Global Atmospheric Circulation and Tropical storms Flashcards
The Challenges of Natural Hazards - Weather Hazards
what is Global atmospheric circulation?
the transfer of heat from the equator to the poles by the movement of air
how and why does air move?
due to differences in air pressure - winds blow from high pressure areas to low pressure areas
the system is divided into loops (called cells), what are they?
each cell has warm rising air that creates a low pressure belt and cool sinking air that creates a high pressure belt
how does Global atmospheric circulation affects weather around the world?
- the Earth’s surface receives a lot of solar radiation, so its hot
- the air reaches 30 degrees north and south of the equator, it has released most moisture as rain
- the UK lies close to the low pressure zone at 60 degrees north
what are the features of a Tropical storm?
- the centre of the storm is called the Eye
- the eye is surrounded by the eyewall
- towards the edges of the storm there is rising air
- near the top is descending air
what are the structure of a Tropical storm?
- there’s very low pressure, light winds, no clouds or rain and a high temperature in the eye
- there is spiralling rising air and very strong winds at the eyewall
- the wind speed falls, temperature increases and rain becomes less intense towards the edges of the storm
what is Typhoon Haiyan?
- one of the most powerful storms ever recorded
- a storm surge with waves of up to 2.3m, combined with a high tide meaning it was hit by waves of up to 5m
- this happened in 2013
what were the primary effects?
- over 6300 people were killed
- the cost of damage was estimated at around US $13 billion
- 1.9 million people were made homeless
what were the secondary effects?
- 5.6 million workers lost their jobs after businesses and agricultural land were destroyed
- flooding triggered several landslides
- the lack of clean water caused outbreaks of diseases (e.g dysentery)
what are immediate responses?
- fishermen were warned not to go to sea
- the Philippines declared a state of emergency, leading to many charities offering aid (food, shelter, water)
- Plan International constructed pit latrines for 100,000 people to prevent the spread of disease
what are long-term responses?
- charities built new storm-resistant houses for those who lost their homes
- the UN appealed for over $300 million to help fund rebuilding and relief
- the Philippines’ tourism board encouraged people to visit the country after the storm