3.1.1.3 Weather hazards Flashcards
What does global atmospheric circulation cause?
Causes ares to have some types of weather more than other - affect earth’s climate
What are winds essentially?
Are large scale movements of air caused by differences in air pressure
What are differences in air pressure caused by?
Differences in temperature between equator and poles
Winds move from areas of … to areas of …
Winds move FROM the areas high pressure TO the areas of low pressure
What are winds parts of?
Winds are parts of global atmospheric circulation loops (or cells)
What are 2 things global atmospheric circulation loops have and what do they create?
- Warm rising air = creates low pressure belt
2. `Cool falling air = creates high pressure belt
How many loops are in each hemisphere?
3
Global Atmospheric Circulation: Describe stage 1 - at the equator
- At the equator, the sun warms the Earth = transfers heat to air above = causing it to rise
- This creates low pressure belt with rising air, clouds and rain
Global Atmospheric Circulation: Describe stage 2 - as the air cools
As air rises it cools and moves out 30° north and south of equator
Global Atmospheric Circulation: Describe stage 3 - at 30° north and south of equator
At 30° north and south of equator, cool air sinks = creating high pressure belt with cloudless skies and very low rainfall
Global Atmospheric Circulation: Describe stage 4 - as cool air reaches ground surfaces
Cool air reaches ground surfaces and moves as surface winds either back to equator or towards poles
What are trade winds?
Surface winds blowing towards equator
What do trade winds do?
They blow from SE in southern hemisphere and from NE in northern hemisphere
What are westerlies?
Surface winds blowing towards poles
What do westerlies do?
They blow from NW in southern hemisphere and from SW in northern hemisphere
At the equator, what happens to trade winds & what does this cause them to do?
These trade winds meet and are heated by sun causes them to rise and form clouds
Global Atmospheric Circulation: Describe stage 5 - at 60° north and south of equator
- 60° north and south of equator the warmer surface winds meet colder air from poles
- Warm air is less dense than cold air so it rises, creating low pressure
Global Atmospheric Circulation: Describe stage 6 - some of the air moves
Some of air moves back towards equator, rest moves towards poles
Global Atmospheric Circulation: Describe stage 7 - at poles cool air
- At poles cool air skins, creating high pressure
- High pressure air is drawn back towards equator as surface winds
What are tropical storms?
Intense low pressure weather systems with heavy rain and strong winds that spiral around the centre
Give 3 names that tropical storms are known as
Hurricanes, typhoons and cyclones
When do tropical storms develop (give 2 conditions)
- When sea temperature is 27°C or higher (warm)
- When wind shear between higher and lower parts of atmosphere is low
What is wind shear?
The difference in wind speed
What makes a tropical storm powerful?
The amount energy it releases which comes from warm, moist air rising and condensation occurring
What does rising air create?
Rising air creates an area of low pressure, increases surface winds
Why do tropical storms move towards west?
Because of easterly winds near equator
What causes the storms to spin?
Earth’s rotation deflects paths of winds
How does a tropical storm get stronger?
Due to energy from warm water = wind speeds increase
Why do tropical storms lose their strength when they move over land or cooler water?
Because energy supply from warm water is cut off
Where do most tropical storms occur and why?
Between 5° and 30° north and south of equator - any further from equator and water isn’t warm enough
Which hemisphere do most tropical storms occur?
Majority of storms occur in northern hemisphere (especially over the Pacific)
What time of year do most tropical storms occur and why?
In late summer and autumn, when sea temperatures are highest
Name 3 features of tropical storms
Circular in shape, 100s km wide and usually last 7-14 days
Which way do they spin in the northern hemisphere?
Anticlockwise
Which way do they spin in the southern hemisphere?
Clockwise
What is centre of the storm called?
An eye
How big is storm’s eye?
Up to 50 km across
What is a storm’s eye caused by?
Descending air
Name 5 things/conditions that are found in a storm’s eye?
- Very low pressure
- Light winds
- No clouds
- No rain
- High temperature
What happens towards the edges of the storm? Name 4 things
- Wind speed falls
- Clouds become smaller and more scattered
- Rain becomes less intense
- Temperature increases
What is the eye of a storm surrounded by?
