Our AtmosphereOur Atmosphere

CompositionComposition

78% 78% NitrogenNitrogen remain remain

21% 21% OxygenOxygen constant constant

1% 1% Trace gases, Carbon Dioxide, Water Trace gases, Carbon Dioxide, Water Vapor, dustVapor, dust

**concentration water vapor in the **concentration water vapor in the atmosphere atmosphere varies with the seasonsvaries with the seasons, ,

**solids such as **solids such as dust, ice and saltdust, ice and salt (picked (picked up by wind) up by wind) help the clouds formhelp the clouds form

LayersLayers of the Atmosphere of the Atmosphere TroposphereTroposphere -- 0-10 km ( -- 0-10 km (closest to Earthclosest to Earth)) Tropo – means “Changing”Tropo – means “Changing”We breath this part, planes fly hereWe breath this part, planes fly hereContains the most water vaporContains the most water vaporWeather occurs, Most pollution is foundWeather occurs, Most pollution is found MOST DENSEMOST DENSEThe THINNESTThe THINNESTAt the top ~temp. lower to -60 CAt the top ~temp. lower to -60 C

StratosphereStratosphere -- -- 10-50 km10-50 kmStrato- means “spread out”Strato- means “spread out”Made of conc. ozone which Made of conc. ozone which

absorbs UV radiationabsorbs UV radiationOzone layer at about Ozone layer at about 25 km25 kmGets heated ( up to 0 C from Gets heated ( up to 0 C from

-60)-60)Ozone absorbs harmful rays Ozone absorbs harmful rays

from Sun, and converts to from Sun, and converts to HeatHeat

MesosphereMesosphere -- -- 50-80 km 50-80 km Meso- means “middle Meso- means “middle layer”layer”

Temperature decreases (-40 Temperature decreases (-40 to -80 C at top)to -80 C at top)

Protects Earth from Protects Earth from meteoroids.meteoroids.

Ozone (OOzone (O33)) Ground-level ozone is an Ground-level ozone is an

air pollutant air pollutant

*harmful effects on the respiratory *harmful effects on the respiratory systems of animalssystems of animals

Ozone in the Ozone in the upper atmosphere filters upper atmosphere filters potentially damaging ultraviolet lightpotentially damaging ultraviolet light from from reaching the reaching the Earth's surface. Earth's surface.

ExosphereExosphere – 400+ km – 400+ km ((outermost layeroutermost layer))Exo- means “Outer”Exo- means “Outer”Helium and HydrogenHelium and HydrogenNo clear outer boundaryNo clear outer boundarySatellites found hereSatellites found here

ThermosphereThermosphere -- -- 100-400 km100-400 kmThermo- means heatThermo- means heatVery thin layer, solar radiation Very thin layer, solar radiation absorbedabsorbedContains “Ionosphere”Contains “Ionosphere”Temperature increases (-80 to Temperature increases (-80 to 1800 C at the top)1800 C at the top)Aurora Borealis (Northern Lights) Aurora Borealis (Northern Lights) located here.located here.

http://vimeo.com/16917950

Visible Visible Light and Light and

some some Infrared Infrared

get get throughthrough

But that’s But that’s NOT all!!!NOT all!!!

images are courtesy of Windows to the Universe, http://www.windows.ucar.edu

So Do Radio Waves!!!!!So Do Radio Waves!!!!!

Why is the sky blue?Why is the sky blue?

Transmitted light (from sun, light bulbs, fire etc…) is Transmitted light (from sun, light bulbs, fire etc…) is made of a made of a spectrum of colors – looks whitespectrum of colors – looks white

--Light moves through air --it scatters in all directions--Light moves through air --it scatters in all directions--Longest wavelengths of light = --Longest wavelengths of light = red/orangered/orange Shortest wavelengths = Shortest wavelengths = blue/violetsblue/violets ((shorter wavelengths scatter the most lightshorter wavelengths scatter the most light) ) --Since --Since blue rays scatter the most, blue rays scatter the most,

they reach our eyes from all they reach our eyes from all directions anddirections and we see more we see more blue than any other colorblue than any other color

Atmospheric gases scatter blue light more than other wavelengths, giving the Earth a blue halo when seen from space.

What Makes a What Makes a Red Sunset? Red Sunset?

light has more light has more atmosphere to pass atmosphere to pass throughthrough to get to our to get to our eyes, only the strong eyes, only the strong red lightred light can make it. can make it.

