| A | B |
|---|
| Changes in weather are caused by | the movement and interaction of air masses |
| air mass | large body of air where TEMPERATURE and MOISTURE are CONSTANT |
| air masses are characterized (described) by | moisture content and temperature |
| source region | AREA over which the air mass forms |
| air masses on a map are represented by a | TWO letter symbol |
| martime | forms over water; WET |
| continental | forms over land(continent): DRY |
| polar | forms over the POLAR regions: COLD |
| tropical | forms over the Tropics: WARM |
| mP | cool wet front |
| cP | dry cool front |
| cT | dry warm front |
| mT | wet warm front |
| air masses from different areas do not mix because | theyahve different densities |
| warm air is _____dense than cold air | less |
| front | boundary between air masses of different densities and temperatures MEET |
| 4 kinds of fronts | cold, warm, occluded, stationary |
| cold front | cold air moves UNDER less dense warm air, and pushes the warm air UP |
| cold front bring | heavy rain, thunderstorms or snow |
| warm front | warm air moves over cold, denser air and gradually replaces the cold air |
| warm fronts | bring drizzly rain |
| occluded front | a warm air mass is caught betwen TWO colder air masses |
| occluded front bring | large amounts of rain or snow |
| stationary front | cold air mass meets a warm air mass but neither is pushed out of the way |
| stationary front bring | MANY days of cloudy, wet weather |
| Major masses that influence weathe in the US | maritime, continental, polar ad tropical |
| Fronts cause weather changes | by moving warm air UP |
| cyclone | areas that have LOWER pressure than the areas around it and has WINDS THAT SPIRAL toward the center |
| ANTIcyclone | rotation of air around a HIGH pressure center in the direction OPPOSITE to the Earth's rotation |
| air in a cyclone | RISES and brings stormy weather |
| air in an anticuclone | SINKS and brings dry clear weather |
