet radiation – waves of 1. Ultraviolet radiation – waves of energy you can’t see, causes energy you can’t see, causes sunburn.sunburn.

2. infrared radiation – warms the 2. infrared radiation – warms the materials that absorb it.materials that absorb it.

1.3 - Earth’s Protection:1.3 - Earth’s Protection:

Ozone layer – ozone gases in the stratosphere, Ozone layer – ozone gases in the stratosphere, protects life on earth by absorbing harmful protects life on earth by absorbing harmful ultraviolet rays from sun.ultraviolet rays from sun.

Greenhouse effect – traps heat – absorbs Greenhouse effect – traps heat – absorbs gases (carbon dioxide, methane, etc.) and gases (carbon dioxide, methane, etc.) and keeps earth warm – allows heat to go back into keeps earth warm – allows heat to go back into space.space.

Keeps Earth’s average surface temp. around Keeps Earth’s average surface temp. around 59 degrees.59 degrees.

Air Masses 3.1 – pgs. 79-82Air Masses 3.1 – pgs. 79-82

Air MassAir Mass – large body of air. covers – large body of air. covers thousands of miles.thousands of miles.

Characteristics of Air Mass:Characteristics of Air Mass: depends on depends on where it forms and the temperature where it forms and the temperature

1st word tells where it forms (land or 1st word tells where it forms (land or water)water)

2nd word tells temp. (near or far from 2nd word tells temp. (near or far from equator) equator)

Four Types:Four Types: Continental Tropical – dry and warmContinental Tropical – dry and warm Continental Polar – dry and coolContinental Polar – dry and cool Maritime Tropical – moist and warmMaritime Tropical – moist and warm Maritime Polar – moist and coolMaritime Polar – moist and cool

Air Masses move from West to East Air Masses move from West to East – away – away from where they start.from where they start.

Takes on characteristics of earth’s surface Takes on characteristics of earth’s surface as it moves.as it moves.

FrontFront – boundary between air masses. – boundary between air masses.fronts are often cloudy or stormyfronts are often cloudy or stormy

3 types3 types:: Cold FrontCold Front – cold air mass pushes a warm air mass. – cold air mass pushes a warm air mass.

Produces cumulonimbus clouds. Brief heavy Produces cumulonimbus clouds. Brief heavy storms. storms. Cool weatherCool weather

Warm FrontWarm Front – warm air mass pushes cold air mass. – warm air mass pushes cold air mass.Hours of rain or snow – warm airHours of rain or snow – warm air

Stationary FrontStationary Front – Two air masses push against each – Two air masses push against each other and stop moving. other and stop moving. Becomes warm or cold when one air mass Becomes warm or cold when one air mass advances.advances.

Storms: 3.2 – 3.3 pgs. 87 – Storms: 3.2 – 3.3 pgs. 87 – 9797

Storms – 3.2Storms – 3.2 High pressure systemHigh pressure system – can bring clear – can bring clear

skies, calm air, gentle breezesskies, calm air, gentle breezes

Low Pressure systemLow Pressure system – brings stormy – brings stormy weatherweather

Tropical StormTropical Storm – low pressure system – low pressure system that starts at the equator – winds 40 mph that starts at the equator – winds 40 mph (65k)(65k)

HurricaneHurricaness HurricaneHurricane – low pressure system – winds – low pressure system – winds

74 mph (120k)74 mph (120k)

Hurricane strike between Aug. thru Oct. – Hurricane strike between Aug. thru Oct. – when water gets warm enough – loses when water gets warm enough – loses strength when reaches landstrength when reaches land

Eye of HurricaneEye of Hurricane – center of storm, calm – center of storm, calm windswinds

Storm SurgeStorm Surge – pushes huge mass of – pushes huge mass of ocean water onto coastal area.ocean water onto coastal area.

Winter storms result of two air masses Winter storms result of two air masses colliding.colliding.

NWS – National Weather Service – alerts NWS – National Weather Service – alerts people to dangerous weather.people to dangerous weather.

BlizzardsBlizzards – Blinding snowstorms, winds – Blinding snowstorms, winds 35mph, occur in northern and central 35mph, occur in northern and central U.S.U.S.

Ice stormsIce storms – rain falls onto freezing cold – rain falls onto freezing cold ground.ground.

covers everythincovers everything with iceg with ice

Severe Storms – 3.3Severe Storms – 3.3

LightningLightning – spark of electricity – spark of electricity

Air around lightning is heated briefly to Air around lightning is heated briefly to temp. hotter than the temp. hotter than the surface of sunsurface of sun

ThunderThunder – sharp wave of heated air that – sharp wave of heated air that travels away from lightningtravels away from lightning

ThunderstormThunderstorm – storm with lightning and – storm with lightning and thunder – get energy from humid air.thunder – get energy from humid air.

Effects of Thunderstorms: Effects of Thunderstorms: Flash floods, winds, hail, lightningFlash floods, winds, hail, lightning

Tornado – violently rotating column of air Tornado – violently rotating column of air – occurs mostly in spring - unpredictable– occurs mostly in spring - unpredictable