1. EARTH ’ S ATMOSPHERE SOL 6.6 a,b,c,d

2. EARTH ’ S ATMOSPHERE EARTH ’ S 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 atmosphere is a THIN layer of gases surrounding our planet

3. 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 (CO 2 ) ~Argon (Ar) ~Water Vapor (H 2 O) ~Many More!

4. 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

5. The FOUR Main Layers of Earth ’ s Atmosphere TROPOSPHERE: Weather happens here! (0-10km) STRATOSPHERE: Ozone layer Ozone 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)

6. Earth Thermosphere Mesosphere Stratosphere Troposphere TROPOSPHERE In a sample of air from the TROPOSPHERE containing 100 molecules, how many would be: nitrogen ___ oxygen ___ other ___ other ___ STRATOSPHERE: In the same size sample from the STRATOSPHERE: nitrogen 20 oxygen 5_ other _0_ other _0_ MESOSPHERE: nitrogen _5_ oxygen _1_ other _0_ other _0_ THERMOSPHERE: THERMOSPHERE: nitrogen _2_ oxygen _0_ other _0_ other _0_ Jet Stream (wind current) Ozone layer 7821 1

7. 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 ____________________ ____________________ ____ (3) In which layer would you feel the LEAST air pressure, and WHY? ____________ because _________________________________________ ________________________

8. 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.

9. AIR PRESSURE & ALTITUDE ALTITUDE-distance above sea level ALTITUDE-distance above sea level ~Air is LESS DENSE the higher you go on Earth. higher you go on Earth. (*there is more space (*there is more space between the molecules) between the molecules) So…Air pressure DECREASES as altitude INCREASES In other words, the higher you go, the less air pressure there is. (Fewer air molecules pressing the less air pressure there is. (Fewer air molecules pressing down on you) down on you)      Density of air molecules at 8km ABOVE sea level Density of air molecules AT sea level

10. 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 inhale 3) Each time you breathe, which gas do you 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 travel 5) As your altitude increases on Earth (as you travel higher), what happens to the air pressure? higher), what happens to the air pressure?

11. In which layer of the atmosphere would air be the MOST dense? ________________ In which layer of the atmosphere would air be the LEAST dense? _____________________ TROPOSPHERE THERMOSPHERE On the next page in your notebook, draw lines to divide your paper into four equal sections. Label each section with the names of the layers of the atmosphere, starting with the _______________ _ at the bottom (nearest Earth). Color a strip at the bottom of the page green to represent Earth. TROPOSPHERE Jet Stream Draw the items you see here to show what is found in each layer. ozone layer

12. LOW temperature & pressure HIGH temperature & pressure ~TROPOSPHERE~ The layer closest to Earth ~All of Earth ’ s WEATHER happens in this layer! COLDER here- where the air is less dense WARMER here - where the air is more dense ~As your altitude in the troposphere INCREASES, the air temperature DECREASES! storm cloud rain

13. WATER IN THE ATMOSPHERE  Because of evaporation & transpiration, there is ALWAYS water vapor in the air.  HUMIDITY- the AMOUNT of WATER VAPOR in the AIR  WARM air can hold MORE water vapor than COOL air  PSYCHROMETER-tool used to MEASURE humidity

14. HOW CLOUDS FORM  WATER VAPOR RISES into the atmosphere (evaporation & transpiration)  The drops or crystals cling to particles of dust, salt, & smoke in the air to form CLOUDS  Drops COOL and CONDENSE (drops collect together)

15. CLOUD TYPES  CUMULUS - Look like fluffy, rounded piles of cotton. FAIR WEATHER  STRATUS - spread out…usually cover all or most of the sky like a blanket  CIRRUS -Wispy,feathery, very high up…made of ice crystals THERE ARE 3 MAIN CLOUD TYPES

16. CLOUD PREFIXES CAN BE ADDED TO THE BEGINNING OF A CLOUD NAME to DESCRIBE the kind of cloud you are looking at. EXAMPLES:  CUMULONIMBUS - tall, fluffy rain clouds  NIMBOSTRATUS - flat, layered rain clouds  ALTOSTRATUS - high, flat, layered clouds  ALTO - high  CIRRO - very high  NIMBO or NIMBUS -rain  STRATO -flat or layered  CUMULO - tall & fluffy