EARTH’S ATMOSPHERESOL 6.6 a,b,c,d

EARTHEARTH’’S ATMOSPHERES ATMOSPHERE

~PROVIDES OXYGEN & OTHER GASES needed by ALL living things

~PROTECTS LIFE ON EARTH from the sun’s dangerous radiation & too much heat

~KEEPS US WARM by trapping some heat from the sun

~PROTECTS EARTH from being hit by most meteoroids

~Earth’s ~Earth’s atmosphereatmosphere is is a a THINTHIN layer of gases layer of gases surrounding our planetsurrounding our planet

COMPOSITION OF THE ATMOSPHERE

NITROGEN (78%)~needed for growth & to repair body cells

OXYGEN (21%)~needed by most living things to exist

OTHER GASES (1%)~Carbon Dioxide (CO2)~Argon (Ar)~Water Vapor (H2O)~Many More!

The Atmosphere Can be Polluted by…

· NATURAL EVENTS

~ Naturally-caused Forest Fires

(usually from lightning strikes)

~ Volcanic Eruptions

· HUMAN ACTIVITY

~ Exhaust fumes from cars, lawnmowers, airplanes, factories, etc.

~ Human created forest fires

The FOUR Main Layers of The FOUR Main Layers of EarthEarth’’s Atmospheres Atmosphere

TROPOSPHERE: Weather happens here! (0-10km)

STRATOSPHERE: Ozone layerOzone layer -shields us from harmful ultraviolet radiation (10-50km)

MESOSPHERE: Meteoroids burn up here(50-80km)

THERMOSPHERE: Satellites orbit here (above 80km)

HOTTEST

COLDEST

Northern Lights(Aurora Borealis)

Earth

Thermosphere

Mesosphere

Stratosphere

Troposphere

In a sample of air from the TROPOSPHERETROPOSPHERE

containing 100 molecules, how many

would be:nitrogen ___ oxygen ___

other ___other ___

In the same size sample from the STRATOSPHERESTRATOSPHERE::

nitrogen 20 oxygen 5_

other other _0__0_

MESOSPHEREMESOSPHERE::nitrogen _5_ oxygen _1_

other other _0__0_

THERMOSPHERETHERMOSPHERE:: nitrogen _2_ oxygen

_0_ other other _0__0_

Jet Stream

(wind current)

Ozone layer

78 211

Earth

Thermosphere

Mesosphere

Stratosphere

Troposphere

From the diagram you have just made, answer the following questions:

(1) In which layer of the

atmosphere are most of

the air molecules located? ____________

(2) In which layer would you feel the MOST air pressure, & WHY?

____________ because ____________ because ________________________________________________________________________________________

(3) In which layer would you feel the LEAST air pressure, and WHY? ____________ because _________________________________________________________________

(3) In which layer would you feel the LEAST air pressure, and WHY? ____________ because _________________________________________________________________

AIR PRESSURE

What IS air pressure?

AIR PRESSURE is the WEIGHT OF AIR PRESSING DOWN ON AN AREA.

Why don’t we feel air pressing down on us?

Because air molecules are pushing on us in ALL directions…so it feels EQUAL.

AIR PRESSURE & ALTITUDEAIR PRESSURE & ALTITUDE ALTITUDEALTITUDE-distance above sea level-distance above sea level

~Air is ~Air is LESS DENSELESS DENSE the the higherhigher you go on Earth. you go on Earth. (*there is more space (*there is more space

between the molecules)between the molecules)

So…Air So…Air pressurepressure DECREASES as altitude INCREASES DECREASES as altitude INCREASES

In other words, the higher you go,In other words, the higher you go, the less air pressure there is. (Fewer air the less air pressure there is. (Fewer air molecules molecules pressingpressing

down on you)down on you)

Density of air molecules at 8kmABOVE sea level

Density of air molecules AT sea level

QUIZ!QUIZ! 1) The ______ is a thin layer of gases that 1) The ______ is a thin layer of gases that

surrounds our planet.surrounds our planet. 2) Name one way the atmosphere is important to 2) Name one way the atmosphere is important to

Earth.Earth. 3) Each time you breathe, which gas do you 3) Each time you breathe, which gas do you inhale inhale

the most of? ____________the most of? ____________ 4) What is air pressure?4) What is air pressure? 5) As your altitude increases on Earth (as you 5) As your altitude increases on Earth (as you travel travel

higher), what happens to the air pressure?higher), what happens to the air pressure?