Extreme Weather - Hazardous Earth - Geography GCSE

What is a tropicle cyclone?

What is a tropicle cyclone?

A very large, spinning storm that forms in the tropics

What are some characteristics of tropical cyclone

• High winds

• Torrential rain

• Low pressure we

• Intense weather - rainfall

• Spinning Structure

• Strong winds

• Thunderstorms

Where does tropical cyclone often affect?

• Small islands

• Coastal Regions

Why does low pressure occur during a tropical cyclone?

Warm air rises and creates an updraught during the formation of a tropical cyclone, causing an area of low pressure to form

What is the difference between the pressure inside the tropical cyclone and the pressure on Earth?

Inside a tropical cyclone, the pressure is 950mb and the pressure on the Earth is 1013mb. The center of the storm, the eye can be 15% lower pressure than areas outside of the storm

Describe what happens in the eye wall of a storm?

• The strongest winds

• Thunder and lightning

• Torrential rain

In very intense storms, sustained winds can reach … and gusts can reach …?

240km/hour

320km/hour

Why do tropical cyclones rotate?

They rotate due to the spin of the earth

How does the rotation of tropical cyclone vary on which hemisphere of earth it is on?

in the south, they spin clockwise

the north, the spin anticlockwise

Describe the cross section of a tropical cyclone?

In the outer section is the rain band

then the eye wall

then the eye

Explain what happens in the rain band of a cyclone

• In the rainband of a cyclone, there is a band of clouds that wraps around the center of the storm. This band is characterized by heavy rainfall and strong winds.

• The rainband is formed as warm, moist air rises and condenses, creating clouds and precipitation. The strong winds within the rainband can cause significant rainfall and potential flooding in the affected areas.

Explain what happens in the eye wall of a cyclone?

• In the eye wall of a cyclone, the most intense and destructive weather conditions occur - heavy rainfall, intense updrafts and strong vertical motion

• It is a ring of thunderstorms surrounding the eye of the cyclone as warm air rises and rotates around the eye. Here, the wind speeds are the strongest, often exceeding 100 mph or more.

• The formation of powerful winds, torrential rain, and potential tornadoes. The eye wall is where the greatest damage and danger are typically experienced during a cyclone.

Explain what happens in the eye of a cyclone?

• The eye is a region of calm and relatively low pressure at the center of the storm. It is surrounded by the eyewall, which is a ring of intense thunderstorms.

• Within the eye, winds are light and skies are often clear. The air sinks and warms, creating a stable environment.

• It is important to note that entering the eye of a cyclone can be extremely dangerous, as the eyewall and its associated hazards lie just outside.

• It is colder and the dry air sinks down the eye. It is around 30 miles wide.

How tall is a cyclone?

Around 14km high

How wide is a cyclone?

Around 480km (300 miles) wide but can be up to 1500km+ wide

What are cyclones called in the USA and Latin America/The Caribbean? And when do they occur?

Hurricanes

Mid July to September

What are cyclones called in Australia and Madagascar? And when do they occur?

Cyclones

January - April

What are cyclones called in India, Japan and the Philippines? And when do they occur?

Typhoon

July to October

What conditions do cyclones need to form?

• They form between 5-15 degrees north or south of the equator

• In warm oceans

• Area of unstable air pressure

• mild winds

What is the source area?

This is the location that a tropical cyclone forms in is known as its source area

Describe the temperature needed for a tropical cyclone to form? and why these temperature are needed? When are these temperatures the most common?

Ocean temperature must be 26 - 27 degrees and at least 50 meters deep.

Warm water provides the storm with energy.

Storms form during late summer, when the ocean has had time to heat up.

Describe the air pressure needed for a tropical cyclone to form? and why these pressures are needed?

• areas of unstable air pressure - when low and high air pressures meet.

• so that warm air rises more readily and clouds can form (the air most also be humid for cloud formation)

• Warm air rises because it is less dense than cold air.

Describe the wind needed for a tropical cyclone to form?

• Wind must be present for the swirling motion to form, but not too strong or the storm system will be ripped apart in the early stages

What is Coriolis effect?

the effect of the Earth’s rotation on weather event

Explain the relationship between the Coriolis effect and cyclones

• Cyclones spin because the Earth is spinning.

• There is no Coriolis effect at the equator which is where cyclones can’t form so they form a certain distance away from it.

What is a cyclone track?

This is certain pathways that cyclones follow that are driven by the global wind circulation

How is the cyclone track followed?

They can be followed using satellite imagery as the cyclones are big enough to be seen from space

What are the steps for cyclone formation and death?

• Warm moist air rises, leaving an area of low pressure below. This causes warm air from surrounding to follow the same step. Overall causing warm air to continuously rise and accumulate in the atmosphere.

