Weather Hazards

Question 1

How does the way the atmosphere circulate affect the Earth? Why?

Answer 1

It impacts global weather and climate patterns because the movement of the air around the globe is influences the temperature and humidity.

Question 2

What is atmospheric circulation?

Answer 2

Within the Earth’s atmosphere, the air is constantly moving in different directions because of the sun’s energy, differences in pressure, and the rotation of our Earth. These movements cause the air to circulate around the Earth, following generally predictable movements.

Question 3

What are the three distinct patterns of air circulation?

Answer 3

Circular air movements called cells:
1) The Hadley cell: at the equator - hot, moist air rises - moves to higher latitudes (30°) and sinks (to 0° - a.k.a the equator)
2) The Ferrell cell: at around 60° either side of the equator - moist air rises and travels to lower latitudes at around 30° where it sinks, along with air travelling from the equator
3) The Polar cell: at 60° North or South of the equator - moist air rises and travels to the poles (90°) where it sinks

Question 4

How is wind created?

Answer 4

When air particles move. Air particles will always move from an area of high pressure to an area of low pressure

Question 5

What is the Coriolis affect? How does this affect wind?

Answer 5

Wind is deflected in different directions due to the Earth spinning, so the winds end up travelling in a curved direction. This spinning effect is known as the Coriolis effect so the winds deflected right are in the Northern Hemisphere and winds deflected left are in the Southern Hemisphere.

Question 6

What happens when warm, moist air rises?

Answer 6

It creates an area of low pressure and creates cloudy and wet conditions.

Question 7

What happens when cold air rises?

Answer 7

It creates an area of high pressure and creates dry conditions.

Question 8

Where are low pressure belts?

Answer 8

• At the equator
• 60° either side of the equator

Question 9

Where are high pressure belts?

Answer 9

• 30° either side of the equator
• At the poles

Question 10

What do pressure belts and surface winds impact?

Answer 10

• Temperature
• Humidity

Question 11

What is the climate like at the equator?

Answer 11

Humid and very rainy due to the hot, moist air rising than condensing to form rain clouds.

Question 12

What is the climate like at the subtropics?

Answer 12

It is very dry due to dry air sinking forming areas of high pressure - in the day it is extremely hot but at night it is very cold due to no clouds being able to retain the heat.

Question 13

What is the climate like at the subpolar latitudes?

Answer 13

It is cloudy and wet due to the low pressure belt however it is not as warm due to the sun shining less directly there than it does at the equator.

Question 14

What is tropical storm?

Answer 14

It is very large and is formed in the tropic. They usually affect small islands and coastal regions.

Question 15

What are the characteristics of tropical storms?

Answer 15

They have high winds and torrential rain.

Question 16

What is a tropical storm called in different regions?

Answer 16

• Hurricane - USA, Latin America/The Caribbean
• Cyclone - Australia (Oceania), Madagascar
• Typhoon - India, Japan, the Philippines

Question 17

What are the conditions needed for tropical storms to form?

Answer 17

1) Ocean temperatures around 26° - 27° - this allows the storm to gain energy
2) A depth at least 50 km
3) Unstable air pressure - usually where high pressure and low pressure meet
4) The wind shear must have a swirling motion for the tropical storm to form but it cannot be too strong or the storm system will be ripped apart in early stages
5) It will form 5°-30° around the equator to have the ‘Coriolis Effect’

Question 18

What is the tropical storm formation?

Answer 18

1) Warm, moist air rises leaving an area of low pressure below - this causes warm air from the surroundings to move into this low pressure area and rise too. Overall, warm air is constantly rising and accumulating in the atmosphere.
2) When the warm air rises, it eventually cools - this moist air will then condense and form large thunderstorm clouds
3) The whole system is spinning due to the Coriolis Effect. In the southern hemisphere, the storm spins clockwise and in the northern it spins anticlockwise
4) The constant additions of energy from the warm air causes the storm to spin faster and generate higher wind speeds. At 75mph the storm can classed as a category 1 tropical storm
5) The storm develops an eye in the centre. This is an area of extremely low pressure (can be 15% lower pressure than areas outside the storm) where cool, dry air descends. The weather within the eye is relatively calm and cloud free.

Question 19

What surrounds the eye of the storm?

Answer 19

The eyewall - the most intense and powerful area of the storm. Warm, moist air rapidly rises here, with extremely high winds, thunder and lightning, and torrential rain. In very intense storms, sustained winds can reach up to 150mph and gusts can exceed 200mph.

Question 20

What happens when a storm reaches landfall?

Answer 20

The low pressure and high winds will cause a large amount of sea water to be pushed onto the coast, which is called a storm surge. When the storm reaches land, it no longer has a supply of energy and the eye eventually collapses and the storm dissipates. Heavy rain can persist for days.

Question 21

What is distribution?

Answer 21

Where the tropical storms are formed and where they move to.

Question 22

How is climate change affecting tropical storms?

