Chapter 11, Section 1Chapter 11, Section 1The AtmosphereThe Atmosphere

1.1. Importance of the Importance of the atmosphereatmospherea.a. Def – thin layer of air that forms Def – thin layer of air that forms

protective covering around the planetprotective covering around the planetb.b. With no atmosphere, days would be With no atmosphere, days would be

extremely hot and nights would be coldextremely hot and nights would be coldc.c. Atmosphere protects life from Atmosphere protects life from

sunsun’’s harmful rayss harmful rays1.1. Harmful rays are called ultraviolet radiationHarmful rays are called ultraviolet radiation

What would Earth be like What would Earth be like without an atmosphere?without an atmosphere?

ExtremeTemps

Nosound

UV Radiation

2. Makeup of Atmosphere2. Makeup of Atmospherea.a. GasesGases

1.1. 78% of atmosphere is Nitrogen78% of atmosphere is Nitrogen2.2. 21% of atmosphere is Oxygen21% of atmosphere is Oxygen3.3. 1% is water vapor, carbon dioxide, trace 1% is water vapor, carbon dioxide, trace

gases like argongases like argonb.b. Solids & liquidsSolids & liquids

1.1. Solids include dust, salt, pollution, ash, pollenSolids include dust, salt, pollution, ash, pollen2.2. Liquids include water vaporLiquids include water vapor

a. a. TroposphereTroposphere1.1. Weather layerWeather layer2.2. We live in this layerWe live in this layer3.3. Water vapor & carbon dioxide are Water vapor & carbon dioxide are

important gases for weather conditionsimportant gases for weather conditions4.4. As altitude increases, air pressure As altitude increases, air pressure

decreases & temperature decreasesdecreases & temperature decreases1.1. Altitude sickness – humans feeling ill due to Altitude sickness – humans feeling ill due to

the effects of lowered air pressure at the effects of lowered air pressure at increased altitudesincreased altitudes

RollPresentation

Express

3. Layers of the Atmosphere3. Layers of the Atmosphere

TemperatureTemperature

Temperature Temperature

a. Troposphere (continued)a. Troposphere (continued)• Lowest layer of Lowest layer of

EarthEarth’’s s atmosphereatmosphere– Our weather layerOur weather layer– increase altitudeincrease altitude– Tropo= change in Tropo= change in

GreekGreek– Sphere = ballSphere = ball– Contains mass of Contains mass of

atmosphereatmosphere– Gets coolers as Gets coolers as

you increase you increase altitudealtitude

b.b. StratosphereStratosphere1.1. Strato = spreading out Strato = spreading out

(Gk)(Gk)2.2. Sphere = ball (Gk)Sphere = ball (Gk)3.3. 22ndnd layer from the layer from the

groundground4.4. Contains ozone (OContains ozone (O33) )

layerlayer5.5. Cold until you reach the Cold until you reach the

ozone layer at top of ozone layer at top of layer layer

6.6. Ozone layer is WARMOzone layer is WARM

c.c. MesosphereMesosphere1. 31. 3rdrd layer from the layer from the

groundground2. Meso = middle (Gk)2. Meso = middle (Gk)3. Sphere = ball (Gk)3. Sphere = ball (Gk)4. Coldest layer4. Coldest layer5. Most meteors burn 5. Most meteors burn

up in the up in the mesospheremesosphere

d. Thermosphered. Thermosphere

1. Hottest layer1. Hottest layer2. Thermo = Heat (Gk)2. Thermo = Heat (Gk)3. Sphere = ball (Gk)3. Sphere = ball (Gk)4. Satellites & shuttles 4. Satellites & shuttles

in orbitin orbit5. Air is extremely thin5. Air is extremely thin6. Ionosphere6. Ionosphere

-- layer of electrically -- layer of electrically charged particlescharged particles– AurorasAuroras

Amazing AurorasAmazing Auroras

d. Thermosphere d. Thermosphere (continued)(continued)

e. Exospheree. Exosphere1. Exo = outside (Gk)1. Exo = outside (Gk)2. Sphere = ball (Gk)2. Sphere = ball (Gk)3. Exits to deep space3. Exits to deep space4. Receives sun4. Receives sun’’s s

radiation firstradiation first

4. Atmospheric Pressure4. Atmospheric Pressure

Most Pressure

Least Pressure

Gravity pushing down

4. Atmospheric Pressure4. Atmospheric Pressurea.a. EarthEarth’’s gravity pulls air molecules s gravity pulls air molecules

toward Earthtoward Earth1.1. Molecules nearer EarthMolecules nearer Earth’’s surface are s surface are

closer together and therefore densercloser together and therefore denser2.2. This dense air exerts more force on an This dense air exerts more force on an

area. Force on an area is pressure.area. Force on an area is pressure.

5. Temperature in Atmospheric 5. Temperature in Atmospheric LayersLayersa.a. Sun is source of most of energy on Earth Sun is source of most of energy on Earth

& must pass through atmosphere to & must pass through atmosphere to reach the planetreach the planet

a.a. Troposphere is heated by sunlight passing Troposphere is heated by sunlight passing through and reflecting off Earththrough and reflecting off Earth’’s surfaces surface

b.b. Stratosphere is cold except at the top where Stratosphere is cold except at the top where ozone isozone is

c.c. Mesosphere is coldest layerMesosphere is coldest layerd.d. Thermosphere is hottest layerThermosphere is hottest layere.e. Thermosphere & exosphere receive sunThermosphere & exosphere receive sun’’s s

rays first but there are few molecules of airrays first but there are few molecules of air

6. Ozone Layer6. Ozone Layera.a. Located in stratosphereLocated in stratosphereb.b. Three bonded oxygen moleculesThree bonded oxygen moleculesc.c. Shields life on earth from harmful ultraviolet Shields life on earth from harmful ultraviolet

radiation radiation 1.1. UV is one of many types of energy that comes to Earth UV is one of many types of energy that comes to Earth

from sunfrom sun2.2. UV can cause sunburns and skin cancerUV can cause sunburns and skin cancer

d.d. Chlorofluorocarbons are chemical compounds Chlorofluorocarbons are chemical compounds that may destroy the ozone layerthat may destroy the ozone layer

1.1. Many countries have banned CFCMany countries have banned CFC’’s, which were found s, which were found in refrigerators, aerosol cans, and air conditionersin refrigerators, aerosol cans, and air conditioners

e.e. An ozone hole appears over Antarctica from An ozone hole appears over Antarctica from August -- OctoberAugust -- October