An eyewall
What happens in an eyewall? Name 5 things
- Very strong winds
- Spiralling rising air
- Storm clouds
- Torrential rain
- Low temperature
Name and explain 3 ways how climate change may affect tropical storms
- More world oceans could be above 27 °C = more places in world may experience tropical storms
- Oceans will stay 27°C or higher for more of the year = so number of tropical storms each year could increase
- Higher temperatures also mean tropical storms will be stronger = cause more damage
Name 6 primary effects of tropical storms
- Buildings are bridges are destroyed
- Rivers and coastal areas flood
- People drown, or they’re injured or killed by debris that’s blown around
- Roads, railways, ports and airports are damaged
- Electricity cables are damaged, cutting off supplies
- Sewage overflows due to flooding = contaminates water supplies
Name 5 secondary effects of tropical storms
- People are left homeless which can causes distress, poverty and ill health or death due to lack of shelter
- There’s a shortage of clean water and a lack of proper sanitation - makes it easier for diseases to spread
- Roads are blocked or destroyed so aid and emergency
vehicles can’t get through - Businesses are damaged or destroyed = causing unemployment
- Can be shortages of food if crops are damaged, livestock are killed or supply lines are blocked
If there are more settlements build and businesses set up in area, why would there be a greater effect (tropical storm)?
Because there’s more people and properties to be affected by tropical storm
Name 7 immediate responses to a tropical storm
- Evacuate people before storm arrives
- Rescue people who have been cut off by flooding and
treat injured people - Set up temporary shelters for people whose homes have been flooded or damaged
- Provide temporary supplies of water, food, electricity, gas and communications systems (if regular supplies shave been damaged)
- Recover any dead bodies to prevent spread of disease
- Foreign governments or NGOs may send aid workers, supplies, equipment or financial donations to the area
- Tech companies may set up disaster response tools, allowing damage to be recorded, people to confirm their safety and alerts about areas at risk from storms to be shared
Name 7 long-term responses to a tropical storm
- Repair homes or rehouse people who have been displaced due to damaged buildings
- Repair or replace damaged infrastructure
- Repair and improve flood defence systems (e.g. Levees and flood gates)
- Improve forecasting techniques to give people more warning in the future
- Provide aid, grants or subsidies to give people more
warning in the future - Promote economic recovery in the area and encourage people to return to the area (e.g. tax breaks)
- Improve building regulations so more buildings withstand hurricanes or change planning rules so homes can’t be built in most risky areas
Name 7 weather hazards experienced in the UK
- Rain
- Wind
- Snow and Ice
- Thunderstorms
- Heatwaves
- Hailstorms
- Droughts
What can flooding lead to? Name 3 things
- Disrupt transport networks
- Damage homes & processions
- Cause death by drowning
- Force businesses to close
What can snow and ice cause? Name 3 things
- Causes injures ← slipping & deaths due to cold
- Schools and businesses forced to shut & major disruption to road, rail and air travel = economic impacts
- Cold snaps = damage crops
What are gales?
Strong winds
What can strong winds do? Name 3 things
- Damage properties
- Disrupt transport
- Uprooted trees & debris = injure/kill people
- Damage forests
Where are winds strongest in the UK?
Strongest in coastal areas - west coast & upland
When and where are thunderstorms most common in the UK?
In summer in south and east of UK
What can thunderstorms cause? Name 2 things
- Lightning = occasional death
- Fires = damage properties & environment
What can droughts cause?
Water supply low = economic impacts like crop failures
What can droughts be prevented/how are they being prepared for?
Rules to conserve water have been added
What can hailstorms do? Name 3 things
Driving dangerous, damage properties & destroy crops
What are 3 effects of heatwaves?
- Deaths from heat exhaustion or breathing difficulties (pollution builds up in air)
- Disruption to transport from rails buckling or roads melting = economic impacts
- Tourism industry may benefit from better weather
Name 3 ways of reducing the effects of tropical storms
- Prediction
- Planning
- Protection
What do scientists use to monitor storms?
- Scientists use data from things like radar, satellites and
aircraft to monitor storms - Computer models are then used to calculate a predicted path for storm
Why is predicting where and when a tropical storm is going to happen useful?
Gives people time to evacuate and protect their homes and businesses e.g. Boarding up windows
Name 3 ways of planning for a tropical storm and how they will help
- Future development e.g. new houses can be planned to avoid the areas most at risk
- Emergency services can train and prepare for disasters (e.g. practising recusing propel from flooded area with helicopters) = reduces number of people killed
- Governments can plan evacuation routes to get people
away from storms quickly
Name 2 ways of protecting an area from the effects of a tropical storm?
- Buildings can be designed to withstand tropical storms e.g. by using reinforced concrete
- Flood defences can be built along rivers (e.g. levees) and coasts (e.g. sea walls)
What is the aim when protecting an area from the effects of a tropical storm?
To reduce number of buildings destroyed, so fewer people will be killed, injured, made homeless and made unemployed
