The The AtmosphereAtmosphere

The Air Around YouThe Air Around You Earth's Earth's atmosphereatmosphere is the envelope of gases that surrounds is the envelope of gases that surrounds

the planet.the planet. made up of nitrogen, oxygen, carbon dioxide, made up of nitrogen, oxygen, carbon dioxide,

water vapor, and many other gases, as well as water vapor, and many other gases, as well as particles of liquids and solidsparticles of liquids and solids

WeatherWeather is the condition of Earth's atmosphere is the condition of Earth's atmosphere

Air PressureAir Pressure Air pressure Air pressure is the result of is the result of

the the weight of a column of air weight of a column of air pushing down on an area.pushing down on an area.

• 14.7 lbs/inch14.7 lbs/inch22 • 1013.25 millibars1013.25 millibars• 1013.25 hPa (hecto Pascals)1013.25 hPa (hecto Pascals)• 29.92 inches of Hg29.92 inches of Hg

1 in x 1 in square column of air weighs 14.7 lbs at sea level

Measuring Measuring Air PressureAir Pressure barometerbarometer is an instrument that is used to measure air

pressure. mercury barometer consists of a glass tube open at the

bottom end and partially filled with mercury aneroid barometer has an airtight metal chamber

Air Pressure & Air Pressure & AltitudeAltitude Elevation – the distance above sea level. As altitude increases Air pressure decreases As air pressure decreases, so does density.

Layers of the Layers of the AtmosphereAtmosphere Scientists divide Earth's Scientists divide Earth's

atmosphere into four main layers atmosphere into four main layers classified according to changes in classified according to changes in temperaturetemperature.. TroposphereTroposphere – sea level to 12 – sea level to 12

km km All weather occurs hereAll weather occurs here

StratosphereStratosphere – from 12 to 50 km – from 12 to 50 km Ozone layer, protects from UV, sets Ozone layer, protects from UV, sets

fly herefly here

MesosphereMesosphere – from 50 to 80 km – from 50 to 80 km Dense enough to burn meteoroidsDense enough to burn meteoroids

ThermosphereThermosphere – above 80 km, – above 80 km, made up of 2 layersmade up of 2 layers

IonosphereIonosphere – 80 km to 400 km – 80 km to 400 km Gas particles electrically chargedGas particles electrically charged Radio waves reflect back to Earth from hereRadio waves reflect back to Earth from here Aurora borealis occur hereAurora borealis occur here

ExosphereExosphere – above 400 km – above 400 km Satellites orbit here Satellites orbit here

Layers of the Layers of the AtmosphereAtmosphere

The term “pause” refers to “between” layers.

Layers of the Layers of the AtmosphereAtmosphere

Energy in Earth's Energy in Earth's AtmosphereAtmosphere Energy travels to Earth as electromagnetic radiation from the SunEnergy travels to Earth as electromagnetic radiation from the Sun

EMR travels through the atmosphere & heats the surface of the EarthEMR travels through the atmosphere & heats the surface of the Earth When Earth's surface is heated, it radiates most of the energy back into the atmosphere as infrared When Earth's surface is heated, it radiates most of the energy back into the atmosphere as infrared

radiation.radiation.

Heat Transfer in the Heat Transfer in the AtmosphereAtmosphere

Thermal energy Thermal energy - - total energy of motion in the particles of total energy of motion in the particles of a substancea substance

TemperatureTemperature – the average thermal energy of the – the average thermal energy of the substance particlessubstance particles

HeaHeat - t - transfer of thermal energy from a hotter object to a transfer of thermal energy from a hotter object to a cooler onecooler one Transferred in 1 of 3 ways:Transferred in 1 of 3 ways:

RadiationRadiation ConductionConduction Convection Convection

WindsWinds WindWind is the movement of air from is the movement of air from

an area of high pressure to an an area of high pressure to an area of lower pressure.area of lower pressure.

Winds are caused by Winds are caused by differences in air pressuredifferences in air pressure caused by unequal heating of the caused by unequal heating of the atmosphereatmosphere

Wind Direction / Wind Wind Direction / Wind SpeedSpeed Wind speed is measured with an Wind speed is measured with an anemometeranemometer..

The name of a wind tellsThe name of a wind tells

you the direction the you the direction the

wind is coming from.wind is coming from.

Sea breezes & Land breezes are Sea breezes & Land breezes are Local Winds Local Winds caused by the unequal heating of Earth's surfacecaused by the unequal heating of Earth's surface

Coriolis EffectCoriolis Effect Because Earth is rotating, global winds do not follow a straight path. Because Earth is rotating, global winds do not follow a straight path.

The way Earth's rotation makes winds curve is called the The way Earth's rotation makes winds curve is called the Coriolis Coriolis effect. effect. In the Northern Hemisphere, global winds curve to the right. In the Northern Hemisphere, global winds curve to the right. In the Southern Hemisphere, global winds curve to the left.In the Southern Hemisphere, global winds curve to the left.

Global Winds occur over a large area & Global Winds occur over a large area & are affected by the are affected by the Coriolis Effect Coriolis Effect

(caused by the rotation of the Earth)(caused by the rotation of the Earth) The WindsThe Winds

Trade winds Trade winds blow from blow from the NE between Equator the NE between Equator & 30N& 30N

Prevailing Westerlies Prevailing Westerlies blow from the SW blow from the SW between 30N & 60 Nbetween 30N & 60 N

Polar Easterlies Polar Easterlies 60 N to 60 N to 90 90

Calm areas:Calm areas: DoldrumsDoldrums along the along the

equatorequator The The Horse Latitudes Horse Latitudes

around 30 N & S around 30 N & S

Jet Stream Jet Stream High speed wind High speed wind

currents about 150 currents about 150 mph that are 10-15 mph that are 10-15 km above the surfacekm above the surface

The Water CycleThe Water Cycle

Evaporation CondensationPrecipitationRunoff