A: Weather Hazards Flashcards
1
Q
What does air circulate between?
A
High and low pressure belts
2
Q
What are winds?
A
Large scale movements of air cause by differences in air pressure
3
Q
Differences in air pressure are caused by
A
Differences in temperature between the equator and the poles.
4
Q
Where do wines move from
A
Ares of high pressure to areas of low pressure
5
Q
What are winds part of
A
Global atmospheric circulation loops (or cells) these loops have warm rising are which creates a low pressure belt and cool falling air which creates s Hugh pressure belt
6
Q
What happens at the equator
A
The sun warms the earth which transfers heat above causing it to rise
7
Q
What happens when heat rises
A
Creates a low pressure belt with rising air, clouds and rain
As the air rises it cools and moves out to 30 degree north and south of equator
8
Q
What happens at 30 degree north and south of equator
A
The cool air sinks, creating a high pressure belt with cloudless skies and very low rainfall
9
Q
The cool air reaches the ground surface and moves as surface winds either back to the equator or towards the poles :
A
- surface winds blowing towards the equator are called trade winds
- they blow from the SE in the Southern Hemisphere and from NE In the northern hemisphere. At the equator these trade winds meet and are heated by the sun. This causes them to rise and from clouds
- surface winds blowing towards the poles are called westerlies. They blow from the NWin the Southern Hemisphere and from the SE in the northern hemispheres
10
Q
60 degree north and south of the equator the warmer surface winds meet colder air from the poles. The warmer air..?
A
Is less dense than the cold air so it rises, creating low pressure
11
Q
What happens at the poles
A
Cool air sinks, creating High pressure. The High pressure is drawn back tiwRds the equator as surface winds
12
Q
Low latitudes have
A
Warm air because there closer to the equator and therefore the sun rays are direct and don’t have to travel far
13
Q
Hugh latitudes have
A
Cold air because there further away from the equator and the sun rays have to travel further
14
Q
What makes high pressure
A
Cool air sinks
Lots of air pushing on floor
15
Q
What makes low pressure
A
When warm air rises
Not much air pushing on floor
16
Q
What is in the tricellular model
A
Polar cell
Ferrel cell
Hadley cell
17
Q
Which way does the cells go in the tricellurlar model
A
Polar cell - anti
Ferrel cell - clockwise
Hadley cell - antic
18
Q
What conditions does high pressure cause
A
Bright conditions
19
Q
What conditions does low pressure cause
A
Rainy conditions
20
Q
Where’s polar cell
A
60 degree Uk
21
Q
Where’s ferrel cell
A
30 degree desert
22
Q
Where’s Hadley cell
A
Equator
23
Q
description of the atmospheric circulation
A
- basis of everyday weather
- sun provides all energy causing changes in weather
- sunlight hits equator directly
- lower angled more sunlight reflected
- 30% solar radiation reflected back in space
- greenhouse effects - without average temp -18degrees with 15degreez
- atmosphere hotter at ground
- warm air rises - expands and rises - convection
- cold air is heavier and sinks
- air cooks = high pressure when air sinks warm rises = low pressure
24
Q
When do tropical storms develop
A
When the sea temperature is 27 degree or higher and when the wind shear (the difference In wind speed) between higher and lower parts of the atmospher is low
25
How do tropical storms occur
Warm moist air rises and condensation occurs. This releases huge amounts of energy which make the storms powerful. The rising air creates an area of low pressure which increases surface wind
26
Where do tropical storms move towards
The west because of the easterly winds near the equator
27
What does the earths rotation do
Deflects the paths of the winds which cause the storms to spin
28
How does the storm get stronger
Due to energy from the warm water so wind speeds increase. They lose strength when they move over land or cooler water because the energy supply from the warm water is cut off
29
Where do most tropical storms occur
Between 5 degree and 30 degree north and South of the equator - any further from the equator the water isn’t warm enough, the majority of storms occur in the northern hemisphere (especially over the Pacific) in late summer and autumn, when s w temperatures are highest
30
Hurricane formation
Sun rays heat up water between tropics of cancer and Capricorn
Sea water between two tropics rises to 27 degrees Celsius
Evaporation occurs over 100s of square miles
Warm water vapour eises creating a large area of low pressure
Water vapour reaches the dew point
Water vapour condenses
Condensation occurs over 100s of square miles
A very large storm cloud is formed
The earths spin causes the storm cloud to roatat which in turn creates and ‘eye’
Once the storm cloud has an “eye” it is classed as a hurricane and continues to suck up water vapour
The hurricane hits land and can not suck up anymore water vapour and dies
31
Tropical storms are what in shape
Circular and hundreds of kilometres wide and usually last 7-14 days.