• When the warm rises. it cools and them condenses and form large thunderstorm clouds.

• Everything is spinning because of the Coriolis effect. The direction of it spinning depends on what hemisphere it is in.

• Warm air adds energy to the storm causing it to spin faster and generate high wind speed. At 75mph, the storm is now classified as a category 1 tropical cyclone.

• When the storm reaches a coast, the low pressure and high winds will cause a large amount of the sea water to be pushed onto the coast, called a storm surge

• When it reaches land, it no longer has a supply of energy and the eye eventually collapse and the storm dissipates. Heavy rain and persist for days.

What is the energy supply for a cyclone?

• warm

• moist air from the sea

What are the hazards from a tropical cyclone and what is some of their impacts ?

• High winds - strong enough to lift rods and bring down infrastructure, which can be very dangerous if they hit someone - lead to homelessness & loss of income as people’s livelihood destroyed & social disorder or conflicts

• Intense rainfall - over 100 cm of rain can fall in a single storm event (more than the UK’s annual rainfall) - electricity, water and communication destroyed

• Storm Surges - destroy homes, land and buildings. People can drown - lead to homelessness & loss of income as people’s livelihood destroyed & social disorder or conflicts. Trauma, stress and other mental health issues after the event

• Coastal flooding - damage coastal infrastructure and contaminate fresh water - people get diseases and it can lead to unhygienic conditions.

• Landslides - large amount of water can over saturate the ground and trigger landslides.

What factors influence a populations vulnerability to tropical cyclones?

• Education

• Wealth

• Location

• Climate Change

How can education affect a population vulnerability to cyclones?

• Some people are less educated no the risk they face from tropical cyclones, making them more vulnerable as they could be less unprepared

• Being aware of evac routes and being prepared (having emergency kits with first aid, food supplies, a whistle etc) makes people less vulnerable if a tropical cyclones does hit.

How can wealth affect a population vulnerability to cyclones?

• Poorer countries may not be able to respond to a tropical cyclone as effectively as a richer one

• Emergency services, reconstruction requires a lot of money. Poorer countries often rely on international aid.

• Poverty can force population to live in unsafe housing which is not built to withstand tropical cyclone making them vulnerable

• Wealthier countries have money to build defences, contrust cyclone resistant housing and develop widespread warning systems

How can climate change affect a population vulnerability to cyclones?

• Sea levels rise caused by climate change could make people more vulnerable to storm surges as the sea will be higher

• Could also affect the intensity of cyclones and could affect the distribution in the future making more people vulnerable

How can location affect a population vulnerability to cyclones?

• Those who live in prone area are more vulnerable to their impacts

• Populations in low lying coastal area are at higher risk of being affected by storm surges compared to those living higher up and further in land.

What are the three way countries can reduce the impacts of cyclone?

• Ensure the cyclone is monitored - satellite and forecasting technologies

• Warning systems and evac strategies for population

• Building physical defences

Explain how a country can use weather forecasting and satellite technology to track a cyclone?

• Since cyclones form away from land, it is possible to track cloud formation and movement using satellite tech.

• Scientist monitor source areas to see if one is on its way.

• Monitor the track a tropical cyclone is taking, to see if there is potential for the tropical cyclone to make landfall.

• Predict the the track and intensity of cyclone days in advance

• Population is informed the estimated time it may strike and is able to prepare in advance

• Prediction become more reliable as it gets closer

• Height of storm surge will be analysing the intensity of a storm

Explain how a country can use warning and evac strategies?

• evac routes and safety protocols - countries create evac routes and develop warning systems to ensure the population is prepared for a storm and will be alerted when one is coming

• use different forms of media

• raise awareness - tell people the risks and how to lower them

Some countries have very rural communities, that do not have any means of communication, making them vulnerable - to reduce their vulnerability, countries like Bangladesh are training people to go to these rural communities and warm them

Explain how a country can use physical defences to protect themselves and property from a cyclone?

• Sea wall can be built on coastlines to block storm surges

• Storm drains can be constructed to divert water after high levels of rainfall to reduce the risk of flooding

• Power lines, doors, windows, transformers etc. can be reinforced to be resistant to high winds

• Houses can be built on higher ground or even on stilts to reduce flooding risk

• Building hurricane proof houses - using stilts, making them out of concrete

What are advantages of weather forecasting and satellite technology to track cyclones?

1. Early Warning: Provide early detection and prediction of cyclones, allowing authorities to issue timely warnings and evacuate vulnerable areas, potentially saving lives.

2. Accurate Tracking: Enable precise tracking of cyclones, providing real-time information on their location, intensity, and movement.

