| A | B |
|---|
| air mass | huge parcel of air that has the characteristics of the area over which it originated |
| atmosphere | blanket of gases about 900 km thick that surrounds |
| atmospheric pressure | force caused by the atmosphere down on earth |
| barometer | device that measures atmospheric pressure |
| cirrus clouds | high, thin, wispy clouds |
| climate | average weather of a area over a long period |
| cold front | front formed when a cold air mass moves into a warm air mass |
| condensation nuclei | dust or salt particles on which water in the atmosphere condenses |
| Coriolus effect | change in the path of air currents caused by the rotation of earth |
| cumulonimbus clouds | huge towering clouds that form when a cumulus cloud expands into a verticle rain cloud. Thunderheads |
| cumulus clouds | billowy clouds that resemble heaps of cotton |
| cyclones | winds cirrculating around a low pressure center |
| dew point | temperature at which water vapor in air condenses |
| greenhouse effect | warming of the atmosphere due to absoption by atmospheric carbon dioxide of long-wave energy radiated from earth |
| ionosphere | layer of ionized (charged) gases in the upper atmosphere |
| isobar | lines on a weather map connecting areas of equal atomospheric pressure |
| isotherm | lines on a weather map connecting areas of equal tempature |
| jet streams | upper level winds found in middle latitudes about 10km above earth surface |
| leeward | facing away from the wind |
| occluded front | front formed when a warm air mass is lifted upward as two cold air masses meet |
| ozone layer | the part of the stratosphere where absorption of ultraviolet rays occur |
| relative humidity | amount of water vapor in the air comapred to the maximum amount the air could hold at that temperature |
| stratosphere | layer of the atmosphere above the troposphere |
| stratus clouds | layered clouds that usually cover the whole sky |
| troposphere | layer of the atmosphere closest to the earth |
| warm front | front formed when a warm air mass moves into a cold air mass |
| windward | facing the wind |