PropertiesProperties of the Atmosphere of the Atmosphere 1.1. Temperature Temperature -- --measures measures

how fast molecules are how fast molecules are movingmoving (particles in any (particles in any material = random motion)material = random motion)

----higher the temp of higher the temp of material/faster particles are material/faster particles are movingmoving

Temperature inversion:Temperature inversion:

When warm air is on top of When warm air is on top of cooler aircooler air

-lack of thermal -lack of thermal energyenergy

-smoke, fog, pollution-smoke, fog, pollution

Conduction Conduction

heat transfer heat transfer through matterthrough matter.. Atoms or molecules Atoms or molecules must touch each othermust touch each other..

Type of heat transfer in Type of heat transfer in solidssolids. .

MetalsMetals conduct heat well. conduct heat well. Air is notAir is not a good a good conductor of heat. conductor of heat.

For example, a spoon in a cup of For example, a spoon in a cup of hot soup becomes warmer because hot soup becomes warmer because the heat from the soup is conducted the heat from the soup is conducted along the spoonalong the spoon..

Convection Convection

heat transfer by heat transfer by the movement of mass from one the movement of mass from one place to another. place to another.

Can take place only in Can take place only in liquidsliquids and and gasesgases . . Convection occurs when areas Convection occurs when areas of cool dense of cool dense

molecules and warmer less dense molecules move molecules and warmer less dense molecules move near each other.near each other.

The heat moves with the fluid in a The heat moves with the fluid in a circular pattern because when areas circular pattern because when areas of cool dense molecules are warmed, of cool dense molecules are warmed, they become less dense and rise. they become less dense and rise. When areas of warm less dense When areas of warm less dense molecules move into cooler areas of molecules move into cooler areas of molecules, they becomes more dense molecules, they becomes more dense and falls.and falls.

Examples: movement of plate, ocean currents, home furnace heating & circulating air

Radiation Radiation

Radiation is Radiation is electromagnetic waves that directly electromagnetic waves that directly transport ENERGYtransport ENERGY through space. through space.

SunlightSunlight is a form of radiation. is a form of radiation. Radiation is the only way heat Radiation is the only way heat is transferred (can is transferred (can

move)move) through the relative emptiness of space. through the relative emptiness of space. Radiation Radiation does not heat air directlydoes not heat air directly as it travels as it travels

through the atmosphere from the sun.through the atmosphere from the sun. AirAir is heated is heated by by reradiatedreradiated waves of molecules on waves of molecules on

the surface of the earth that absorb energy from the the surface of the earth that absorb energy from the sun.sun.

Conduction/Convection/RadiationConduction/Convection/Radiation

DrawDraw

http://www.wisc-online.com/objects/index_tj.asp?objID=SCE304

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2.2. Air pressure Air pressure Air has a Air has a mass that is constantlymass that is constantly

pushing down on us -due to gravitypushing down on us -due to gravity

Pressure is the Pressure is the greatest on the Earths surfacegreatest on the Earths surface and and will decrease as the mass of air above you will decrease as the mass of air above you decreasesdecreases

** Relationship between Air pressure and Temperature** Relationship between Air pressure and Temperature

TemperatureTemperature Air PressureAir Pressure Density of AirDensity of Air

IncreasesIncreases IncreasesIncreases DecreasesDecreases

DecreasesDecreases DecreasesDecreases increasesincreases

3.3. Humidity Humidity

----the amount of water vapor in the airthe amount of water vapor in the air, , -- 2 ways to express water vapor content in atmosphere:-- 2 ways to express water vapor content in atmosphere:a) dew point: a) dew point: the temp. in which condensation occursthe temp. in which condensation occursb) relative humidity: b) relative humidity: the amount of water the air at a the amount of water the air at a

given temp. can holdgiven temp. can hold, expressed in % , expressed in % Ex. relative humidity is 50% Ex. relative humidity is 50%

- - air contains 50% of the air contains 50% of the water vapor needed water vapor needed for air to be saturatedfor air to be saturated

WindWind

– – moving airmoving air --created by an --created by an

imbalance between imbalance between warm (less dense) & warm (less dense) & cool (more dense)cool (more dense) air-creates high/low air-creates high/low pressure areaspressure areas

--wind speed --wind speed increasesincreases with with heightheight in atmospherein atmosphere

