Weather Hazards Flashcards
describe the global atmospheric circulation model
- warm air rises from the Equator, creating a belt of low pressure - as the air rises, it cools
- the resulting condensation creates clouds and rain that move north and south of the Equator
- at 30 degrees north and south of the Equator, the cold, dry air sinks, creating high pressure and clear skies
- when the sinking air reaches the Earth’s surface, it moves either back to the Equator or towards the poles
- at 60 degrees north and south of the Equator, the surface air meets colder air from the poles, which causes it to rise, creating a belt of low pressure
- the air rises and cools - at a high level, this moves either back to the Equator or towards the poles
- at the poles, the cool air sinks to the Earth’s surface, creating high pressure - the air then moves back towards the Equator
describe the global distribution of tropical storms
tropical storms cannot form more than 30 degrees north or south of the equator as the water is not warm enough and the Coriolis force not great enough
describe the formation of a tropical storm
- warm, moist unstable air above the ocean rises, creating an area of low pressure below
- surrounding cooler air is drawn into the area of low pressure, causing winds
- the col drawn in air now warms up and takes on moisture, causing it to rise
- the large mass of rising, warm air cools and condenses, forming large clouds and heavy rain
- latent heat released during condensation helps to power the storm
- as more air is drawn to the area of low pressure, the Earth’s rotation causes wind to spiral into the storms eye
- cooler, drier air sinks into the eye of the storm, creating calm conditions - prevailing winds then push the storm towards the land
- the storm continues to get bigger and stronger until it reaches land or colder seas
describe the structures and features of a tropical storm
- convection currents
- eyewall
- eye
- cool, dense air
- hurricane winds and rain
- warm, moist air
describe how climate change may affect the distribution of tropical storms
as sea temperatures rise, more of the worlds oceans will heat to above 27 degrees - therefore tropical storms may be able to develop in areas further north or south of the equator
describe how climate change may affect the intensity of tropical storms
as sea temperatures rise, storms will become more intense - the increased heat energy powers the storms, bringing higher rainfall and stronger winds
describe how climate change may affect the frequency of tropical storms
is it thought that the frequency of tropical storms may remain the same or decrease as the Earth gets warmer
describe the primary and secondary effects of a tropical storm
primary:
- high rainfall leads to flooding, particularly in coastal regions
- buildings and transport links are destroyed
secondary:
- diseases spread easily because of contaminated water and poor sanitation
- damage to infrastructure such as roads and power supplies may take a long time to repair
describe the immediate and long-term responses of a tropical storm
immediate:
- rescue any survivors and treat injuries
- evacuate anybody at risk before the storm
long-term:
- rehouse those that have lost their homes
- repair or rebuild damaged buildings
use a named example of a tropical storm to show its effects
typhoon haiyan: struck philippines, south east asia on 8th November 2013
primary effects:
- social: 50% of houses destroyed and 4.1 people homeless
- economic: damage cost was $12 billion US dollars
- environmental: 400 ml of rainfall caused flooding and many crops were destroyed
secondary effects:
- social: infection and disease spread due to contaminated water and power supplies were cut off
- economic: airport was badly damaged and fishing industry was disrupted as the leaked oil contaminated fishing water
- environmental: flooding caused landslides
use a named example of a tropical storm to show its responses
immediate responses:
- gov televised a warning for people to prepare and evacuate
- emergency aid supplies arrived three days later by plane
- gov set up a curfew to reduce looting
long-term responses:
- oxfam replaced many fishing boats
- more cyclone shelters were built
- 33 countries and international organisations pledged help
describe how monitoring, prediction, protection and planning can reduce the effects of tropical storms
- prediction: scientists use technology to predict when and where a storm is likely to occur - hurricane warnings give people advice
- protection: buildings can be constructed from reinforced concrete or built on stilts to protect against winds and flooding - flood defences can be built along rivers and coasts
- planning: disaster kits can be provided for people in high-risk areas - evacuation routes can help people away from danger quickly
give an overview of types of weather hazards experienced in the UK
- drought: a prolonged period of abnormally low rainfall, leading to a shortage of water
- heavy rain: a period of abnormally heavy rain
- heatwaves: a prolonged period of abnormally hot weather
- thunderstorms: a heavy rain storm accompanied by thunder and lightning
give an example of a recent extreme weather event in the UK to illustrate:
- causes
- social, economical and environmental impacts
- how management strategies can reduce risk
somerset levels flooding:
- causes: rivers had not been dredged in over 20 years and built up sediment had reduced their capacities and increased flood risk
- social: schools were closed and residents were evacuated to temporary housing
- economic: roads and rail links were damaged and businesses were forced to close
- environmental: debris from floodwater littered the region
management strategies:
- road levels were raised to prevent disruptions to transportation networks
- work was carried out to increase the capacity of the King Sedgemoor Drain
give evidence that weather is becoming more extreme in the UK
- rainfall is heavier, and storms are more intense and frequent
- temps are becoming more extreme: 2014 was the warmest year since 1910
