Chapter 15The Atmosphere Mr. Manskopf Notes Also At http://www.manskopf.com
The air we breathe and all the weather we see is contained in the lowest 1% of the Earth’s atmosphere.
Chapter 15 Big Idea Our atmosphere is critical to all life on Earth. Human actions have a great impact on our atmosphere.
Section: Earth’s Atmosphere • Describe the properties of the atmosphere. • Identify the main layers of the atmosphere. • Explain how heat is transferred in the atmosphere
What is the Atmosphere? Thin layer of gases surrounding our planet • Skin of apple thin • We live at bottom • Air is a fluid • Why don’t gases fly away into space?
Why is it important? Earth’s atmosphere makes life on Earth possible. • Protects us from sun’s rays. • Provides vital gases like oxygen, nitrogen and carbon dioxide. • Keeps temperature comfortable • Allows water to circulate around planet. • Protects us from meteoroids.
The Air Around YouWeather Weather is the state of the atmosphere at any one moment.
What is it made of? Earth’s Atmosphere is made of: • 78 % Nitrogen • 21% Oxygen • 1% a bunch of others (Argon, Carbon Dioxide, Water Vapor…)
Water in the Air Relative Humidity • Amount of water vapor in the air • Changes constantly • Warm Air = More Moisture • Condensation = Clouds
Cloud Formation http://youtu.be/NiCSk1zxMEs
Air temperature Changes vertically and horizontally on Earth • Why is it cold on top of mountains? • Why are the tropics warmer than the polar regions?
Air Pressure The force of a column of air pushing down on an area Where is air pressure greater, sea level or top of a mountain? Why are airplanes pressurized?
Barometers An instrument used to measure air pressure.
Air pressure Differences in air pressure is going to help us understand: • Wind • Cloud formation • Tornadoes • Almost all weather
Four Main Layers of Atmosphere The four main layers of our atmosphere are classified according to changes in temperature. • Troposphere • Stratosphere • Mesosphere • Thermosphere
The Troposphere The Troposphere: • Inner most layer (0 to 12km) • Where all weather occurs • The temperature decreases to -60 degrees at top.
The Troposphere Clouds, rain, snow and all precipitation occur here. Air Pressure and Temperature drop quickly in troposphere.
Stratosphere Layer above troposphere where atmosphere warms slightly Ozone layer located there blocks out harmful UV Rays
Mesosphere • “Middle Layer” • Temperatures reach -90 degrees Celsius • Where meteoroids burn up in atmosphere
Thermosphere • “Thermo” means heat • Air is only 0.0001 % as dense as sea level • Air slowly blends into outer space • Hottest layer of atmosphere because energy from the sun strikes it first
Heat Transfer in the Troposphere 1) Radiation: The transfer of energy through space, such as heat from the sun to Earth’s atmosphere