The Atmosphere 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 Earths surface? Air is thinner What is the temperature like? cooler Where does outer space start? Above exosphere Will the jumper feel the wind rushing against him as he starts his jump? Feels wind as he enters troposphere After the video- Discuss Why is he in a space suit? What are the air and the temperature like 24 miles above Earths surface? Was he in outer space? When did his space suit start flapping in the wind? Felix jumped 24 miles above sea level Wind started about 16 up miles- why? 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 0- 4% 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 Earths 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 Earths 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 Surface to 6 miles Where airplanes usually fly Most atmospheric gases found here Stratosphere 6 miles to 30 miles above Weather balloons here Ozone layer here 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 Middle layer from 30 to 50 miles above Where meteors burn up Coldest part of the atmosphereB_p4I 2013 Russian meteorite video Thermosphere 50 to 400 miles above surface 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 Earths magnetic field in the thermosphere Exosphere 400 to 600 miles above surface Very few air molecules 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 hitters 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 Suns 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 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 earths surface and increase skin cancer rates Intro to Lab ts/science/virtual_labs/ES14/ES14.htmlts/science/virtual_labs/ES14/ES14.htmlts/science/virtual_labs/ES14/ES14.html What is the most abundant gas in the atmosphere? Nitrogen (78%) then Oxygen (21%)