Topic 2a: Tropical Cyclones PAPER ONE Flashcards
What are the brief reasons that tropical cyclones are a natural weather hazard?
High winds
Intense rainfall
Storm surges
Coastal flooding
Landslides
Explain TC winds
- Over 119 kph
- Can blow off house roofs, destroy crops and uproot trees
- Can pick up items and hurl them at buildings/people
Explain TC rainfall
- Over 200mm in a few hours
- Damages crops + causes flooding
Explain TC Storm Surges
- Low air pressure in TC allows sea surface to rise by several metres
- Water is driven onshore (flooding)
Explain TC Coastal Flooding impacts
(caused by storm surges)
- Damages infrastructure = economic loss
- Flooded homes + businesses
- Impacts tourism by damaging facilities
- Economic loss due to electricity failure (firms can’t contact customers)
What is a tropical cyclone?
Intense low pressure weather system forming between tropic of Cancer and Capricorn
Explain the formation of a tropical cyclone
What are the characteristics of tropical cyclones?
- Very low air pressure produced by rapidly rising air
- Strong winds produced by a rapid convectional rise of warm air produced by solar heating
- Additional latent heat is released into the air when water vapour condenses into water
- Acceleration is produced by spin due to Coriolis deflection
- Cumulonimbus clouds form as rising air cools + water vapour condenses
What is the distribution of tropical cyclones?
8degrees - 20degrees North/south of equator
Regions where sun heated water above 27’C and where Coriolis deflection is strong enough to produce spin
Do tropical cyclones form along the equator? - why?
NO - No Coriolis deflection
What is the frequency of tropical cyclones?
- Form when the sun has sufficiently warmed the ocean
- Northern hemisphere: June - November
- Southern hemisphere: January - March
- About 80 form each year
