Tropical cyclones

Question 1

What do tropical cyclones need in order to be formed?

Answer 1

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.

Question 2

What is a tropical cyclone?

Answer 2

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)

Question 3

Why do tropical cyclones not form immediately in areas around the equator?

Answer 3

They require a rotational force from winds

Question 4

What is the ‘eyewall’ of a tropical cyclone?

Answer 4

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.

Question 5

What is the ‘eye’ of a tropical cyclone?

Answer 5

The circular area of a cyclones centre- relatively calm where clear skies are found here.

Question 6

What are the ‘rain bands’ of a tropical cyclone?

Answer 6

The clouds and precipitation is found here, where most rainfall is.

Question 7

What is the frequency of tropical storms in months June - November?

Answer 7

Found in the northern tropics

Question 8

What is the frequency of tropical storms in months November - April?

Answer 8

Found in the southern tropics

Question 9

Where must tropical cyclones be located and why?

Answer 9

5° - 20° North / South of the equator, as this allows the deflection of the Coriolis effect to occur.

Question 10

Describe how tropical storms are rotated?

Answer 10

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.

Question 11

What are tropical cyclones?

Answer 11

They are large rotating storms that form over oceans in tropical areas.
Their name depends on where in the world they’re from

Question 12

What are tropical cyclones known as in the Atlantic?

Answer 12

Hurricanes

Question 13

What are tropical cyclones known as from the Indian Ocean?

Answer 13

Cyclones

Question 14

What are tropical cyclones known as from the pacific?

Answer 14

Typhoons

Question 15

Describe the distribution of tropical storms

Answer 15

They are mainly found to the north and south of the equator
They affect mainly America / India
Mainly are around the pacific / Atlantic seas

Question 16

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?

Answer 16

They require warm temperatures, we call the months of higher cyclone activity ‘seasonal’

Question 17

Why is it impossible to predict how many storms can be formed in a season and how many will become full cyclones?

Answer 17

It depends how warm each individual year is.

Question 18

State the 5 hazards caused by tropical cyclones.

Answer 18

High winds, intense rainfall, storm surges, coastal flooding and landslides.

Question 19

Why are high winds a dangerous impact on society?

Answer 19

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.

Question 20

Why do tropical cyclones release large amounts of water over land?

Answer 20

They take up a large amount of water as they move across miles of open ocean.

Question 21

How can weather forecasters estimate the amount of rainfall expected to fall?

Answer 21

Based on how long the storm has been travelling over seas.

Question 22

What does intense rainfall lead to?

Answer 22

Flooding, damage to property / injury as fast flowing water can knock people over.

Question 23

How are storm surges formed by tropical cyclones?

Answer 23

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.

Question 24

What are impacts of storm surges?

Answer 24

It leads to beach erosion and the destruction of coastal habitats, it damages coastal defences and can contaminate farmlands / freshwater areas like lakes.

Question 25

How is coastal flooding caused by tropical cyclones?

Answer 25

The combination of intense rainfall and storm surges puts coastal areas at severe risk of flooding.

Question 26

What does coastal flooding effect?

Answer 26

It placed residents and properties under risk, it may disrupt farmlands which are raising livestock and growing foods, and can damage industries.

Question 27

Why is flooding an environmental danger?

Answer 27

The huge amount of saltwater being transferred overland can be stored underground and absorbed by plants or drank by animals. This may lead to poisoning.

Question 28

How are landslides caused by tropical cyclones?

Answer 28

Intense rainfall affects areas of high relief as well as coastal lowlands. High levels of rain saturate soils quickly and results in the sediment becoming heavier therefore it may no longer be able to hold its position, ultimately leading to it sliding.

Question 29

What are two impacts of landslides?

Answer 29

It can cause widespread devastation on settlements / properties at the base of the slope and can also cause river flooding as it may block river channels leading to the diverting of water.

Question 30

Define the term ‘ sustained winds’

Answer 30

This refers to the average wind speed over a period of 2 minutes, (based off the sustained wind speed)

Question 31

What is El Niño?

Answer 31

This is a naturally occurring weather event in the pacific. It is currently on a cycle between 2-11 years but can change.

Question 32

What are the impacts of El Niño?

Answer 32

It impacts weather patterns leading to more intense tropical storms and droughts.

Question 33

What is meant by the term, normal conditions? (El Nino / La Niña)

Answer 33

What the weather is normally like in the South Pacific

Question 34

What are the normal weather conditions near Australia and near South America?

Answer 34

Near America is it usually warm and dry and near South America it is usually cool and dry.

Question 35

What are El Niño conditions?

Answer 35

This is a reversal of the normal weather conditions ( cool + cry near Australia and warm + wet near South America)
-milder winters

Question 36

What are La Niña conditions?

Answer 36

A strengthening of the normal conditions (very warm and very wet often leading to flooding near australia, very dry and very cold near the west coast of South America, leading to droughts)