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mireille-clarke
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Atmospheric Pressure

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  1. aka air pressure • Caused by • Units • 14.7 psi • Why aren’t we crushed? • Air pushing out • Used to it • Decreases with altitude/elevation Atmospheric Pressure

  2. Air moves from high pressure to low pressure • Wind • Larger pressure differences = stronger winds • Named for direction • Wind chill • What temp. feels like to us • Humans only • Cause • Related to dangerousness of wind and cold temp. • Frostbite • Hypothermia Wind – What is it?

  3. Land warms/cools faster • Hot air rises • Lower pressure over land • Breeze from ocean (high to low pressure) • Cools the land • Opposite at night Local Wind

  4. What? • Warm winter winds • Dramatic temperature changes • Where? • Mountains • Moist air • How? • Clouds formed • Heat released • Warmer air than without clouds • Red belt Chinook Winds

  5. Similar temp. and humidity • Air that has stayed in a place • Quickly change because they move • Named for where they form • Maritime vs. Continental • Tropical vs. Polar Changing Weather -Air Masses

  6. What is wind chill and why is it important to humans? • What creates wind? • How are Chinook winds created? • How can the wind be a benefit to you when you live on the ocean shoreline? • A maritime tropical air mass exists over Colorado today, what would the air be like? Daily Review #3

  7. Air masses don’t mix • Front = boundary between them • What happens? • Warm, less dense air moves up • Cold, more dense air sinks • Types • Cold • Warm • Stationary • Occluded • Type of cloud can tell you what type of front Fronts

  8. Form in severe thunderstorms • Wind at different altitudes is different speeds • Creates swirling winds • Eventually become vertical • Swirling cloud reaches ground = tornado • Not on ground for long • Extremely low pressure • Winds 100-400 mph • Not well understood Tornadoes

  9. Describe how warm, cold, stationary and occluded fronts are different. • Explain how a tornado is formed. • Where would you probably not find tornadoes and why? Daily Review #4

  10. Unequal heating at different latitudes • Equator (lower latitudes) • Warmer air • Rises, lower pressure • Moves towards poles • Sinks when cools, higher pressure • Convection cells • Patterns of moving air and high/low pressure • Create areas of high and low winds • Jet stream • High speed wind • Upper troposphere, lower stratosphere • No consistent path • Effect weather patterns Global Wind

  11. Wind moves in a straight line • Earth’s rotation • Causes appearance of curving • Northern Hemisphere = clockwise (right) • Southern Hemisphere = counter-clockwise (left) Coriolis Effect

  12. Large weather systems • Impacted by Coriolis effect • Cyclone • Low pressure • Pulls air in and upward • Produces storms • Anti-cyclone • High pressure • Air moves out and downward • Clear skies Cyclones

  13. Winds at least 74 mph • Form over tropics • Warm, moist air forms clouds • Rotating • More water evaporates • Creates low pressure “eye” • Lacks wind • Gets larger with more evaporation • Loses energy once it hits land • No more “fuel” • Cyclones, typhoons, hurricanes Hurricanes