The Atmosphere http://chrismaddencartoons.wordpress.com/category/environment/pollution/

Atmospheric Composition Grab a handful of air… Earth’s atmosphere is mostly nitrogen and oxygen N2 (78%) and O2 (21%) make up 99% of the atmosphere Less than 1% is other gases (e.g., argon, carbon dioxide, methane, water vapor), dust

Earth’s Atmosphere

Key Atmospheric Gases (Small but Mighty) Water (H2O) Amount changes constantly, 0-4% Source of clouds and precipitation Absorbs heat from Earth and some solar energy Ozone (O3) Very small amount (>0.01%) Absorbs harmful UV radiation Protects our skin from sun damage Carbon dioxide (CO2) 0.03% Absorbs heat, contributes to global warming Methane (CH4) Extremely small amount (>0.001%)

Human Influences on Atmosphere (just a few examples) Chloroflorocarbons (CFCs -- aerosols, refrigerants, some Styrofoam) destroy the ozone layer CO2 emissions from cars contribute to global warming Air pollution causes human health problems asthma lung cancer respiratory illness heart disease

Primary Pollutants

Atmospheric structure The atmosphere is made up of 4 main layers, defined by temperature and composition: Troposphere Stratosphere Mesosphere Thermosphere

Troposphere Sphere of weather Thinnest layer of the atmosphere Temperatures decrease with height (Have you ever been to the top of a mountain?) Greenhouse effect Height: 0-12 km

Snowy Mountaintops Contrast with Warmer Snow-Free Lowlands

Stratosphere Temperatures increase Ozone layer Long distance airplane flights (lower part) Height: 12-50 km

Mesosphere Temperatures decrease (as low as -90◦ C) Meteors burn up Height: 50-80 km

Thermosphere Temperatures increase (O2 and N2 absorb solar radiation) Northern lights, satellites, space shuttle 80 km to…? (no defined upper limit)

Do you mean Temperature… or Heat? Temperature: measurement of the kinetic energy (energy of motion) of atoms or molecules Faster motion = higher temp. Heat: transfer of energy from one object to another because of a difference in temperature Heat flows from higher to lower temp. Heat fuels the weather, and temperature measures it!

Pressure-Density-Temperature Relationship Air pressure: weight of the air pressing on you gases at the top press down on the ones below Density: measure of particles in a given space More particles = higher density Temperature: proportional to pressure, inversely proportional to density Atmospheric Relationships As T ↑ , P ↑ As T ↓ , P ↓ As T ↑ , D ↓ As T ↓ , D ↑ T = Temperature P = Pressure D = Density ↑ = Increases ↓ = Decreases

Air Pressure v. Altitude Altitude: measure of distance “up” in the air As altitude ↑, pressure ↓ (and therefore T ↓) Why is it harder to breathe at the top of a mountain? Components of the atmosphere

Write your summary box!