Weather Hazards Flashcards
What is global atmospheric circulation?
- Drive the world’s weather patterns
- Involves individual circular air movements called ‘cells’
- Cells all join to for overall circulation of Earth’s atmosphere
What causes low and high pressure in the air?
air RISING from the ground surface forms LOW PRESSURE, air SINKING to the ground surface forms HIGH PRESSURE
What do certain areas of the world call tropical storms?
USA and Caribbean - Hurricanes
South-East Asia and Australia - Cyclones
Japan and Philippines - Typhoons
Under what conditions can tropical storms form?
- 27 degrees oceans
- Summer and Autumn, when temps are highest
- 5-15 degrees North and South of Equator
- Intense heat makes air unstable, which is important for rising of air
How are tropical storms formed?
- Strong upward movement of air draws water vapour up from warm ocean surface
- This rises, cools and condenses to form thunderstorm clouds
- As the air condenses it releases heat which gives the storm energy. Heat also causes more water vapour to rise from the warm ocean surface
- Several smaller thunderstorms join to form a giant spinning tropical storm (if wind speeds reach 120kmph its a tropical storm)
- Storm develops an eye at centre, where air descends rapidly. Outer edge of eye wall is where storm is most violent.
- As storm is carried across ocean by winds, it gains energy and strength
- When it reaches land, the energy source is cut off, and friction between the storm and the land slows it down so it begins to weaken and die
How could climate change affect the FREQUENCY of storms?
Frequency of storms may decrease
How could climate change affect the distribution of storms?
Areas of usually colder water may experience it as the temperatures rise
How could climate change affect the intensity of storms?
It could increase the INTENSITY of tropical storms
Primary Effects of TYPHOON HAIYAN
- 6300 killed
- 600,000 displaced
- 40,000 homes destroyed
- 90% of Tacloban City destroyed
- 30,000 fishing boats destroyed
- Widespread flooding (400m rainwater)
Secondary Effects of TYPHOON HAIYAN
- 6 million lost their source of income
- Flooding caused land slides, covering roads and cutting off remote communities
- Outbreak of disease due to lack of food and water
- Violence and looting broke out in Tacloban
- Children could not go to school
How can we reduce effects of Tropical Storms?
- Monitoring and Prediction
- Protection
- Planning
How does Monitoring and Prediction reduce effects of tropical storms? Examples?
- Storms can be predicted through monitoring data, so warnings can be given, including :
- Hurricane Watch (hurricane conditions are possible)
- Hurricane Warning (hurricane conditions are expected and people should evacuate)
How does Protection reduce the effects of tropical storms? EXAMPLES?
- Windows, doors and roofs reinforced to withstand strong winds
- Storm drains to prevent flooding
- Sea walls to protect from storm surge
- Houses built on stilts to avoid storm surge effects
- Houses built on raised ground, storm surge
- Construction with strong concrete
How does Planning reduce the effects of tropical storms?
- Raises individual awareness about the potential dangers and how to respond
How have Monitoring, prediction, planning and protection helped a country in the past?
- BANGLADESH
- Early warning, cyclone shelters, awareness
- Greatly reduced deaths from 500,000 to 4,000
