weather hazards Flashcards
what are global atmospheric circulation cells?
global atmospheric circulation cells are made up of
-cool sinking air (high pressure belts of wind)
-warm rising air (low pressure belts of wind)
how many cells does the Northern and Southern hemisphere have? what are they called?
northern and southern have 3 cells each
they are called Hadley, Ferrel and Polar
what are the westerlies?
surface winds that blow from 30 degrees north towards the north pole
or from 30 degrees south to the south pole
what are the trade winds?
surface winds that blow from 30 degrees north or south back towards the equator
trade winds meet at the equator where they are heated and the cycle begins again
what type of weather hazards are common in the Uk?
-hail and thunderstorms
-snow and ice
-rain
-heat waves
-drought
-wind
why is wind a hazard in the UK
railway lines and airports sometimes have to shut and coastal/upland regions suffer
why are heatwaves a hazard in the UK
humans and animals can suffer heat exhaustion and transport can be disrupted (rails buckle and tarmac melts)
How can we describe tropical storms?
Very intense, low-pressure weather systems forming above tropical oceans and gave extreme rain and winds
What does the water temperature have to be for tropical storms to form?
They form over water that is 26.5 degrees or warmer
Why do tropical storms move west?
Near the equator, surface winds are mainly trade winds moving east
Why do tropical storms spin?
Because of the earths rotation
List the features of the tropical storms
-circular shape
-hundreds of kilometres wide
-last one-two weeks
-spin direction depends on the hemisphere
What is the structure of a tropical storm?
Centre = eye of the storm
Around the centre = eyewall made of cumulonimbus clouds
What are conditions like in the eye of a storm?
No rain and low pressure and high temperature
How big can the eye of the storm be?
Up to 50km wide
What are conditions like in the eyewall
Winds are strong and there is lots of rain
Describe the distribution/changing distribution of tropical storms?
Currently they mostly happen near the equator where the sea temperature is above 26.5 degrees
Becuase of climate change, more of the sea will be warmer so they will happen more in more places
They’ll also become more intense becuase the sea will be hotter
which effect linked to the Earth’s rotation causes storms to spin and move west?
The Coriolis Effect
list the primary effects of tropical storms
-damage to infrastructure like transport and bridges
-flights and trains cancelled becuase of wind
-flying debris can hurt people
-electric cables and pylons damaged
-rivers and coastal towns flooded - sewage could overflow and mix with water supplies
list the secondary effects of a tropical storm
-floods can damage people’s houses causing homelessness
-if water/electric is cut off people can be stranded from basic health requirements
-people may not be able to get to work and make money
-damage to crops and livestock and blocked supply lines contributing to food shortages
list the immidiate responses to tropical storms
-evacuation
-people left stranded by flooding etc rescued by emergency services
-tents, food, water can be provided
-anybody killed to be found and buried to stop disease
-govornment/nongov aid to be sent quickly
list some long term responses to tropical storms
-repair peoples flooded homes and infrastrucure
-encourage economic recovery eg tax relief
-improve early prediction and make buildings safer
how can scientists predict storms?
-they can monitor using satilites and radars
-meterorologists build models to forecast weather however its not always acurate
how can buildings be protected by storms?
-planning regulations can ensure buildings are built safely
-stilts used to help stop flooding
-reinforced concrete
-flood defeces
how high were the wind speeds in typhoon haiyan?
275 km/hr
how high was the storm surge in typhoon haiyan?
5m
what were the primary effects of typhoon haiyan?
-6,300 people killed
-damage to 40,000 homes
-90% of the city of Tacloban was destroyed
what were the secondary effects of typhoon haiyan?
-roads were blocked by landslides caused by flooding
-disease outbreaks were caused by lack of clean water/sanitation
what were the immidiate responses to typhoon haiyan?
-over $1.5 billion of foreign aid pledged
-1,200 evacuation centres set up
-250,000 litres of water distributed in two weeks
-1 million packs of food
what were the long term responses to typhoon haiyan?
-Oxfam replaced fishing boats
-homes were rebuilt in safer areas - Build Back Better launched in 2014 by government (upgraded damaged buildings and a no-build zone)
where did typhoon haiyan form?
over warm tropical waters of the Pacific Ocean
what category storm was typhoon haiyan?
category 5 ‘super’ typhoon
what country and what island did typhoon haiyan affect?
Philippines, Island of Leyte
whats the name of the model that describes how air circulates at different latitudes?
global atmospheric circulation model
When was the Boscastle flood?
16 August 2004
What happened in the Boscastle flood?
Heavy rainfall caused two nearby rivers to burst their banks
What were 4 causes of the Boscastle flood?
-heavy rainfall (75mm in 2 hrs)
-harbour wall creates a bottleneck
-impermeable shale rock
-impermeable surfaces in the village
What were the responses to the Boscastle flood?
-natural wetland area and salmon spawning grounds created
-rebuilt car park with permeablesurface
-deepened and widened river to increase channel capacity
What were the effects of the Boscastle flood?
-50 cars destroyed
-80 houses destroyed
-disruption to local businesses
-habitats lost
-£4m in insurance claims
