The Air Around You Notes Chapter 1.1 pgs 6-9

Weather Weather – the condition of the Earth’s atmosphere (temp, precipitation, humidity, wind, clouds) at a particular time and place. Weather is different everywhere you go, and it is always changing! Climate – the average conditions of the Earth’s atmosphere (temp, precipitation, humidity, wind, clouds) in an area

Atmosphere Atmosphere – the envelope of gases that surround and protect the Earth. The atmosphere appears to be very thick from our perspective, but is actually quite thin. Atmosphere = avg 500 km Earth’s radius (core to surface) = avg 6,000 km

Atmosphere Composition of Atmosphere Nitrogen (N2) – 78% Oxygen (O2) – 21% Carbon Dioxide (CO2) – 0.038% Plus other trace gases gases in very small amounts (argon, neon, helium, methane, krypton, hydrogen) Can still have an important effect on Earth’s climate and human health! Water vapor – water is gaseous form Solid & liquid particles of dust, smoke, salt, and other chemicals

Composition of Atmosphere Nitrogen (N2) – important to plant growth Oxygen (O2) – important to animal life, we need to breathe oxygen! Ozone (O3) – a form of oxygen Pollutant in troposphere (poisonous) Ozone Layer in stratosphere traps heat and protects against ultraviolet solar radiation

Composition of Atmosphere Carbon Dioxide (CO2) important to plants, necessary for photosynthesis Traps heat in atmosphere Too much CO2 is driving rapid climate change (global warming) Water Vapor (H2O) – water in gas form Causes clouds and precipitation (rain, snow) Steam – tiny liquid water drops in the air

Composition of Atmosphere Trace Gases – tiny amounts of different gases, but can still be important Methane (0.00015%) – a powerful “greenhouse gas” that traps heat in the atmosphere Particles – tiny solid and liquid particles of dust, smoke, salt, and other chemicals Can be serious pollutants Can be added to atmosphere by nature or by man

Atmosphere Our atmosphere is important because Provides oxygen, and other necessary gases, for life to survive Traps heat to keep us from freezing, and to keep water liquid Protects the surface from meteors and dangerous solar radiation