Tropical storms

• Isolation - the concentration of sun's rays on the earth
• Cells:

  1. Polar
  2. Ferrel
  3. Hadley
  4. Ferrel
  5. Polar
• Global atmospheric circulation model:

  1. At the equator air rises, leading to low pressure and rainfall.
  2. When the air reaches the edge of the atmosphere it cannot go further, so it travels to the north or south.
  3. This causes the air to become colder and denser, as a result it will sink.
  4. This creates high pressure and dry conditions, around 30 degrees north and south of the equator.

  
• What tropical storms need to form:

  • Warm water, >27 degrees
  • In summer and autumn, when sea temperatures are the highest
  • In shallow water, 60-60 metres
  • Between 5-15 degrees north and south of the Equator
• Formation of tropical storms:

  1. Air is heated which rises rapidly, which draws in more air and large volume of moisture from the ocean. This causes strong winds.
  2. The rising air starts to cool and condense forming clouds. This releases latent heat, which powers the tropical storm.
  3. The winds will start to spiral into the storms eye, due to the coriolis effect. This causes the colder, dry air to sink into the eye, causing the calm conditions in the eye.
  4. The storm continues to expand it reaches land, which causes friction, which slows it down, and it loses its power source.
• What a storm looks like:

  • Spins clockwise in the southern hemisphere, while it sins anticlockwise in the northern hemisphere
  • Has a eye in the middle ~ which has calm weather, whereas the eyewall has heavy wind and rain
  • Width: 240 - 320 km
  • Height: >13 km
  • Speed: up to 252 km/h
• Tropical storms are measures in Saffir-Simpson Scale

  
• Impact of climate change on tropical storms:

  • There will be no change in the frequency
  • They will become more intense (Higher rainfall and stronger winds) due to sea temperatures rising
  • May start to spread further away (north and south) from equator, due to more oceans will reach >27 degrees
• Reducing effects of tropical storms:

  • Monitoring
  • ~ satellites; can monitor cloud patterns and rainfall
  • ~ aircraft's; special aircraft's fly into storms to collect data

  
  

  • Prediction
  • ~ warnings are issued by hurricane centre in Miami
  • ~ these can be: Hurricane Watch (conditions are possible) and Hurricane Warning (conditions are expected)

  
  

  • Protection
  • ~ install hurricane straps between roof and walls
  • ~ reinforce windows and doors
  • ~ build seawalls to protect from storm surges
  • ~ drains
  • ~ build coastal homes on stilts

  
  

  • Planning
  • ~ education
  • ~ disaster supply kits
  • ~ early warning systems