32
Which way do tropical storms spin in the northern hemisphere
Anitclockwise
33
Which way do tropical storms spin in the Southern Hemisphere
Clockwise
34
What’s the centre of the storm called and its features
The eye
Up to 50 Km across and is caused by descending air
Low pressure, light winds, no clouds, no rain and a high temperature in the eye
35
What is the eye of a storm surrounded by?
Eyewall
Spiralling rising air, very strong winds (around 160 km per hour)
Storm clouds
Torrential rain
Low temperature
36
What happens towards the edges of a storm?
The wind speed falls, the cloud become smaller and more scattered
The rain become less intense
Temperature increases
37
How might climate change affect tropical storms?
Global temperatures are expected to rise as a result of climate change. This means that more of the worlds oceans could be above 27degrees so more places in the world may experience tropical storms
Oceans will stay at 27degrees or higher for more of the year - Humber of tropical storms each year could in crease
High temeperature also means tropical storms will be stronger meaning they could cause more damage
38
Primary effect examples of tropical storms
Buildings and bridges destroyed
Rivers and coastal areas flooded
People drown or they’re injured or killed by debris that’s blow around
Roads railways ports and airports are damaged
Electricity cables are damaged cutting off supplies
Sewage overflows due to flooding the sewage often contaminated water supplies
39
Secdondary effect examples of tropical storms
People are left homeless which can cause 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 - diseases spread easier
Roads are blocked or destroyed so air and emergency vehicles can’t get through
Businesses are damaged or destroyed causing unemployement
There can be shortages of food if crops are damaged, livestock are killed or supply lines blocked
40
Immediate responses to tropical storms
Evacuate people before storm arrives
Rescue people who have been cut off by flooding and treat injured people
Set up temporary shelters for people who’s homes have been flooded or damaged
Provide temporary supplies of water, food, electricity, gas and communications systems if regular supplies have been damaged
Recover any dead bodies to prevent the 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 the storm to be shared
41
Long term responses to tropical storms
Repair homes or rehouse people who have been displaced due to damaged buildings
Repair or replace damaged infrastructure
Repair and improve flood defence systems eg levees and flood gates
Improve forecasting techniques to give people more warning in the future
Provide aid, grants or subsidies to residents to repair and strengthen homes
Promote economic recovery in the area and encourage people to return to the area
With tax breaks or other incentives
Improve building regulations so more buildings withstand hurricanes, or change planning rules so homes can’t be built in the most risky area
42
Case study of a tropical storm
Hurricane Katrina
43
Where did hurricane Katrina strike and when
Mississippi and Louisiana
(Alabama)
2005
44
Primary effects of hurricane Katrina
More than 1800 people were killed
300 000 houses were destroyed
Large areas were flooded, including 80% of New Orleans
3 million people were left without electricity
Some bridges collapsed
Coastal habitats were damaged
45
Secondary effects of hurricane Katrina
Hundreds of thousands of people were made homeless
230 000 jobs were lost from damaged businesses
Water supplies were polluted with sewage and chemicals
Total cost of the damage was estimate at $150 billion
46
Immediate responses to hurricane Katrina
70-80% of New Orlean residents were evacuated before the hurricane reached land
Mississippi and Louisiana declared states of emergency - they set up control centres and emergency shelters and stockpiled supplies
The coastguard, police, fire service and army rescued over 50 000 people
Charities collected donations and provided aid, including millions of hot meals
47
Long term responses to hurricane Katrina
The us government provided over 16 billion dollars for the rebuilding of homes, and provided funds to repair other essential infrastructure
The us army recommended that buildings are rebuilt on stilts or not rebuilt at all in very low lying areas
Repaired and improved flood defences for New Orleans coating 14.5 billion dollars were completed in 2013
48
How can predictions reduce effects of tropical 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 the storm
Predicting where and when a tropical storm is going to happen gives people time to evacuate and protect their homes and businesses eg by boarding up windows
49
How can planning reduce the effects of tropical storms
Future developments eg new houses can be planned to avoid the areas most at risk
Emergency services can train and prepare for disaster eg by practising rescuing people from flooded areas with helicopters this reduced the number of people killed
Governments can plan evacuation routes to get people away from storms quickly
50
How can protection reduce the effects of tropical storms
Buildings can be designed to withstand tropical storms eg by using reinforced concrete. Buildings can also be put on stilts so they’re safe from floodwater
Flood defences can be built along rivers (eg levees) and coasts (eg sea walls)
All these reduce the number of buildings destroyed, so fewer people will be killed, injured, made homeless and made unemployed
51
What weather hazards does the uk experience?
