Do Now pg 87 Solve this riddle! You can t see me You can t taste me You can t feel me But you need me I kill 7 million people a year But you kill what keeps me clear What am I?
Lesson 15.1 Earth s Atmosphere The air we breathe and all the weather we see is contained in the lowest 1% of the Earth s atmosphere.
Start notes on page 88 Properties of the Atmosphere Composition: 78% nitrogen, 21% oxygen, and 1% other gases Temperature: Varies and location Pressure: In general, air pressure decreases with altitude; can be measured using a barometer. Barometer
Lesson 15.1 Earth s Atmosphere The ratio of water vapor in air to the maximum amount the same air could contain at the same temperature Is affected by temperature and location; in general, warm air holds more water. Relative Humidity When air cools, water vapor may condense to liquid or to ice. Water vapor can only condense on surfaces, such as a petal or a dust particle. Hoarfrost on leaves
Lesson 15.1 Earth s Atmosphere Layers of Atmosphere Did You Know? The stratosphere and mesosphere are cold, but the upper thermosphere can be hotter than 1500 C. Troposphere: 0 11 km; movement of air, weather Stratosphere: 11 50 km; ozone layer, absorbs and scatters UV rays Mesosphere: 50 80 km; meteoroids burn up Thermosphere: 80+ km; disturbances produce aurora borealis
Lesson 15.1 Earth s Atmosphere Heat Transfer in the Troposphere Radiation: The transfer of energy through space, such as heat from the sun to Earth s atmosphere Conduction: The transfer of heat directly between two objects that are in contact Convection: The transfer of heat by the movement of currents within a fluid (liquid or gas)
Lesson 15.1 Earth s Atmosphere Convection Currents Warm air is less dense than cool air. When air near the surface heats up, it rises; as it rises, it cools and then sinks. Rising and sinking fluids generate convection currents. Cause wind and heat to move through the atmosphere
Lesson 15.1 Earth s Atmosphere Air Masses and Fronts Air masses: Large bodies of air with similar properties Fronts: Boundaries between air masses of different properties Warm front Boundary along which a mass of warmer, moister air pushes against a mass of cooler, drier air Can produce light precipitation Cold front Boundary along which a mass of cooler, drier air pushes against a mass of warmer, moister air Can produce heavy precipitation
Lesson 15.2 Pollution of the Atmosphere Air pollution is estimated to cause 2 million premature deaths worldwide every year.
Lesson 15.2 Biomes Sources of Air Pollution Natural processes: Windblown dust, particles in volcanic eruptions, smoke and soot from fire Human sources: Most come directly or indirectly from the burning of fossil fuels. Did You Know? Humans can increase the hazards of natural air pollution. For example, by removing trees, humans expose soil, which can dry out and add to huge dust storms when picked up by wind. Dust storm approaching a U.S. farm during the 1930s
The production and discharge of something, especially gas or radiation Emission
Air Pollution Video 1. Out of 375 days in the year how many were considered polluted forcing people to stay inside? 2. What percent of China s population breaths clean air daily? 3. Where does most of China s smog come from? 4. How does China s air pollution affect us in Florida? 5. Name another place that receives the air from a foreign place. How is that case different? What are the cleanest cities?
Particles in the air lab Materials index card (unlined) or cardboard metric ruler scissors single-hole punch 2 m length of string paper towel petroleum jelly hand lens, magnifying glass, or dissecting microscope Safety Do not direct the points of the scissors toward yourself or others. Use the scissors only as instructed. Wash your hands after completing the procedure. Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Measure, mark, and cut a 4 cm 4 cm square piece of the index card or cardboard. Punch a hole through your square and tie one end of the piece of string to your square through the hole to make an air-trap card. Using a paper towel, cover one side of the square with petroleum jelly. Wipe off your hands immediately afterward. Put away all materials. Use the string to hang your air-trap card in an outdoor location. Record and note the location and briefly describe the surroundings. Collect your square after 24 hours and examine the side with the petroleum jelly using a hand lens, magnifying glass, or dissecting microscope. Take care not to get petroleum jelly on the lens.
Pre-lab questions 1. Record and observe the location of your square Date and Time Location Conditions surrounding the location (weather, traffic, buildings, etc) 2. What do you expect to see when observing your square under magnification, after one full day of hanging in this location?
Article: Charging Toward Cleaner Air in London Why are nitrogen oxides considered harmful to humans? In what way are nitrogen oxides harmful to the environment? Which 6 nations in Europe ranked highest in nitrogen oxide emissions in 2007? List the nations from highest in emissions to the lowest. Which nation ranked higher in nitrogen oxide emissions than Italy, but lower than France? How is Europe addressing the problem of harmful emissions, such as nitrogen oxides? How does the information in Air Pollution affect your answer to the Big Question: How can we ensure everyone has clean air to breathe?