1. Weather & Climate Chapter 1 Section 3

2. OBJECTIVE: Investigate and describe characteristics of the atmospheric layers.

3. 1.The 4 main layers of the atmosphere are classified according to changes in the temperature. These layers are the… TROPOSPHERE STRATOSPHERE MESOSPHERE THERMOSPHERE

4. 2.Troposphere: Lowest layer of Earth’s atmosphere. We live in this layer and Earth’s weather occurs in this layer 0-12 KM - -60* C at the top of the troposphere. 3.Stratosphere: Extends from the top of the troposphere to about 50 KM Above Earth’s Surface (12KM – 50KM). The Ozone layer is in the Stratosphere and absorbs U.V. radiation. 4.Mesosphere: Middle Layer – The coldest layer (-90*C) 50-80KM above Earth’s surface -Most meteoroids burn up in the Mesosphere, producing meteor trails.

5. 5.Thermosphere: Outermost layer of the atmosphere. It extends from 80KM - ?? Even though the air in the thermosphere is very thin, it’s very hot (up to 1800* C). 6.Ionosphere: Is the first part of the Thermosphere. It extends from 80KM-550KM above Earth’s Surface. Sun’s energy causes gas molecules to become ions. Radio waves bounce off ions. Auroras occur in the ionosphere. 7.Exosphere: Is the outer layer of the Thermosphere. It extends From 550KM- Thousands of KM above Earth’s surface. Long distance Phone calls and television signals come from satellites in the Exosphere.