The AtmosphereThe Atmosphere

Earth Science Earth Science

Grade 8Grade 8

The Air That We BreatheThe Air That We Breathe

• Gases:– Nitrogen = 71%– Oxygen = 21%

– Trace gases: Hydrogen, helium, CO2, CO, O3,

– Water vapor-changes from 0% to 4 % depending on the weather

• Liquids: Rain

• Solids: Snow, Sleet, Hail, dust

Water, water,everywhereWater, water,everywhere

• The only compound found as a solid, liquid, and a gas in the atmosphere is

The Layers of the AtmosphereThe Layers of the Atmosphere

• Thermosphere

• Mesosphere

• Stratosphere

• Troposphere

The layers are not very thick when viewed from outer space

The layers are cause by The layers are cause by temperature differences temperature differences

TroposphereTroposphere

• Lowest layer of the atmosphere/ closest to the planet

• Where we live and breathe

• Where most of the gases are located

• Where the weather takes place

StratosphereStratosphere

• Where the planes fly to avoid the weather

• Home of the ozone layer

OZONE LAYEROZONE LAYER

• Layer of protection located within the stratosphere

• The ozone molecules collect the UV Rays coming from the SUN.

• Without it the temperature on the planet would be exceptionally hot…maybe too hot for life to flourish.

MesosphereMesosphere

• Coldest layer

• (That’s it, it’s very boring)

ThermosphereThermosphere

• First layer of protection from the Sun

• Absorbs some of the sun’s UV rays

• Blends into space

• Where the satellites fly

• Where the ionosphere is located

IonosphereIonosphere

• A layer of charged particles (ions) floating around the atmosphere.

• When you send radio waves into the atmosphere, they hit the ions and bounce back to the earth. That is how you receive radio and television signals.

Radio WavesRadio Waves

Without the AtmosphereWithout the Atmosphere

• The energy from the Sun would heat the planet so much that we would not be able to live here.

• The meteors coming from space would not burn up and the Earth’s surface would look like the moon.

• We would not have any types of plants, which would mean that there would not be any oxygen on the planet.

Mercury has a Mercury has a very thin very thin

atmosphereatmosphere

The Moon does not have an atmosphere

When did the Atmosphere appear?When did the Atmosphere appear?

• The Earth did not always have an atmosphere.

• Erupting volcanoes early in the Earth’s history caused gases to be released and eventually collected into the atmosphere as we know it.

Without the atmosphereWithout the atmosphere

• The energy from the Sun would heat the planet so much that we would not be able to live there.

• The meteors coming from space would not burn up and the face of the planet would look very different.

• We would not have any types of plants, which would mean that there would not e any oxygen on the planet.

Shooting StarsShooting Stars

• Meteors from space sometime enter our atmosphere. If they do, most of the material will burn up as they rocket towards Earth. This is due to the friction of the rock rubbing against the gases in the atmosphere.

• If they do make it completely through the atmosphere, they land as meteorites on the land or in the oceans creating craters.

Shooting starsShooting stars

Meteors that do get through leave Meteors that do get through leave craters on the planetcraters on the planet

Barringer Crater in Arizona

Inside view of Barringer Crater

Crater on USA SoilCrater on USA Soil

Air PressureAir Pressure

• Air does have mass.• The air pushes down on us every second of our

lives, so we don’t feel the pressure. • The more atmosphere above you, the more

pressure you feel.• The people who live at sea-level (0ft) have the

most pressure.• The people who live on top of the mountain have

the least amount of pressure.

Air Pressure at different heights Air Pressure at different heights above sea levelabove sea level