Tropical cyclones Flashcards
What do tropical cyclones need in order to be formed?
70 metres deep or more within sea depths
Above 26°C in sea for several days
Occur around the equator where trade winds are formed.
What is a tropical cyclone?
A very powerful, low-pressure weather system which results in strong winds (over 120 km/h) and heavy rainfall (up to 250mm in one day)
Why do tropical cyclones not form immediately in areas around the equator?
They require a rotational force from winds
What is the ‘eyewall’ of a tropical cyclone?
The mass of clouds that whirls around in the eye of a hurricane, where the destructive force of the storm is most intense / has the fastest winds.
What is the ‘eye’ of a tropical cyclone?
The circular area of a cyclones centre- relatively calm where clear skies are found here.
What are the ‘rain bands’ of a tropical cyclone?
The clouds and precipitation is found here, where most rainfall is.
What is the frequency of tropical storms in months June - November?
Found in the northern tropics
What is the frequency of tropical storms in months November - April?
Found in the southern tropics
Where must tropical cyclones be located and why?
5° - 20° North / South of the equator, as this allows the deflection of the Coriolis effect to occur.
Describe how tropical storms are rotated?
Trade winds converging within the tropics causes the air to rise, therefore the cyclones are formed some distance away from the equator allowing the Coriolis effect to move the storm, rotating it.
What are tropical cyclones?
They are large rotating storms that form over oceans in tropical areas.
Their name depends on where in the world they’re from
What are tropical cyclones known as in the Atlantic?
Hurricanes
What are tropical cyclones known as from the Indian Ocean?
Cyclones
What are tropical cyclones known as from the pacific?
Typhoons
Describe the distribution of tropical storms
They are mainly found to the north and south of the equator
They affect mainly America / India
Mainly are around the pacific / Atlantic seas
Why are tropical cyclones
usually formed through months June to November in the northern tropics and through months November to April in the southern tropics?
They require warm temperatures, we call the months of higher cyclone activity ‘seasonal’
Why is it impossible to predict how many storms can be formed in a season and how many will become full cyclones?
It depends how warm each individual year is.
State the 5 hazards caused by tropical cyclones.
High winds, intense rainfall, storm surges, coastal flooding and landslides.
Why are high winds a dangerous impact on society?
Production of winds over 119km per hour. These cause severe damage to buildings, trees can be uprooted and smaller constructions, like sheds and beach huts are moved. This can cause injury or loss of life.
Why do tropical cyclones release large amounts of water over land?
They take up a large amount of water as they move across miles of open ocean.
How can weather forecasters estimate the amount of rainfall expected to fall?
Based on how long the storm has been travelling over seas.
What does intense rainfall lead to?
Flooding, damage to property / injury as fast flowing water can knock people over.
How are storm surges formed by tropical cyclones?
A tropical cyclone creates lots of low pressure, causing rising sea levels. Combining with the winds, large water masses travel over land, therefore a large force is inflicted on the land.
What are impacts of storm surges?
It leads to beach erosion and the destruction of coastal habitats, it damages coastal defences and can contaminate farmlands / freshwater areas like lakes.
