Air, Weather, and Climate

• Weather


  Shows the way the atmosphere behaves and can change from minute-to-minute, hour-to-hour, and day-to-day<|>Characterized by the temperature, wind, precipitation, clouds, and other weather elements<|>Short-term state of the atmosphere<|>Atmospheric conditions that influence weather are always fluctuating, which is why the weather is changing
• Thunderstorms


  Violent, short-lived weather disturbance that is almost always associated with lightning, thunder, dense clouds, heavy rain, hail, and strong gusty winds<|>Form when warm, moist air rises into cold air<|>The warm air becomes cooler, which causes moisture (water vapor) to form small water droplets through a process called condensation<|>The cooled air drops lower in the atmosphere, warms, and rises again (convection cell)
• Three Main Stages of Thunderstorm

  1. Cumulus Stage

  2. Mature Stage

  3. Dissipating Stage
• Types of Thunderstorms

  • Single-cell Thunderstorms
  • Multi-cell Thunderstorms
  • Squall Lines
  • Supercell Thunderstorms
• Tornadoes


  Violently rotating column of air that extends from a thunderstorm to the ground that tears up everything in its path<|>Come from supercell thunderstorms that have winds already in rotation<|>Usually accompanied or preceded by severe thunderstorms and high winds (hail is also common)<|>Once a tornado hits the ground, it may live for as little as a few seconds or as long as three hours
• Tropical Cyclone


  Large, rotating storms that form over warm ocean waters<|>Known by different names in different parts of the world (hurricanes, typhoons, and cyclones)<|>Fueled by the warm water and produce strong winds, heavy rain, and storm surge
• Winter Storms


  Associated with cold air masses and can produce a variety of precipitation, including snow, sleet, and freezing rain<|>Can also cause blizzard conditions, which include strong winds and blowing snow
• Blizzards


  Severe winter storms characterized by strong winds, blowing snow, and very cold temperatures
• Dust Storms


  Caused by strong winds that pick up large amounts of dust and sand from the ground<|>Reduce visibility and can have negative impacts on air quality
• Sandstorms


  Caused by strong winds that pick up large amounts of sand<|>Most common in deserts and other arid regions
• Ice Storms


  Winter storms that produce freezing rain (rain that freezes on contact with surfaces)
• Climate


  Refers to the weather patterns in terms of the condition and their fluctuation over a certain time span and a certain area
• Climate


  • Varies from place to place and varies in time from season to season, year to year, decade to decade, or on much longer time scales
  • Long term pattern of weather
  • Variations and change are caused by external forcings that may be partly predictable, particularly on the larger, continental and global, spatial scales
  • Determined by the atmospheric circulation and by its interactions with the largescale ocean currents and the land with its features such as albedo, vegetation, and soil moisture
  • Climate of the Earth as a whole depends on factors that influence the radiative balance, such as atmospheric composition, solar radiation, or volcanic eruptions
  • Areas closer to bodies of water (oceans, lakes, etc.) tend to have more moderate climates due to the water's ability to absorb and release heat slowly, creating a buffering effect on temperature extremes
  • Influenced by latitude, with areas closer to the equator receiving more direct sunlight and generally being warmer
  • Topography (mountains, etc.) can affect wind patters and precipitation as wind can be blocked and rain shadows can be created on their leeward sides
  • The type of vegetation present in a region can also influence climate
• Winds


  Movement of air relative to the Earth's surface, caused by horizontal and vertical differences in atmospheric pressure
• Wind Speed


  Speed of the weather-related air movement from one place to the next in an outside environment
• Wind Direction


  Reported by the direction from which wind originates
• Global Wind Patterns

  • Polar Easterlies (from 60-90 degrees latitude)
  • Prevailing Westerlies (from 30-60 degrees latitude)
  • Tropical Easterlies (from 0-30 degrees latitude, trade winds)
• Clouds


  Visible collections of water droplets or ice crystals suspended in the atmosphere
• Clouds form


  When rising air cools and condenses
• Humidity


  Water vapor present in the atmosphere
• Precipitation


  Any form of water that falls to the Earth's surface including rain, snow, sleet, and hail
• Precipitation occurs

  When water vapor in the atmosphere condenses and grows too heavy to remain suspended
• Air Masses


  Large body of air with similar temperatures and moisture characteristics
• Types of Air Masses

  • Continental Polar (cold and dry)
  • Continental Tropical (hot and dry)
  • Maritime Polar (cool and moist)
  • Maritime Tropical (warm and moist)
• High-Level Clouds

  More than 20,000 feet above the ground
• Cirrus


  Wispy, feathery clouds that are made of ice crystals
• Cirrocumulus


  Small white puffs or patches that resemble fish scales, made of ice crystals
• Cirrostratus


  Form a thin sheet that covers the entire sky, made of ice crystals
• Mid-Level Clouds

  6,500 to 20,00 feet above the ground
• Altocumulus


  Appear as gray or white patches/sheets composed of tiny water droplets
• Altostratus


  Form a gray or blue sheet that covers most or all of the sky
• Nimbostratus


  Dark, gray sheets that often produce continuous light rain or snow
• Low-Level Clouds

  Below 6,500 feet above the ground
• Stratus


  Form a gray featureless sheet that covers the entire sky
• Stratocumulus


  Clouds appear as gray or white patches/rolls that often resemble a lumpy patchwork quilt
• Cumulus


  Puffy, white clouds that resemble cotton balls
• Cumulonimbus


  Large, towering clouds that produce heavy rain, thunderstorms, and sometimes hail
• Thermometer


  Measures air temperature
• Barometer


  Measures atmospheric pressure
• Hygrometer


  Measures humidity, the amount of water vapor in the air