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May 9, 2016
Chapter 12 - Weather Vocabulary
Atmosphere – layer of gases surrounding Earth that protects living things from harmful doses
of ultraviolet radiation and X-ray radiation and absorbs and distributes warmth.
Aerosol – solids such as dust, salt, and pollen and liquid droplets such as acids that are
suspended in the atmosphere.
Air Mass – large body of air that develops over a particular region of Earth’s surface.
Dew Point – temperature at which air is saturated and condensation can occur.
Front – boundary that develops where air masses of different temperatures collide. Can be
cold, warm, stationary, or occluded
Humidity – amount of water vapor in the atmosphere.
Precipitation – occurs when drops of water or crystals of ice become too large to be
suspended in a cloud and fall in the form of rain, freezing rain, sleet, snow, or hail.
Relative Humidity – measure of the amount of water vapor in the air compared with the
amount that could be held at a specific temperature.
Troposphere – layer of the atmosphere that is the closest to the Earth’s surface and contains
nearly all of its clouds and weather
Water Cycle – never ending cycle in which water circulates between Earth’s surface and the
atmosphere through the processes of evaporation, transpiration, precipitation, and
condensation.
Weather – current condition of the atmosphere including cloud cover, temperature, wind
speed and direction, humidity, and air pressure.