The Atmosphere

Model it  Draw a model of what you think the Earth’s atmosphere looks like on your notes. ?

Outline  What is it?  What is it made of?  Why do we need it?  What are the different layers of it like?

Introduction Assess prior knowledge  Make some predictions about the atmosphere, then watch the following video. –What is the air like 24 miles above Earth’s surface? –What is the temperature like? –Where does outer space start? –Will the jumper feel the “wind” rushing against him as he starts his jump? –

After the video- Discuss Why is he in a space suit? –What are the air and the temperature like 24 miles above Earth’s surface? –Why does the balloon get larger the higher it goes? –Was he in “outer space”? –Does his space suit start flapping in the wind right away?

 Felix jumped 24 miles above sea level  “Wind” started about 16 up miles- why?

Expected Records He broke 3

What is the atmosphere?  A blanket of gases that surround Earth and are held in place by gravitational forces.

What is the atmosphere made of?  The atmosphere is made of solids, liquids, and gases.  Gases: –78% Nitrogen (N) –21% Oxygen (O) –1% trace gases including- Argon (Ar), Carbon Dioxide (CO 2 ), Neon (Ne), Helium (He), Hydrogen (H), and Ozone (O 3 )

Do you think the atmosphere was the same 4.6 billion years ago? Just formed Earth: Like Earth, the hydrogen (H 2 ) and helium (He) were very warm. These molecules of gas moved so fast they escaped Earth's gravity and eventually all drifted off into space. Young Earth: Volcanoes released gases H 2 O (water) as steam, carbon dixoide (CO 2 ), and ammonia (NH 3 ). Carbon dioxide dissolved in seawater. Simple bacteria thrived on sunlight and CO 2. By-product is oxygen (O 2 ).

As plants evolved, so did our atmosphere Current Earth: Plants and animals thrive in balance. Plants take in carbon dioxide (CO 2 ) and give off oxygen (O 2 ). Animals take in oxygen (O 2 ) and give off CO 2. Burning stuff also gives off CO 2.

Liquids in the atmosphere  Water vapor –Varies with humidity levels

Solids in the atmosphere –Dust –Pollen

Why do we need an atmosphere?  What would Earth be like without one?

1. Contains air for respiration and photosynthesis

2. Controls Earth’s temperature

 But too much atmosphere can be bad! –It makes Venus the hottest planet in the Solar System (Average temp: 800+ degrees F)

3. Protects us from: –Harmful sun rays – UV (ultraviolet) –Meteors, asteroids, etc.

What are the different layers of the atmosphere?

Layers  5 layers starting at Earth’s surface and going up: –Troposphere (lowest) –Stratosphere –Mesosphere –Thermosphere –Exosphere (highest)

Make up an acronym to remember the layers  TSMTE –Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere  The Starving Monkey Tries Eggs

 Troposphere –Altitude (Height): surface to 6 miles –Air pressure: decreases –Temperature: decreases –Phenomenon: most gases found here, planes fly here

 Stratosphere –Altitude (Height): 6-30 miles –Air pressure: decreases –Temperature: increases –Phenomenon: Weather balloons here, ozone layer here youtube.co m/watch?v =aXzs46aE JLg

Ozone Layer  Made of oxygen (O 3 )  It absorbs most of the ultra violet radiation from the sun (UV rays)

 The ozone protects us from skin cancer  The ozone layer has been damaged by CFCs (chlorofluorocarbons)

 Mesosphere –Altitude (Height): miles –Air pressure: decreases –Temperature: decreases (coldest layer) –Phenomenon: Where meteors burn up com/watch?v=Y66O HiB_p4I 2013 Russian meteorite video

 Thermosphere –Altitude (Height): miles –Air pressure: decreases –Temperature: increases –Phenomenon: X-ray and UV energy is absorbed here, causing high temperatures, space shuttle flew here, International Space station orbits in this layer, Northern lights happen here

Charged particles from the sun interact with Earth’s magnetic field in the thermosphere

 Exosphere –Altitude (Height): miles –Air pressure: decreases (very few air molecules) –Temperature: decreases –Phenomenon: Boundary with “outer space”

Atmospheric Pressure  As you increase in altitude, air pressure decreases. Water bottles are crushed as a plane descends due to increasing air pressure

Why is Denver considered a “hitter’s park” more than other baseball stadiums? Fly balls typically travel about 5% farther at Coors than at Fenway, all other things equal. Therefore a 380 ft drive at Fenway will travel nearly 400 ft at Coors Field. Lower air density than other fields.

Atmospheric Temperatures  Some layers easily absorb the Sun’s energy, while others do not.  Temperatures vary in each layer.

Review

Name the Layers  Name the correct order of the layers of the atmosphere starting from Earth. –Troposphere –Stratosphere –Mesosphere –Thermosphere –Exosphere

What is the most abundant gas in the atmosphere? Nitrogen (78%) then Oxygen (21%)

 Why do we need our atmosphere? Provides air for respiration and photosynthesis Controls our temperature Protects us from harmful sun rays and meteors

 Why is it harder to breathe when you climb tall mountains? –Less air pressure, so there are fewer oxygen molecules

 What happens if our ozone layer disappears? –More harmful rays can reach earth’s surface and increase skin cancer rates

Model it  Modify your original model of what you think the Earth’s atmosphere looks like, include any new information you learned. ?

Intro to Lab  ts/science/virtual_labs/ES14/ES14.html ts/science/virtual_labs/ES14/ES14.html ts/science/virtual_labs/ES14/ES14.html