Extreme Weather

• Latitude


  The distance from the equator
• At the equator

  The Sun's rays are more concentrated and so it is much hotter than at the Poles
• At the Poles

  The Sun's rays are more spread out
• Atmospheric circulation


  The large-scale movement of air by which heat is distributed on the surface of the Earth
• Atmospheric circulation

  1. Air rises at the equator creating low pressure (rain clouds)

  2. Air sinks at 30° creating high pressure (this is the Hadley Cell)

  3. Surface winds are created when air moves from areas of high pressure to areas of low pressure
• Tropical storm

  • They spin anti-clockwise in the northern hemisphere
  • They are circular shape
  • The eye is the centre of the storm (clear, cloudless and calm)
  • Eye wall has the strongest winds and torrential rainfall
• Typhoon Haiyan (8th November 2013) was a Category 5 storm that hit the PHILIPPINES with wind speeds of 314 KPH and waves 15M high
• Protection measures include reinforcing buildings, flood defences, and creating 'no-build zones'
• Planning involves getting people and the emergency services ready to deal with the impacts
• The Somerset Levels flooding in December 2013-January 2014 was caused by several depressions (storms) moving over from the Atlantic, saturated soil, and the wettest January on record
• Management strategies to reduce risk of flooding in the Somerset Levels included raising and strengthening river banks, dredging rivers, raising road levels, building flood defences, and constructing a pumping station
• Monitoring

  Satellites, monitoring clouds
• Prediction


  Supercomputers give 5 day warnings (early warning)
• Extreme weather in the UK includes storm events, flooding, droughts, heatwaves, and extreme cold weather
• Extreme weather is not new but more weather records are being broken recently than ever
• Tropical storms are known by many names, including hurricanes (North America), cyclones (India) and typhoons (Japan and East Asia), and they all occur in a band that lies roughly 5-30° either side of the Equator
• How tropical storms are created

  1. Air is heated above the surface of warm tropical oceans (27°C)

  2. Warm air rises rapidly under low-pressure conditions

  3. Strong winds form a rising air draws up more air and moisture

  4. The rising air spins around the central eye of the storm due to the Coriolis effect

  5. The rising air cools and condenses creating large clouds and torrential rainfall

  6. Heat is given off as it cools, powering the tropical storm

  7. The tropical storm travels across the ocean until it reaches land
• Climate change will increase atmosphere and sea surface temperatures
• The distribution of tropical storms is not expected to change significantly
• The frequency of category 4 and 5 storms is expected to increase, while the overall number of storms will stay the same
• The intensity of tropical storms is expected to increase, with more category 4 and 5 storms
• Typhoon Haiyan Primary Effects:

  • 90% of Tacloban destroyed
  • 6190 people died
  • 4.1 million homeless
  • US $12 million in damages
  • Oil spill
  • 75% of farmers and fishermen lost income
• Typhoon Haiyan: Secondary Effects

  1. Infections and disease spread

  2. Schools destroyed –no education

  3. Looting

  4. Fishing industry damaged

  5. Flooding caused landslides

  6. Roads blocked and airport closed
• Typhoon Haiyan: Immediate responses


  1. 800,000 people evacuated

  2. 1,200 evacuation centres set up

  3. Medical supplies sent in

  4. Emergency aid sent in (1 million food packs and water)
• Typhoon Haiyan: Long-term responses

  1. Oxfam replaced fishing boats

  2. Storm surge warning built

  3. Cyclone shelters built

  4. US $1.5 billion pledge in aid

  5. Government planned to 'build back better'