| A | B |
|---|
| air mass | a large body of air that has moisture content and temperature similar to the water or land over which it formed |
| air pressure | air particles pressing down on a surface |
| atmosphere | air that surrounds our planet |
| barometer | instrument that measures air pressure |
| cirrus | thin wispy clouds at high altitudes |
| cumulonimbus | dark towering clouds that bring heavy rain |
| cumulus | puffy white clouds at middle altitudes |
| front | border formed where a cold air mass and a warm air mass meet |
| greenhouse effect | describes how heat from the sun is trapped in the atmosphere to warm Earth |
| humidity | amount of water vapor in the iar |
| hygrometer | instrument that measures humidity |
| stratosphere | layer of atmosphere just above most weather |
| stratus | thick gray clouds just above the Earth's surface |
| troposphere | layer of atmosphere that is closest to the Earth; most weather occurs here |
| precipitation | any form of water that falls from the atmosphere, such as rain, snow, sleet, or hail |
| mesophere | the coldest layer of the atmosphere |
| thermosphere | the hot, outermost layer of the atmosphere |
