3.1 Tropical Revolving Storms

Question 1

What are the Characteristics of Tropical revolving Storms?

Answer 1

The eye is located in the centre and it is calm however the most intense winds and rainfall are found at the eye wall and they gradually get weaker towards the edges.

Tropical revolving storms can bring torrential rain fall, storm surges and extreme winds exceeding 74 mph

Question 2

What are the conditions required for a TRS to form?

Answer 2

• Forms over a warm ocean 27oC, cluster of storms
• Always form over oceans
• Low wind sheer
• Strong vertical currents (Low pressure)
• They generally occur at the end of the summer season when sea
  temperatures are at their highest
• 5 - 20 degrees above or below the equator

Question 3

Explain why these conditions are necessary for the formation of a TRS.

Answer 3

Provides the initial heat source air to warm and rise. Oceans provide a reduced friction surface for the TRS to move over.

This is because they need a huge volume of water to form and this scale of water can only be found in oceans

Wind shear makes it difficult for the storm to maintain a straight vertical spiral of warm air ascent, weakening the updraft leading to the collapse of the storm at the vortex

This rising air creates an updraft that helps to sustain the storm’s circulation.

Oceans warm up gradually over the summer and are the hottest at the end of the summer.

This is due to the Coriolis effect (earths rotation) which is the strongest slightly above and below the equator but not on it.

Question 4

Name the 8 steps for the formation of a TRS.

Answer 4

1) Solar radiation warms the ocean by being absorbed by water.
2) Intense and consistent solar radiation between the Tropics heats up ocean water to 27oC, facilitating tropical storm formation.
3) Warm ocean heat causes rapid air rising and high evaporation rates.
4) Rising air creates low pressure, drawing in surrounding air and generating stronger winds.
5) Warm, moist air rises, cools, and condenses, forming towering cumulonimbus clouds.
6) Coriolis effect deflects rising air, causing spiral formation and central eye development.
7) Storms migrate slowly across oceans towards land.
8) Passing over land deprives tropical storms of their energy source, leading to their dissipation.

Question 5

What are the names of the different Tropical revolving storms and describe their distribution.

Answer 5

Hurricanes - Found almost entirely on the East and West coasts of Northern and Central America, predominantly in the Atlantic.

Cyclones - Found in the Indian ocean and southern pacific affecting countries such as Australia, India and Fiji.

Typhoons - Found in the northwest Pacific ocean affecting countries such as Japan, China and the Philippines.

Question 6

How are storms measured?

Answer 6

They are categorised by wind speed (mph) on the Saffir Simpson scale.

Tropical depression - <39
Tropical storm - 39-73
Tropical revolving storms:
1) 74-95
2) 96-110
3) 111-129
4) 130-156
5) >156

Question 7

What are the short term impacts of a Tropical revolving storm?

Answer 7

Short term impacts:
- Property damage due to flooding from rains, storm surges and
winds
- Loss of life
- Disruption of services such as electricity, water, communication and
transport

Question 8

What are long term impacts of a Tropical revolving storm?

Answer 8

Long term impacts:
- Economic losses due to rebuilding infrastructure
- Health impacts such as the spread of waterborne diseases and an
impact on mental health
- Increased resilience since new technologies can be implemented to
mitigate the impacts if another TRS were to occur such as flood
walls and early warning systems.