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WEATHER PowerPoint Presentation

WEATHER

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WEATHER

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  1. WEATHER

  2. AIR MASS huge mass of air with similartemperature and humidity characteristics huge section of the troposphere in which the temperature and humidity are fairly uniform at any given level name an air mass from itstemperature and humidity

  3. SOURCE REGION location over which an air mass sitsand acquires itstemperature and humiditycharacteristics

  4. two broad types of surfaces on earth: waterland the humidity characteristic of an air mass comes from the type of surface of the source region water = moist land = dry maritime continental m c

  5. temperature comes from latitude of the source region equatorial E hot tropical T warm polar P cool or cold arctic A very coldantarctic AA

  6. humidity temperature m, c E, T, P, A mE cE mT cT mP cP mA cA 6 8 NAME AN AIR MASS=one of these six choices

  7. AIR MASS SOURCE REGIONSNorth America cP-cA mP mP cP mT cT mT mT

  8. the characteristics of an air mass dominate the weather of locations within the air mass cE--hot and dry cT--warm and dry mT--warm and moist cP--cool or cold and dry mP--cool or cold and moist cA--very cold and dry air mass weather--dominated by an air mass

  9. air masses move away from their source regions FRONT boundary between two different air masses

  10. the earth’s rotation makes a frontal boundary surface a gentle slope warm air is less dense than cold, so the warm air rises over the colder, denser air

  11. 4 TYPES OF FRONTS warm front--warm air moves in to replace cold cold front--cold air moves in to replace warm stationary front--boundary between two different air masses which is not moving appreciably occluded front--more complex, to be defined later

  12.    cold air   cold front cold air       warm front warm air warm air cold air stationary front warm air occluded front weather map symbols N

  13. Cross-Section of a Warm Front

  14. cumulonimbus cold air warm air Cross-Section of a Cold Front

  15. Cross-Section of a Stationary Front

  16. polar front begins as a stationary front

  17. the polar northeasterlies begin to push the air mass southward, and the prevailing southwesterlies begin to push an air mass northward

  18. stationary front polar front    L cold   warm L   cold  warm

  19. L  L  cold    cold warm  warm repeated illustration for comparison

  20. Middle Latitude Cyclone

  21. polar front    L cold    warm L  L  cold    cold warm  warm Middle Latitude Cyclone

  22. L   cold  warm OCCLUDED FRONT map view cross-section cold air cool air surface cold-front type occlusion

  23. L cumulonimbus   cold  cold air warm MAP VIEW Cross-Section of Middle Latitude Cyclone with center of the low to the north

  24. cold air cumulonimbus The Process of OCCLUSION