Weather Hazards

• Global atmospheric circulation is all about the way that heat and gases circulate in the atmosphere
• What happens when there is low pressure?


  storms, rains etc because the air is rising away from the Earth
• What happens when there is high pressure?


  clear skies and calm winds because air is sinking towards the Earth and pushing down on it
• There are three main types of global atmospheric circulation: Hadley cells, Ferrel cells & Polar cells.
• Ferrel Cells are located between the polar front and subtropical high pressure belt. These cells move cold dense air from the poles towards the equator where it warms up and rises again at the equator.
• Hadley Cells are located near the Tropic of Cancer and Tropic of Capricorn. Warm moist air moves from the equator towards the poles where it cools and falls back towards the equator as dry air.
• Polar Cells are located above latitude 60° and they have very cold temperatures. Due to these extremely cold conditions, the air cannot rise or fall easily. Instead, it just blows around in circles due to the Coriolis effect. These cells do not contribute significantly to the overall circulation pattern.
• The Coriolis effect causes wind to deflect to the right in the northern hemisphere and left in the southern hemisphere due to the rotation of the earth.
• Tropical storms are also known as typhoons around the pacific ocean, and cyclones around the Indian ocean.
• A hurricane/ typhoon/ cyclone is a large low pressure system characterised by high winds and heavy rain
• The distribution of tropical storms seem to mainly sit near the equator. There are many typhoons in countries such as Philiphines and also a lot in central America
• Conditions required for a tropical cyclone to form

  • Large, still, warm ocean area with temp above 27 degrees celcius
  • Low latitude winds
• The centre of a hurricane is called "the eye", it is the calmest part
• Vortex = spinning high winds and heavy rainstorms
• Typhoon Haiyan was in Philliphines, 2013

  • Saffir-Simpson category: 5
  • Maximum wind speed was 275km/h
• Primary effects of Typhoon Haiyan:

  • Over 5000 deaths
  • Flooding
  • Tacloban terminal airport destroyed
• Secondary effects of Typhoon Haiyan

  • Many left homeless
  • Flooding caused landslides
  • Shortages of food, water and shelter
  • Looting and violence broke out in Tacloban
• Immediate responses to Typhoon Haiyan

  • Over 1200 evacuation centres to help homeless
  • International GOV + aid agencies responded
  • Provided shelter kits
  • US aircrafter George Washington and helicopters assisted with search and rescue
• Long-term responses to Typhoon Haiyan

  • UN countries donated financial aid + supplies
  • Rebuilding of roads
  • More cyclone shelters built
  • 'Cash for work' programmes (ppl paid to help clear debris + rebuild)
• Weather is the day-to-day conditions of the atmosphere
• Somerset Floods


  The Somerset Floods were a series of severe floods that affected the county of Somerset in southwest England, particularly in January 2014. Heavy rainfall and a combination of high tides and storm surges caused widespread flooding, affecting over 1,000 properties and causing significant damage and disruption to businesses and communities.
• Low-lying means the land is flat and not much higher than the levels of the sea. This means it can flood easily.
• What are the social impacts of the Somerset floods?

  • Mental health impacted
  • People has to search for accommodation
  • Affect of school and work
• What are the economic impacts of Somerset flood?

  • House repairs costed £60 million
• What were the environmental impacts of Somerset Floods?

  • Animals dying/ drowning
• An overview of types of weather hazard experienced in the UK.

  • Thunderstorms
  • Heatwaves
  • Floods