Tropical Storms ⛈️🌬️ (+ Effect Of Climate Change)

Question 1

Where do tropical storms develop?

Answer 1

Between 5º and 30º north and south of the equator

Question 2

What conditions do they need to develop?

Answer 2

• sea temperature is 27ºC or higher
• wind shear (difference in wind speed) between higher and lower parts of the atmosphere is low

Question 3

How do they form?

Answer 3

• warm surface water evaporates, rises and condenses into clouds
• releases huge amounts of energy, producing powerful storms
• rising air creates an area of low pressure, which increases surface winds
• Low wind shear prevents clouds breaking up as they rise, so the storm stays intact

Question 4

What happens after they’ve formed?

Answer 4

• easterly winds near the equator move them towards the west
• storm spins due to Coriolis effect
• as the storm moves over the ocean, the energy from the warm water strengthens the storm, so wind speed increases
• storms lose strength when they move over land or cooler water, because energy supply is cut off

Question 5

When and where do most tropical storms occur?

Answer 5

Northern Hemisphere - August to October
Southern Hemisphere - December to April

Question 6

Key points to know?

Answer 6

• circular in shape
• hundreds of km wide
• last 7-14 days
• spin anticlockwise (northern hemisphere)
• spin clockwise (southern hemisphere)

Question 7

What are the key features of a tropical storm?

Answer 7

• eyewall
• eye
• winds

Question 8

What is the eye of the storm?

Answer 8

Centre of the storm
Up to 50km across
Caused by descending air
Low pressure, light winds, no clouds or rain, high temperature

Question 9

What is the eyewall?

Answer 9

Spiralling rising air, very strong winds (160km/h), storm clouds, torrential rain, low temperature

Question 10

What happens towards the edges of the storm?

Answer 10

Wind speed falls, small and more scattered clouds, less intense rain, temperature increases

Question 11

How much have global average sea surface temperatures risen?

Answer 11

By 0.9ºC since 1880 and are expected to rise even more as a result of climate change

Question 12

How will climate change affect the frequency of tropical storms?

Answer 12

• oceans will stay 27ºC or higher for longer each year, so there’s a longer window for them
• could mean more storms each year
• in the Atlantic, the number of tropical storms has increased. 16/24 years have had more tropical storms on average

Question 13

How will climate change affect the distribution of tropical storms?

Answer 13

As the average temp rises, more of the world’s oceans will get to be a over 27ºC - may mean they can form in areas which have never experienced them before (e.g. at higher latitudes)

Question 14

How will climate change affect the intensity of tropical storms?

Answer 14

Higher sea surface temps are likely to result in more evaporation and increased cloud formation, so more energy is released. This could make the storms more powerful.
In the Atlantic, 2014-2018 had almost twice as many major storms as 1970-1975!

Question 15

What are some ways to reduce the effects of tropical storms?

Answer 15

• prediction and monitoring
• planning
• protection

Question 16

How can we use prediction and monitoring to reduce the effect of tropical storms?

Answer 16

• monitored using radar, satellites, aircraft
• computer models can be used to calculate a path for the storm
• predicting where and when they’ll happen gives people time to evacuate

Question 17

How can planning be used to reduce the effect of TS?

Answer 17

• future developments e.g. new houses can avoid high-risk areas
• governments can plan evacuation routes
• emergency services can prepare

Question 18

How can we use protection to reduce the effect of tropical storms?

Answer 18

• buildings can be designed to withstand winds and surges
• flood defences can be used