Weather & Atmosphere

  • Weather & Atmosphere
Weather and Atmosphere Unit
weather
 
 Important Vocabulary
  • Weather: is used to describe what's happening outside at a specific time and place, and it can change from day to day or even within a day.
  • Meteorologist: scientists who study weather.  When measuring and describing weather conditions, meteorologists may record data such as wind speed, air pressure, and precipitation.
  • Precipitation: is any form of water that falls to earth, including rain, snow, sleet and hail.  The amount of precipitation and other weather data can vary from hour to hour, day to day, and season to season.  
  • Atmospheric Scientist: scientist who study the atmosphere, from the surface of the earth to several hundred kilometers above.  They may collect and analyze data about current and past conditions. 
  • Climate: describes the average weather in a place over a fairly long period of time (usually at least 30 years).
  • Climatologist: scientists who study the earth's climates.  They use such factors as temperature and precipitation to describe different types of climate.
  • Climate Type:
    • Highland: very high mountains, such as the Rocky Mountains in the western United States. Cold to cool year-round, with temperatures between -2 and 50 degrees.  Amount of precipitation varies, usually falling as snow in winter.
    • Mild: Summers are warm or hot, with temperatures over 50 degrees. Winters are cool or cold, wither temperatures below 64 degrees but above -3 degrees. Moist climate, often with more precipitation in either the winter or summer.
    • Polar: Extremely cold and long winters, with only 2-4 months having temperatures above freezing.  Cool summers with temperatures less than 50 degrees. Dry year-round, with very little precipitation (usually falls as snow)
    • Severe: warm summers, with temperatures over 50 degrees.  Very cold winters, with at least one month averaging less than 27 degrees.  Amount of precipitation varies.
    • Dry: Hot days and cool nights year-round.  Maximum temperatures usually over 88 degrees.  Dry year-round, with very little precipitation. 
    • Tropical: Hot year-round with temperatures averaging over 64 degrees.  Wet, with a total of more than 150 centimeters of rain in a year.
  • Hydrologist: Scientists who study the distribution and movement of the earth's water.  
  • Ocean Current: regular movements of large amounts of ocean water.  Some of these currents move warm water from place to place, while others move cool water.
  • Gulf Stream: The Gulf Stream is a strong, fast moving, warm ocean current that originates in the Gulf of Mexico and flows into the Atlantic Ocean.This extensive western boundary current plays an important role in the poleward transfer of heat and salt and serves to warm the European subcontinent.
  • Solvent: a liquid that has a solid dissolved in it. 
  • Salinity: driving factor in ocean currents.  It is the amount of salt dissolved in water.
  • Water Cycle: When water moves all around the earth.  Water evaporates from the oceans into water vapor.  Water vapor in the atmosphere condenses to form the tiny water droplets in clouds.  Clouds release the water, and it falls back to earth as rain, snow, or hail.  This movement is the water cycle.  Heat from the sun drives the water cycle.  This cycle is critical for the climates around the world, without it climates would be very different.
  • Water: Water can be found on the earth as a liquid, solid, and a gas. 
    • Solid: Sometimes water is frozen solid and falls to the earth as snow, ice, or hail.
    • Liquid: water is in the form of a liquid when it is raining or flows in a river or in the ocean.
    • Gas: When water is in the form of gas, you cannot usually see it, but you can sometimes feel it.  When water is in the form of a gas it is fog or water vapor.
  • Evaporation: Liquid becomes water vapor.  If you leave a glass of water out the water will "disappear", but really it just changes states.
  • Condensation: water vapor turns back into a liquid.  This often occurs in the sky, when water vapor condenses into tiny water droplets and forms clouds.
  • Melting: Water goes from a solid to a liquid.
  • Freezing: Water goes from a liquid to a solid.
  • Water Vapor: When water is a gas.
  • Clouds: large collections of water, usually in the form of tiny droplets of liquid and solid water.  When these droplets become too heavy for air currents to hold them up, they fall down to earth as rain, snow or hail.
  • Humidity: is the word meteorologists use to describe the amount of water vapor in the air.
  • Atmosphere: air that surrounds the earth. The atmosphere is the layer of gases that surroundings the earth.  The main gases are nitrogen (78%) and oxygen (21%), with the remaining 1% made up of other gases including carbon dioxide, water vapor, and argon.  There are 5 layers.
    • Troposphere: 0 - 12km. most weather occurs here.  Cruising altitude of most commercial aircraft.
    • Strasophere: 12 - 50 km. Ozone layer absorbs some of the sun's harmful ultraviolet radiation before it strikes the earth's surface.
    • Mesosphere: 50 - 80 km. Meteors usually burn up.
    • Thermosphere: 80- 120 km. The space shuttle orbits the earth.
    • Exosphere: 120 km +. The earth's atmosphere merges into space.

 

 

  • Weather Forecast: the prediction of what the weather will be like in the next few hours, days, or the next several days.
    • Pressure: There are high and low pressure systems.  High pressure systems bring clear skies and low pressure systems bring cloudy skies with possible precipitation.
  • Front: a boundary where a mass of air meets another air mass of a different temperature.
  • Cold Fronts: which form when cold air moves in and replaces warm air.The cold air pushes the warm air up, forming high columns of clouds.  Cold fronts usually have cooler temperatures.
  • Warm Fronts: occurs when warm air moves in and replaces cooler air.  Warm front bring warmer temperatures.  They also create cloudy conditions that usually last longer than the cloudy conditions produced by cold fronts.
  • Wind: Horizontal movement of air.
  • Anemometer: measure wind speed.
  • Wind Vane: measure wind direction.
 
 
Additional Links to Help with Reviewing and Studying!
WEATHER & ATMOSPHERE:
Follow this link to find additional resources about weather and atmosphere including links to local weather information, wind data from around the globe, and an interactive site that enables you to discover more about earth's atmosphere.

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