| A | B |
|---|
| any form of water that falls out of the clouds | precipitation |
| a cloud at ground level | fog |
| a large body of air that forms over a source region | air mass |
| the weather maker | sun |
| the troposphere's topmost boundary | tropopause |
| the temperature at which cooling air becomes saturated | dew point |
| the boundary between two air masses | front |
| the process in which water vapor leaves the air and changes back into liquid water | condensation |
| an imaginary line circling the earth midway between the poles | equator |
| another name for the cumulonimbus cloud | thunderhead |
| three ingredients for clouds | water, rising air, dust |
| three things that cause air to rise upward, often forming clouds | solar heating, mountains, fronts |
| the three kinds of fog | steam, radiation, sea |
| three major wind systems | trade, prevailing westerlies, polar easterlies |
| three kinds of icy precipitation | sleet, freezing rain, hail |
| scientist who studies weather | meteorologist |
| the imaginary line running through the earth from the North Pole to the South Pole | axis |
| most of our warmth comes from here | ground |
| seasons are caused by this | tilt of the earth's axis |
| wind can be produced by this | temperature differences |
| warm air is _____ than cool air | heavier |
| how fast the earth's surface spins | 1,000 |
| the amount of water vapor the air can hold at a given temperature | relative humidity |
| lowest possible temperature where air can hold all of its water | dew point |
| water vapor leaves the air and changes into liquid water | condensation |
| air is saturated at what percent | 100 |
| water vapor that condenses to form liquid water on the ground | dew |
| water vapor that condenses and forms frozen water on the ground | frost |
