Tropical storms .

What are tropical storms?
1. A deep area of low pressure in the tropics
2. How are tropical storms named?
  1. There are three names given to tropical storms depending on their location
    1. Hurricane - Atlantic/ East Pacific
    2. Cyclone - South east Asia
    3. Typhoon - Japan/Philippines
Distribution of tropical storms
1. Found close to the equator in a central band but not directly on the equator
Requirements for a storm to occur
1. Warm water i.e. The sea (27 degrees and above)
2. Summer/ autumn when the highest temperatures are
3. A latitude greater that 5 degrees north or south of the equator (not enough spin at the equator)
4. Tropical regions of severe air instability
  1. Low pressure where there is air rising and as it is moving the conditions are unstable
    1. (Stable conditions are where there is a heavy air mass which is sinking - cold air)
Tropical storms are measured on the Saffir-Simpson scale
Hurricane structure
1. Eye wall
  1. Strongest winds and heavy rain (this decreases in bands as you move further away from the eye wall)
2. Eye
  1. Region of calm weather in the middle of tropical storms
    1. Clear as sucking air from above which is sinking - this prevents clouds from forming
    2. Area of dense air and generally about 15-30 miles across
Who do tropical storms spin?
1. The coriolis effect bends and spins the warm rising air
  1. Hurricanes in the northern hemisphere bend to the right which causes the clouds to spin anti-clockwise
  2. Cyclones in the Southern Hemisphere swirl in a clockwise direction
What direction do tropical storms travel?
1. Travel from east to west due to the direction in which the earth spins
2. When they hit land they lose their energy source from the sea that powered them
  1. As they lose energy they change direction - in northern hemisphere track north and in Southern Hemisphere track south
Coastal areas are most at risk
1. When a tropical storm reaches land it has lost its power source - warm water
2. However further in land there can be flooding due to he heavy rain that can last for days
Formation
1. Air is heated above the surface of warm tropical oceans - the warm air rises rapidly under the low pressure conditions
  1. The rising air draws up more air and large volumes of water from the ocean causing strong winds
    1. The Coriolis effect causes the air to spin upwards around the central eye
      1. As air rises it cools and condenses to form large cumulonimbus clouds which generate torrential rainfall
        When air condenses into clouds latent heat is released (due to energy in bonds) which helps to power tropical storms
        The tropical storm travels across the ocean in the prevailing winds
        When the tropical storm meets land it is no longer fuelled by the source of moisture and heat from the ocean so it loses power and weakens
Typhoon Haiyan
1. 8 November 2013 at 4.40 am
2. Category 5 on Saffir-Simpson scale (155mph+ winds)
3. Death toll: 6,190
4. Overall cost of damage: US $12 billion
5. Struck Philippines (originated in northwest Pacific Ocean)
6. Effects
  1. 14.1 million people affected of which 4.8 million already day lived in poverty
  2. Total damage US$12 billion - rebuilding required
  3. Airport badly damaged - trade links and tourism
  4. Farm land destroyed and crops lost - recovery costs for agriculture and fishing US$724 million
7. Responses
  1. Immediate
    1. Evacuated 800,000 people
      1. People died when stadium flooded (meant to withstand winds)
    2. Essential equipment and medical supplies sent out by governemnt
      1. Within two weeks over one million food packs and 250,000 litres of water were distributed
    3. Help from other countries and organisations
      1. More than $1.5 billion was pledged in foreign aid
  2. Long-ten
    1. 'Build back better' scheme to upgrade buildings to be protected in the event of future disasters
    2. No build zone along he coast in Eastern Visayas
    3. New storm surge warning system
    4. Plans to rebuild the Tacloban-Paulo-Tanauan Road dike to protect against storm surges
Effects, responses and mitigation of tropical storms
1. Effects
  1. Strong winds
    1. Can demolish houses and destroy infrastructure and wipe out crops
    2. Tornadoes can also be caused by tropical storms
  2. Torrential rainfall and storm surges
    1. Storm surges - when the sea level rises rapidly and particularly high due to the storm
    2. Cause flooding and can trigger landslides
      1. Aid is affected as roads are flooded and water supplies can become contaminated with sea water, sewage and industrial waste
2. Responses
  1. Can generally be predicted
    1. Warning systems provide crucial information regarding strong winds, heavy rain and storm surges which are broadcast to the public
      1. Allows vital time to prepare and protect property
  2. Evacuation
    1. Evacuate to higher ground - away from the impact of storm surges
    2. Shelter provided by public buildings or nets provided by international aid are also necessary when homes are extensively damaged or destroyed
  3. Distributing supplies
    1. Distributing emergency food and water is essential for survivors in the aftermath of a tropical storm
    2. MEDCs are more likely to have the resources available o do this although during large-scale disasters international help is often necessary
    3. If there is large scale devastation it can take longer for aid to reach where it is needed especially in remote locations
      1. Aid may be hindered if roads have become blocked (due to debris/ fallen trees/ flooding)
3. Mitigation
  1. Repairing damage to existing buildings including homes
  2. Repairing infrastructure and businesses
  3. Ensuring the country is capable of managing a future hazard by investing in methods of protection and prediction of storms
    1. E.g. A new early warning system for storm surges or new sea defences

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	Created by Emily H over 7 years ago