Key Terms

• weather



  the day to day conditions
• climate 


  the weather conditions over a long period of time
• troposphere

  the lowest region of the atmosphere extending from the Earths surface, about 6-10 km
• stratosphere

  the layer of the Earth's atmosphere above the troposphere
• air pressure



  the weight of the air pressing down on the Earth's surface due to the weight of the atmosphere
• meteorology

  the study of weather
• air masses


  a huge block of air with the same temperature and moisture content. they take on the characteristics of the surface below it
• precipitation

  any liquid that forms in the atmosphere and falls back to Earth
• prevailing wind


  a wind from the direction which is most common