| A | B |
|---|
| troposphere | the lowest layer of the atmosphere |
| stratosphere | the second layer of the atmosphere and it contains the ozone layer |
| mesosphere | the third layer of the atmosphere and it protects Earth from being hit by most meteoroids |
| thermosphere | the outermost layer of the atmosphere |
| the layers of the atmosphere are divided in this way | according to changes in temperature |
| thermosphere is divided into two sections | ionosphere and exosphere |
| where we live | troposphere |
| conditions change often in this layer | troposphere |
| troposphere | the layer in which weather occurs |
| shallowest layer-about 12 km | troposphere |
| as the altitude increases in the troposphere | the temperature decreases |
| top of troposphere | temperature stops decreasing-stays at -60 degrees Celsius-cirrus clouds form here |
| stratosphere | layer directly above the troposphere |
| stratosphere | about 38km thick |
| lower stratosphere is cold | about -60 degrees Celsius |
| upper stratosphere is warmer than the lower stratosphere | the upper stratosphere contains the ozone layer--IT ABSORBS ENERGY from the sun and WARMS the air |
| statosphere | this layer converts energy from the sun into heat and warms the air |
| mesosphere | directly above the stratosphere |
| mesosphere | known as the middle layer of the atmosphere |
| mesosphere | about 30km thick and protects Earth's surface from being hit by most meteoroids |
| air at the top of the atmosphere | very thin--not dense |
| thermosphere | located at the top of the atmosphere |
| thermosphere | outermost layer of the atmosphere |
| thermosphere | begins at about 80 km from the Earth's surface and has NO DEFINITE OUTER LIMIT |
| thermosphere | gradually blends with outer space |
| thermosphere | VERY HOT- up to 1800 degrees Celsius because sunlight strikes this layer first |
| we would not feel warm at this level | the thermosphere-because the air is soooo THIN |
| thermosphere is divided into two layers | ionosphere and exosphere |
| ionosphere | has radio waves that reflect back to Earth |
| aurora borealis | Northern light that occur in the ionosphere |
| exosphere | contains communication satellites |
