1. Journal #21 What are the 2 types of barometers? What is standard atmospheric pressure? Which type of barometer is most commonly used? An instrument used to measure altitude is called a ____?

3. Layers of the Atmosphere Earth’s atmosphere has a distinctive pattern of temperature changes with altitude. There are four main layers of the atmosphere. The troposphere The stratosphere The mesosphere The thermosphere

4. The Troposphere The Troposphere is the atmospheric layer that is closes to the Earth’s surface. This is where nearly all weather occurs. Almost all the water vapor and carbon dioxide in the atmosphere is found in this layer. Temperature within this layer is heated from below by heat that radiates from the Earth’s surface.

5. The Stratosphere The stratosphere extends from the troposphere to an altitude of nearly 50 km. Almost all of the ozone in the atmosphere is concentrated in this layer. Lower stratosphere -60 degrees Celsius Upper stratosphere The temperature increase as altitude increases because it is heated from above by solar radiation.

6. The Mesosphere Located above the stratosphere about 80 km is the mesosphere. In this layer, temperatures decrease as altitude increases. This layer is the coldest layer of the atmosphere

7. The Thermosphere The uppermost layer of the atmosphere is the thermosphere. In this layer, temperature increases steadily as altitude increase because nitrogen and oxygen absorb solar radiation. The lower region of the thermosphere is called the ionosphere because solar radiation causes the atoms of gas to lose electrons and produce ions Interactions between solar radiation and the ionosphere cause auroras (pg 553)

8. Air Pollution Any substance that is in the atmosphere and that is harmful to people, animals, plants or property is called an air pollutant. Today, the main source of air pollution is the burning of fossil fuels, such as coal and petroleum. The burning of these fuels, release harmful chemical substances into the air.

9. Temperature Inversions Certain weather conditions make pollution worse. One of these condition is temperature inversion- the layering of warm air on top of cool air. Warm air can trap cool polluted air beneath it. When air cannot circulate up and away from an area, automobile exhaust can produce smog. Air pollution can only be controlled by preventing the release of pollutants into the atmosphere.

10. Your Assignment Draw a diagram of the 4 layers of the atmosphere (also include the ionosphere) Use color and labels. Use pictures that describe the layer Example: the troposphere has weather = draw clouds, rain and snow Example: the mesosphere is cold= draw something cold or a thermometer showing it is very cold Use page 552 as a reference.