Answer 22

• Since sea surface temperatures are rising where tropical storms are not usually active, tropical storms could potentially form in these areas in the future.
• In addition, with sea surface temperatures rising, the locations that typically develop tropical storms may expand to other regions.
• Scientists are further researching how the patterns of tropical storms are being affected.
• However, at the moment, studies show that climate change has not increased the frequency of tropical storms and that there has been no significant increase in regions that experience tropical storms.
• Some studies show that there may have even been a decrease.
• On the other hand, there is significant evidence that the intensity of tropical storms has been increasing due to climate change.
• Likely in the future, the number of Category 4 & 5 tropical storms will increase and wind speeds will increase by 10%

Question 23

What is an example of climate change affecting tropical storms?

Answer 23

In 2004, Hurricane Catarina hit the South-East coast of Brazil, which had never been struck by a tropical storm before. Sea surface temperatures were higher than average meaning a storm was able to form in the South Atlantic.

Question 24

What is frequency?

Answer 24

The number of tropical storms.

Question 25

What is the intensity of a storm?

Answer 25

How much power the tropical storm has.

Question 26

How is the intensity of a storm measured?

Answer 26

Using a scale labelled 1-5. Category 1 being the lowest intensity and Category 5 being the highest intensity.

Question 27

What is a PDI?

Answer 27

A power dissipation index which is a measure of a tropical storm’s intensity. A PDI accounts for a tropical storm strength, duration and frequency.

Question 28

What can tropical storms be damaging to?

Answer 28

1) People
2) The environment
3) The economy

Question 29

What is a primary effect?

Answer 29

The effects caused directly by the tropical storm.

Question 30

What is a secondary effect?

Answer 30

The effects that are a result of the primary effects.

Question 31

What does the term responses refer to?

Answer 31

How the local community, government and international organisations/governments react to a hazard the effects can be reduced as much as possible. Responses can either be immediate or long-term.

Question 32

What is an immediate response?

Answer 32

Actions taken as soon as the hazard has happened. (This can be up to 10 days.) Immediate responses aim to reduce loss of life, provide vital aid and resources (e.g. search and rescue, medical care, food and water, shelters).

Question 33

What is a long-term response?

Answer 33

Actions taken after the immediate responses when the effects of the hazard have been minimised. Long-term responses aim to restore normality and reduce risk in the future (e.g. rebuilding infrastructure and homes, cleaning up effects of hazard like debris, building defence mechanisms, setting up warning systems).

Question 34

What are the 4 ways to manage a tropical storm?

Answer 34

1) Monitoring
2) Predicting
3) Protecting
4) Planning

Question 35

How is monitoring used for tropical storms?

Answer 35

It is possible to track cloud formations and movements using satellite technology - scientists monitor areas where tropical storms usually form. It is also possible to monitor the route a tropical storm is taking to see if there is a potential for it to make landfall.

Question 36

How is predicting used for tropical storms?

Answer 36

By using monitoring and computer modelling, it is possible to predict the route if a tropical storm as well as the intensity up to days in advance. The population can be informed of the estimated time that they will be hit by the storm - these predictions become more reliable as the storm gets closer. It is also possible to predict how high a storm surge will be by analysing the intensity of the storm which helps to reduce risk for civilians by making them evacuate.

Question 37

How is protecting used for tropical storms?

Answer 37

By building and infrastructure design, for example:
* Sea walls built on coastlines to block storm surges
* Storm drains direct 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 stilts or on higher ground to reduce risk of flooding

Question 38

How is planning used for tropical storms?

Answer 38

Examples:
* Hazard Mapping - identifying areas of most risk
* Evacuation routes and safety protocols - creating evacuation routes and developing warning systems
* Raising awareness - if community is aware of risk they face from tropical storms, they can lower their risk by planning in advance

Question 39

What is weather?

Answer 39

The day-to-day conditions of the atmosphere at a specific place. (Such as temperature, amount of wind, cloud cover.)

Question 40

What is climate?

Answer 40

The average weather conditions of a specific region over a long period of time, usually 30 years.

Question 41

What is a weather hazard?

Answer 41

A weather event that is so extreme it causes risk to lives or property (the UK experiences different types of weather hazards although its climate is not considered extreme).

Question 42

What is happening to weather hazards in the UK?

Answer 42

They are becoming more frequent and intense in the UK because:
* There is more energy in the atmosphere which fuels storms
* It is getting hotter causing more intense and frequent periods of hot weather
* The way atmospheric circulation affects moisture and pressure is changing due to climate change and altering precipitation patterns
* Evidence of weather patterns in the UK getting stuck due to changing climate meaning we are experiencing prolonged weather events more frequently - sometimes the jet stream is blocked and becomes stuck which causes weather patterns to be stuck over the UK until it moves again which can cause heavy, prolonged rainfall or high temperatures for many weeks

Question 43

What is the UK’s weather controlled by?

Answer 43

The jet stream which is a fast-moving, strong wind current that flows in the upper atmosphere.