lesson 6

• TYPHOONS


  • Strong wind
  • Heavy rain
  • Central low pressure area
• Ingredients in tropical cyclone formation

  • Deep ocean water
  • Warm sea temperature (26.5 C+)
  • Coriolis force
• Why do tropical cyclones form?

  Redistribution of heat through wind from the equatorial regions to portal regions
• Storm surges


  Localized unusual increase of sea water level beyond the predicted astronomical tide level primarily due to intense winds and lowered atmospheric pressure
• THUNDERSTORM


  • Cumulonimbus clouds
  • Thunder & lightning
  • Strong winds
  • Intense rainfall
• Tornado characteristics


  • Thunderstorm
  • Hail
• Flood types


  • Riverine
  • Estuarine & coastal
  • Urban flooding
  • Catastrophic
• Riverine flood


  • Increase in river water levels due to extreme and sustained rainfall
  • Large river - slow rising
  • Small river - fast rising
• Estuarine & coastal flood


  • Storm surges
  • Unusually high tides
• Urban flooding


  • Large areas of impermeable surfaces
  • Man-made causes
• Catastrophic flood


  • Groundfailure, liquefaction, Landslides that may be triggered by natural disasters
  • Breakage of dams
• Flash flood


  Rapid & short-lived due to intense rainfall or collapse of dam
• ENSO (El Nino Southern Oscillation)


  • Cyclic fluctuations of warm and cold sea surface temperatures and atmospheric pressure in the central and eastern equatorial pacific
  • Causes extreme regional-scale weather and climate pattern changes
  • Most powerful climatic force on earth
• ENSO phases


  • El Nino (warm phase)
  • La Nina (cold phase)
• El Nino


  • Lasts for 9 months to 2 years
  • Starts between December to February
  • Occurs every 2 years - 9 years
• La Nina


  • Lasts 1 to 3 years
  • Occur Alternatingly and usually recur every 3-5 years or 2-7 years