Presentation on theme: "Book I, Chapter 1 “The Atmosphere”"— Presentation transcript:
1 Book I, Chapter 1 “The Atmosphere” Section 1, pages 4-9“Characteristics of the Atmosphere”
2 Atmosphere – A mixture of gases that surrounds the Earth. Composition of the Atmosphere:Gases:78% Nitrogen21% Oxygen1% Argon, CO2,Water Vapor &other GasesSmall amts. of Solids& Liquids (ex. dust)
3 Air Pressure – A measure of the force with which the molecules push on a surface. What causes air pressure?Air pressure is caused as gravity pulls molecules in the atmosphere toward the Earth.
4 Example of Air Pressure Popping of your ears. As an airplane goes up and down at different elevations the air pressure outside your ears changes, but the pressure inside your ears stays the same.
5 Altitude – The height of an object above the Earth’s surface. Gravity pulls the molecules toward the Earth’s surface.The farther away from the Earth’s surface, the pressure decreases.Altitude = PressureUp Down
6 Layers of the Atmosphere – 4 layers based on temperature. 1. Troposphere (tropo means “change”)Lowest layer of atmosphere (closest to Earth)Weather take place hereBegins at surface of Earth & extends out 4-10 milesLayer where we live also known as lower atmosphereTemperature decreases with height
7 2. Stratosphere (strato means “layer”) Above the troposphereAir very thin w/ little moistureExtends miles above Earth’s surfaceTemperature rises w/ increasing altitude, but stillwell below freezingOzone layer located hereOzone – made of 3 oxygen atoms & absorbs solar energy in form of UV rays in the ozone layer. This warms the air & protects life on the Earth’s surface.
8 3. Mesosphere – (meso means “middle”) Above the stratosphereAbout miles above surface of the EarthColdest layer w/ temps as low as -93º CAir is thin and molecules are very far apartStrong wind storms4. Thermosphere – (thermo means “heat”)The uppermost layerFrom miles above surface of the EarthTemp increases w/ height as high as 1,700º CDoesn’t feel hot b/c air particles are too far apart for energy to be transferred
9 Air Temperature & Altitude Air temperatures change as altitude increases.Temperature changes mainly from the way solar energy is absorbed as it moves downward through the atmosphere.Some gases in the atmosphere absorb solar energy more than others, and warm the atmosphere.
10 What does air pressure, temperature, and layers of the atmosphere have to do with weather? 1. Areas of high pressure usually have clear skies, and areas of low pressure usually have clouds. 2. Our weather takes place in the lower layer of the atmosphere called the troposphere. 3. The movement of air tends to blow from high pressure to low pressure areas. 4. Changes in temperature lead to changes in air pressure, bringing different kinds of weather.
11 Made by Mrs. Villone Austintown Middle School Credits given to Holt, Rhinehart and Winston Science Textbook Company