Atmosphere in MotionAtmosphere in MotionChapter 12Chapter 12

By Amy JohnsonBy Amy Johnson

AtmosphereAtmosphere

gases surrounding the Earthgases surrounding the Earth– necessary for supporting lifenecessary for supporting life– protects against harmful UV and X-ray protects against harmful UV and X-ray

radiationradiation– absorbs and distributes warmthabsorbs and distributes warmth

Galileo GalileiGalileo Galilei

proved air must have weight and contain proved air must have weight and contain mattermatter– Weighed flask, injected air, and reweighed to Weighed flask, injected air, and reweighed to

find flask with injected air weighed morefind flask with injected air weighed more Air stores and releases heat, holds moisture, Air stores and releases heat, holds moisture,

and can exert pressureand can exert pressure

Composition of AtmosphereComposition of Atmosphere

subject to the pull of gravitysubject to the pull of gravity– exerts pressure in all directions, therefore exerts pressure in all directions, therefore

cannot be feltcannot be felt– weight is equal to water over 10 m deepweight is equal to water over 10 m deep

mixture of gases, liquid water, and mixture of gases, liquid water, and microscopic particles of solids and other microscopic particles of solids and other liquidsliquids

Gases of the AtmosphereGases of the Atmosphere

Nitrogen – most abundant (78%)Nitrogen – most abundant (78%) Oxygen – necessary for human life (21%)Oxygen – necessary for human life (21%) Variety of other gases in trace amountsVariety of other gases in trace amounts

– water vapor is critical to weather (up to 4%)water vapor is critical to weather (up to 4%)» Responsible for clouds and precipitationResponsible for clouds and precipitation

– carbon dioxide allows plants to make food carbon dioxide allows plants to make food (.03%)(.03%)

» Absorbs heat and emits it back to warm EarthAbsorbs heat and emits it back to warm Earth

Aerosols in the AtmosphereAerosols in the Atmosphere

solids, such as dust, salt, and pollens and solids, such as dust, salt, and pollens and tiny droplets of acidtiny droplets of acid– dust comes from volcanoes and wind blowing dust comes from volcanoes and wind blowing

across the soilacross the soil– salt results from wind blowing over the oceansalt results from wind blowing over the ocean– pollen is released by plantspollen is released by plants– burning coal in power plants also creates burning coal in power plants also creates

aerosolsaerosols

Layers of the AtmosphereLayers of the Atmosphere

Lower LayersLower Layers– TroposphereTroposphere

– StratosphereStratosphere

Upper LayersUpper Layers– MesosphereMesosphere

» IonosphereIonosphere

– ThermosphereThermosphere

– ExosphereExosphere

based on temperature changes that occur with altitudebased on temperature changes that occur with altitude

TroposphereTroposphere

closest to the Earth (about 10 km)closest to the Earth (about 10 km) contains about ¾ of Earth’s entire contains about ¾ of Earth’s entire

atmosphere including clouds and weatheratmosphere including clouds and weather about 50% of Sun’s energy passes throughabout 50% of Sun’s energy passes through Earth’s surface heats by conductionEarth’s surface heats by conduction

– the farther from the surface you get, the cooler the farther from the surface you get, the cooler it becomesit becomes

StratosphereStratosphere

above troposphere (10 km – 50 km)above troposphere (10 km – 50 km) contains most of the ozonecontains most of the ozone

– Absorbs ultraviolet radiation to warm areaAbsorbs ultraviolet radiation to warm area» As you go up, you get warmerAs you go up, you get warmer

– without ozone, the UV radiation would reach without ozone, the UV radiation would reach Earth and cause health problemsEarth and cause health problems

MesosphereMesosphere

Extends 50km – 85km above surfaceExtends 50km – 85km above surface Contains very little ozone so temperature Contains very little ozone so temperature

drops to the lowest in atmospheredrops to the lowest in atmosphere

IonosphereIonosphere

part of mesosphere and thermospherepart of mesosphere and thermosphere due to intense interaction with the sun’s due to intense interaction with the sun’s

radiationradiation reflects AM radio waves allowing long-reflects AM radio waves allowing long-

distance communications possibledistance communications possible– static results when interaction between this static results when interaction between this

layer and radiation is too activelayer and radiation is too active

ThermosphereThermosphere

reaches 85km – 500kmreaches 85km – 500km temperatures increase rapidlytemperatures increase rapidly filters out harmful X-rays and gamma rays filters out harmful X-rays and gamma rays

from the Sunfrom the Sun

ExosphereExosphere

outermost layeroutermost layer extends outward to where space beginsextends outward to where space begins

– no clear boundary to spaceno clear boundary to space

GREENHOUSE EFFECT

Earth’s WaterEarth’s Water

70% of Earth’s surface is water70% of Earth’s surface is water Stored throughout the land-ocean-Stored throughout the land-ocean-

atmosphere system in three different statesatmosphere system in three different states– Solid – snow, ice, glaciersSolid – snow, ice, glaciers– Liquid – oceans, lakes, riversLiquid – oceans, lakes, rivers– Gas – water vaporGas – water vapor

Water CycleWater Cycle