```
Rain
Wind
Snow and ice
Thunderstorms
Hailstorms
Heat waves
Drought
```
52
Describe rain as a uk weather hazard
Too much rain in a short time - flooding
Which can damage homes and possessions, disrupt transport networks and cause death by drowning
It can also force businesses to close and recovering from flooding can cost millions of pounds
53
Describe wind as a uk weather hazard
Strong winds (gales) can damage properties and cause disruption to transport
Uprooted trees and debris can injure or kill people
Forests can be damaged when trees are blown over
Winds are strongest in coastal areas of the uk, particularly the West coast, and in upland areas
54
Describe snow and ice as a weather hazard in uk
Snow and ice can cause injuries due to slippings and death due to the cold
Schools and businesses can be forced to shut and major disruption to road, rail and air travel can occur causing economic impacts
Cold snaps can damage crops and other plants
55
Describe thunderstorms in terms of uk hazards
Heavy rain lightning and sting winds occur in thunderstorms
They are most common in summer in the south and east of uk
Lightning can occasionally cause death and can cause fires that damage property or the environment
56
Describe hailstorms
Hailstorms make driving very dangerous
Damage property
Destroy crops
57
Describe heat waves
Sometime uk can have long periods of hot weather
Cause death from heat exhaustion or breathing difficulties as pollution builds up in the air
Disruption to transport from rails buckling or roads melting cause cause economic impacts - but the tourism industry may benefit from better weather
58
Describe droughts
Lack of precipitation
Water supplies can run low during a drought causing economic impacts such as crop failures, ruled to conserve water (like banning hosepipe use) have to be introduced
59
Where was there major flooding caused by storms and rainfall during the winter of 2013-14?
Somerset levels
60
What caused the Somerset levels flood
Hugh tide
Below sea level
Wettest January
Rivers hadn’t been dredged for 20 years (hadn’t removed silt and mud at bottom of the river)
61
Socail impacts of Somerset floods
Some parents couldn’t get children to school
600 homes affected
Some villages cut off
Major roads blocked
Power supplies were cut off
Residents evacuated to temporary accommodation for several months
Increased crime
62
Economic impacts of Somerset floods
Farm financial cost £10 million
Railway line was closed
1000 livestock were evacuated
Over 14000 acres of agricultural land was underwater
Roads were cut off so can’t get to work and no earning money
£75.6 million to repair
63
Environmental impacts of the Somerset floods
Farmers were prevented from grazing there animals
The flood water was heavily contaminated with sewage and other contaminants
Lots of stagnant water
Huge amounts of debris to be cleared
64
Where are the Somerset levels?
An area of coastal plain and wetland in central Somerset
South west of uk
650km^2
Flat land lying next to sea level
Mainly agricultural
Habitants for birds and plants
32 sites of special scientific interest
65
Immediate response to Somerset flooding
Rescue boats were deployed to help stranded people
Extra police patrols in response to reports of crime
Local community groups and volunteers have invaluable support
66
Long term repsonses toxsomerset flooding
20 year flood action plan has been drawn up
Uk government promised at least £30 million to help with repairs
Environment agency installed giant pumps from the Netherlands to lower water levels
Vulnerable communities will have flood defences
