weather hazards

• global atmospheric circulation


  the transfer of heat from the equator to the poles by the movement of air
• global atmospheric circulation 


  - divided into loops (cells)

  - has warm rising air that creates a low pressure belt

  - has cool sinking air tha creates a high pressure belt
• global atmospheric cells 


  - polar cells

  - ferrel cells

  - hadley cells
• Global atmospheric circulation model

  1. Sun warms the equator, causing air to rise (low pressure belt)

  2. As air rises, it cools and moves from the equator to 30* N + S, Cool air sinks (high pressure belt)

  3. At ground surface, the cool air ether moves back to equator (as trade winds) or to the poles (as waterlies), which curve because of the earths rotation

  4. At 60* N + S , warmer surface winds meet colder air from poles. warmer air rises (low pressure belt)

  5. Some air moves back to equator or moves towards the poles

  6. At poles, cool air sinks, high pressure air drawn back to equator
• tropical storms 


  - e.g. hurricanes, typhoons, cyclones

  • develop between 5 and 30*
  • sea temp. is 27*C or higher
  • wind shear is low
• reducing effects of tropical storms

  PREDICTING AND MONITORING

  • storms can be monitored using satellites, then computer models used to calculate a storm's predicted path
  • predicting gives people time to evacuate and plan
• PLANNING

  • building houses away from the coast
  • governents can plan evacuation routes
  • emergency services can prepare by practising rescuig people from flooded areas
• reducing effects of tropical storm

  PROTECTION

  • bildings can be designed to withstand tropical storms e.g. put on stilts
  • building flood defences e.g. levees and seawalls