CloudsCloudsWhy clouds are white?Why clouds are white?Water droplets in clouds have Water droplets in clouds have many surfaces to many surfaces to

reflect lightreflect light, and scatter almost all the light and , and scatter almost all the light and look white even though clouds are nearly look white even though clouds are nearly transparenttransparent

Ex. Ex. Root-beer foamRoot-beer foam, salt/sugar crystal, salt/sugar crystalfoam - foam - whitewhite / liquid – / liquid –coloredcolored*walls of the *walls of the foam bubbles are so thinfoam bubbles are so thin – reflect light – reflect light while light is while light is absorbed by the liquidabsorbed by the liquid

Cloud FormationCloud Formation::

1.1. Warm, humid air risesWarm, humid air rises2.2. Air cools, Air cools, due to convection due to convection

currentscurrents3.3. Dew point is reachedDew point is reached4.4. Water droplets form around a Water droplets form around a

small particle of dust/saltsmall particle of dust/salt 5.5. The salt, dust, or ice at the center of the droplet is The salt, dust, or ice at the center of the droplet is

called: called: condensation nucleuscondensation nucleus6.6. If the air mass rises very rapidly, If the air mass rises very rapidly, rain occursrain occurs

**This can take place at **This can take place at many different altitudesmany different altitudes, , which makes which makes different types of cloudsdifferent types of clouds

****If it takes place at ground level = fogIf it takes place at ground level = fog

Types of CloudsTypes of Clouds

Name of cloudName of cloud Height of cloudHeight of cloud

Cirro-Cirro- Above 6000mAbove 6000m

Alto-Alto- 2000-6000m2000-6000m

Strato-Strato- Below 2000mBelow 2000m

3 Main groups

Luke Howard – 1803

“Man that named the clouds”

Each group is then described by shape:

Descriptive nameDescriptive name ShapeShape

Cirrus Cirrus Curls of hairCurls of hair Wispy stringy cloudsWispy stringy clouds

Cumulus Cumulus Heap Heap Puffy, lumpyPuffy, lumpy

Stratus Stratus Layer Layer Sheets of cloudsSheets of clouds

Nimbus Nimbus Rain Rain Low gray rain cloudsLow gray rain clouds

Describe these clouds:Describe these clouds:

Height and shapeHeight and shape are combined to form are combined to form name of clouds:name of clouds:

1.1. puffy clouds at 2000-6000m:puffy clouds at 2000-6000m:

2.2. low gray clouds below 2000m:low gray clouds below 2000m:

3.3. above 6000m, wispy clouds:above 6000m, wispy clouds:

1. Altocumulus1. Altocumulus

2. Nimbostratus2. Nimbostratus

3. Cirrus3. Cirrus

Vertical Developing CloudsVertical Developing Clouds Air of cumulus cloud = Air of cumulus cloud =

unstableunstable Cloud warmer than Cloud warmer than

surrounding airsurrounding air

It will continue to grow upwardIt will continue to grow upward Large, puffy rain clouds = Large, puffy rain clouds =

CumulonimbusCumulonimbus

Can reach past the troposphereCan reach past the troposphere Result in Result in super-cell super-cell

thunderstormsthunderstorms, severe , severe weather weather

Draw:Draw:

PrecipitationPrecipitation

----All forms of weather that All forms of weather that fall from clouds to groundfall from clouds to ground

Four Main types: Four Main types: Rain,Snow,Sleet, & HailRain,Snow,Sleet, & Hail

Formation of precipitation:Formation of precipitation:

CoalescenceCoalescence – warm cloud droplets collide – warm cloud droplets collide and form larger droplets and form larger droplets which which are too heavy are too heavy to stay aloftto stay aloft

= resulting in = resulting in RainRain

Types of Precipitation Types of Precipitation Remember the water cycle song :o)Remember the water cycle song :o)

Snow = Snow = in cold clouds ice in cold clouds ice crystals are formedcrystals are formed

Sleet = convective currents Sleet = convective currents carry droplets carry droplets up/down up/down through freezing & through freezing & nonfreezing airnonfreezing air, forming , forming ice pelletsice pellets

Hail = Hail = if up/down motion is if up/down motion is extremely strong & takes extremely strong & takes place over long stretches place over long stretches of atmosphereof atmosphere, forms , forms very large ice pelletsvery large ice pellets

The EndThe End

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