| A | B |
|---|
| atmosphere | five different layers determined by changes in temp. with increasing altitude |
| troposphere | weather happens here; layer closest to Earth and warmer than top of the layer |
| stratosphere | where jet planes fly; ozone layer absorbs harmful ultraviolet rays |
| mesosphere | middle layer; coldest parts of atmosphere |
| thermosphere | few air molecules; hottest layer in atmosphere |
| exosphere | upper layer where astronauts "feel" atmosphere begin; atoms/molecules escape to space |
| convection currents | gases or liquids that rise/sink in circular path causing wind; air moves from high air pressure to place of low air pressure |
| air masses | large bodies of air with similar properties |
| front | boundary between two air masses; can span 20+ miles |
| cold front | cold air replaces warm air at surface; associated with shorter periods of precipitation |
| warm front | warm air replaces cold air at surface; long periods of precipitation |
| stationary front | power of warm/cold front are the same & the front stops moving; behaves like a warm front |
| occluded fronts | two cold fronts overtake a warm front; results in clouds, rain, and snow |
| meteorologist | scientists who study weather and atmosphere |
| barometer | shows air pressure |
| anemometer | measures wind speed |
| hygrometer | measures moisture in the air |
| rain gauge | a tool that measures how much rain has fallen |
| radar | a computer model which measures winds and precipitation inside a storm |
| thermometer | an instrument for measuring temperature |
| wind vane | an instrument for measuring wind direction |
| climate | the average of weather conditions over a long time |
| weather | the condition of the atmosphere at a certain time and place |
