Tropical Storms

Question 1

What happens in Global atmospheric circulation?

Answer 1

The movement of air across the planet occurs in a specific pattern. The whole system is driven by the equator, which is the hottest part of the Earth. Air rises at the equator, leading to low pressure and rainfall.
When the air reaches the edge of the atmosphere, it cannot go any further and so it travels to the north and south. The air becomes cold and falls to create high pressure and dry conditions at around 30° north and south of the equator. Large cells of air are created in this way. Air rises again at around 60° north and south and descends again around 90° north and south.
Global atmospheric circulation creates winds across the planet and leads to areas of high rainfall, like the tropical rainforests, and areas of dry air, like deserts.

Question 2

What is a tropical storm?

Answer 2

A tropical storm is a very powerful low-pressure weather system which results in strong winds (over 120 km/h) and heavy rainfall (up to 250 mm in one day). Tropical storms have different names depending on where they occur in the world. In the US and the Caribbean they are known as hurricanes, in South Asia - cyclones, in East Asia - typhoons and in Australia they are known as willy-willies. They all develop in the same way and have the same characteristics.

Question 3

What is condensation?

Answer 3

Condensation is a change of state in which gas becomes liquid by cooling.

Question 4

What is Coriolis force?

Answer 4

Apparent force, due to the spinning of the Earth, which deflects movement of particles and wind.
The Coriolis force caused by the rotation of the Earth causes the tropical storm to spin.

Question 5

What is a cumulonimbus?

Answer 5

A type of large, dense, tall, grey cloud which produces rain, hail, or snow. Large towering cumulonimbus clouds surround the eye. These are caused by warm moist air condensing as it rises. This leads to very heavy rainfall and wind speeds of up to 320 km/h.

Question 6

What is meant by displace?

Answer 6

A situation when a person or people are forced to leave their home or country, due to war or a natural disaster.

Question 7

What are mangrove forests?

Answer 7

Tropical evergreen trees which help protect coastal zones.

Question 8

What is the eye?

Answer 8

The central part of the tropical storm is known as the eye. The eye is usually 32-48 km across. It is an area of light wind speeds and no rain. It contains descending air.

Question 9

How do tropical storms develop?

Answer 9

Tropical storms form between approximately 5° and 30° latitude. Because of easterly winds they initially move westward.
The air above the warm ocean is heated. Once the ocean water reaches at least 27°C, the warm air rises quickly, causing an area of very low pressure.
As the air continues to rise quickly it draws more warm moist air up from above the ocean leading to strong winds.
The rapidly rising warm air spirals upwards, cools, condenses and large cumulonimbus clouds form.
These clouds form the eye wall of the storm and produce heavy rainfall.
In the centre of the storm, cold air sinks forming the eye of the storm - here, conditions are calm and dry.

Question 10

How do tropical storms stop?

Answer 10

When tropical storms reach a land surface, they begin to lose their energy and die out. This is because they are no longer receiving heat energy and moisture from the ocean, which is needed to drive the storm.

Question 11

What are the impacts of climate change?

Answer 11

Climate change could lead to more locations being affected by tropical storms. Warmer seas could cause the source areas (the areas where the storms would form) to extend further north and south of the equator.
It’s unclear whether climate change will increase or decrease the number of tropical storms, but climate models predict that their intensity may increase.

Question 12

What factors may play a part in increasing tropical storms impacts?

Answer 12

warmer ocean surface temperatures and higher sea levels
wind speeds potentially increasing 2-11 per cent
rainfall rates during these storms are projected to increase by about 20 per cent

Question 13

How does sea level affect tropical storms?

Answer 13

In addition, sea level rise is likely to make tropical storms more damaging with increases in coastal flooding and subsequent storm damage along coasts. Low-lying coastal communities where the population density is high and the income level low are most at risk. More people living in coastal communities in the future will mean that more people will be affected.

Question 14

What are methods of predicting storms?

Answer 14

Centres use satellite images, various weather instruments and computer-based prediction modelling to detect and track tropical storms. When tropical storms affecting populated coastal areas are predicted, the centre issues warnings.
Warnings give information to the local authorities of places likely to be in the tropical storm’s path, in order to make preparations to protect public safety. These are broadcast over TV and radio and warnings can be issued to smart phones. People in vulnerable coastal areas are usually advised to secure their property and move away.Reinforced aircraft, fitted with various scientific instruments, fly through and over tropical storms to collect data. This can be used to help track and predict the path of a tropical storm.

Question 15

What was typhoon haiyan?

Answer 15

Typhoon Haiyan was a tropical storm that affected the Philippines in South East Asia in November 2013. It was one of the strongest tropical storms ever recorded with winds of 313 km/h. In some areas, 281.9 mm of rainfall was recorded, much of which fell in under 12 hours. Waves of up to 7 m in height battered the coast. The Philippines is a fairly poor part of the world with minimal investment in prediction, planning and protection schemes.

Question 16

What were economic impacts of typhoon haiyan?

Answer 16

The overall economic impact of Typhoon Haiyan is estimated at $5.8 billion (£3.83 billion).
Six million workers lost their sources of income.
Major rice, corn and sugar-producing areas for the Philippines were destroyed affecting the country’s international trade and farmers’ incomes.
The city of Tacloban’s airport was severely damaged, affecting business and tourism.
Fishing communities were severely affected with the storm destroying 30,000 boats and associated equipment.

Question 17

What were social impacts of typhoon haiyan?

Answer 17

More than 7,000 people were killed by Typhoon Haiyan.
1.9 million people were left homeless and more than 6,000,000 displaced.
There were outbreaks of disease due to the lack of sanitation, food, water, shelter, and medication.
Less affected areas reported that their populations more than doubled after the typhoon with the influx of refugees.
The Tacloban city government was devastated, with only 70 people at work in the immediate days after the disaster compared to 2,500 normally. Many were killed, injured, lost family or were simply too traumatised to work.
In the city of Tacloban, widespread looting took place in the days following the typhoon.

Question 18

What were environmental impacts of typhoon haiyan?

Answer 18

Widespread floods damaged and in many cases destroyed homes and businesses in coastal areas.
The Philippine government estimated that about 71,000 hectares of farmland was affected.
Thousands of trees were uprooted leading to a massive release of carbon dioxide and loss of habitat with resulting effects on wildlife.
Flooding knocked over Power Barge 103 causing an oil spill affecting mangrove ecosystems.
Major roads were blocked by trees, and were impassable.

Question 19

What were responses to typhoon haiyan?

Answer 19

Even though the loss of life was significant, it could have been much worse if not for the efforts of PAGASA, the Philippines’ meteorological agency. It broadcast warnings two days before Typhoon Haiyan hit, leading to the evacuation of approximately 750,000 residents.
The Philippines formally declared ‘A State of National Calamity’ and asked for international help, one day after Typhoon Haiyan hit the country.
The UK government provided food, shelter, clean water, medicine and other supplies for up to 800,000 victims.
Several charities provided emergency aid such as water, food and shelter. In the longer term, they are helping people get their livelihoods back, for example by repairing fishing boats or distributing rice seeds.
The United Nations launched an international aid appeal in December 2013 for £480m to finance the humanitarian relief effort for 2014.
In 2014, the Philippines commissioned billboards in some of the world’s prime advertising sites such as New York’s Times Square and London’s Piccadilly Circus to thank people for their help after Typhoon Haiyan.