3. Improved Preparedness: Weather forecasting and satellite technology allow for better preparedness by providing detailed information about the cyclone's path, strength, and potential impact. This enables communities to take necessary precautions, such as reinforcing infrastructure, securing supplies, and organizing evacuation plans.

4. Enhanced Response: Accurate forecasting and satellite imagery help emergency responders and relief organizations allocate resources effectively. They can identify areas at highest risk, prioritize rescue and relief efforts, and coordinate response operations more efficiently.

5. Scientific Research: Weather forecasting and satellite technology contribute to scientific research on cyclones, helping scientists understand their formation, behavior, and long-term patterns. This knowledge aids in improving forecasting models and developing more effective mitigation strategies.

What are disadvantages of weather forecasting and satellite technology to track cyclones?

1. Limited accuracy: Weather forecasting and satellite technology are not always 100% accurate in predicting the exact path and intensity of cyclones. There can be errors and uncertainties in the data collected and the models used for prediction.

2. Costly infrastructure: Maintaining and operating weather satellites and forecasting systems can be expensive.

3. Data limitations: Weather forecasting relies on data collected from various sources, including satellites. However, there may be gaps in data coverage, especially in remote or underdeveloped areas, which can affect the accuracy of cyclone tracking.

4. Time constraints: Cyclones can develop and intensify rapidly, making it challenging for weather forecasting systems to provide timely and accurate predictions. This can impact the effectiveness of evacuation plans and disaster preparedness.

5. Interpretation challenges: Interpreting the vast amount of data collected by satellites and weather forecasting systems requires skilled meteorologists. In some cases, the complexity of the data can lead to errors or misinterpretations, affecting the accuracy of cyclone tracking

What are advantages of using warning and evacuation routes to track cyclones?

1. Safety: By following designated evacuation routes, people can safely move away from the cyclone's path, reducing the risk of injury or loss of life.

2. Efficient Evacuation: Having pre-determined routes ensures a systematic and organized evacuation process, minimizing chaos and congestion.

3. Resource Allocation: Evacuation routes help authorities allocate resources effectively, such as transportation, shelters, and medical assistance, to areas that need them the most.

4. Communication: These routes facilitate clear communication between authorities and the public, ensuring that accurate and timely information is disseminated during cyclone events.

What are disadvantages of using warning and evacuation routes to track cyclones?

1. Limited capacity: The designated routes may not have the capacity to accommodate a large number of people, leading to congestion and delays during evacuation.

2. Predictability: Relying solely on predetermined routes may not account for sudden changes in the cyclone's path or intensity, potentially leaving some areas vulnerable.

3. Accessibility: In some cases, the designated routes may not be easily accessible to all individuals, particularly those with disabilities or limited mobility.

4. False sense of security: Strict adherence to evacuation routes may create a false sense of security, causing people to overlook other important safety measures or underestimate the severity of the cyclone.

What are advantages of using physical defences to protect places from cyclones?

1. Structural Protection: Physical defenses such as seawalls, breakwaters, and levees can provide a physical barrier against the destructive force of cyclones, reducing the impact on buildings and infrastructure.

2. Erosion Prevention: Physical defenses can help prevent erosion of coastal areas caused by cyclone-induced storm surges, preserving the natural environment and reducing the risk of further damage.

3. Safety and Human Protection: Physical defenses can enhance the safety of residents and reduce the risk of casualties during cyclones by providing a buffer zone and preventing direct impact on populated areas.

4. Economic Benefits: By protecting infrastructure, physical defenses can help minimize damage and disruption to businesses, reducing the economic impact of cyclones on local communities and the wider economy.

5. Long-term Resilience: Implementing physical defenses can contribute to the long-term resilience of communities by reducing the frequency and severity of damage caused by cyclones, allowing for quicker recovery and minimizing the need for costly reconstruction efforts.

What are disadvantages of using physical defences to protect places from cyclones?

1. Cost: Building and maintaining physical defenses such as seawalls, levees, or barriers can be expensive, requiring significant financial resources.

2. Environmental Impact: Constructing physical defenses may disrupt natural ecosystems, alter coastal processes, and harm marine life. It can also lead to erosion and sedimentation issues.

3. Limited Effectiveness: Physical defenses may not provide complete protection against cyclones, especially in the case of extremely powerful storms or storm surges. They can be breached or overwhelmed, leaving areas vulnerable.

4. Maintenance and Upkeep: Physical defenses require regular maintenance and repairs to remain effective. Neglecting maintenance can lead to deterioration and reduced effectiveness over time.

5. False Sense of Security: Relying solely on physical defenses may create a false sense of security, leading to complacency and inadequate preparedness for other aspects of cyclone impacts, such as heavy rainfall and inland flooding.