Air Masses, Fronts And Depressions Flashcards
What are the 5 air masses in the UK?
Tropical continental Tropical maritime Polar continental Polar maritime Arctic maritime
What are air masses?
Large bodies of air that adopt the characteristics of the area of origin, bringing weather with them but also can create weather
What kind of weather do the tropical air masses bring?
Warm/very hot
What kind of weather do maritime air masses bring?
Wet weather
What kind of weather do continental air masses bring?
Dry weather
What kind of weather do polar and arctic air masses bring?
Cold/very cold
What are fronts?
Where air masses meet each other, they interact and react to each other and create weather
What are the 2 types of fronts?
Warm front
Cold front
What is an anticyclone?
A large mass of subsidising air which produces high pressure at the earth’s surface
What are the two types of anticyclones?
Cold and warm
What descending air mass does a cold anticyclone form from?
Either polar continental or arctic maritime
What are blocking anticyclones?
A large mass of air of high pressure that becomes stationary leading to periods of either intense cold (winter) or heat waves (summer)
What weather conditions does a cold anticyclone bring?
Extremely cold conditions
Days of continuous frost and freezing temps
Ice
Winter fog
What weather conditions can a summer warm cyclone bring?
Drought
Low level ozone
Thunderstorms
What is absolute drought?
Period of 15 consecutive days with less than 0.2mm rainfall
What is partial drought?
29 days with average daily rainfall not exceeding 0.2mm
What year was the European heat wave and was it a result of an anticyclone or a depression?
Early July - late sept 2003
Anticyclone
What were some short term responses to the European heat wave?
Hosepipe ban
Stay indoors
Emergency food supplies
What was a key long term response to the European heat wave?
Increasing water and electricity supply to meet the demand
What were some positive economic impacts of the European heat wave?
Rise in tourism
Benefitted retail
What were some negative socio-economic impacts of the European heat wave?
Cost of people taking days off - £7.5-10 million a day
Transport disruption - roads melted, London Underground reached 37 degrees
August death rate 15,000 more than expected
What was a negative environmental impact of the European heat wave ?
Increase in low level ozone
When was the UK Great Storm?
15th-16th October 1987
The Great Storm: what were reasons for vulnerability?
- the met office failed to predict the weather front = public weren’t aware of hazards
The Great Storm: what were some socio-economic impacts?
Cost: $1.4 billion
18 deaths
thousands of homes without power, not fully restored for two weeks
£860 million insurance claims
The Great Storm: what were some environmental impacts?
15 million trees lost
wild boar escaped from enclosures and have established populations
The Great Storm: what were some responses?
- greater observational coverage of the atmosphere by increasing quantity of satellites, aircraft and ship observation
- reform of the weather warning process
When and where was the big freeze?
UK and Ireland
December 2009 - Feb 2010
What were some physical causes of the big freeze?
Polar continental air mass brought high pressure and very low temps
air mass came over scandinavia
high pressure brought clouds = precipitation as snow
The Big Freeze: What were some reasons for vulnerability?
- unprepared with emergency services slow to respond
- little could be done to prevent
- electricity and heating prices very high = vulnerable
- heavy reliance on transport infrastructure
The Big Freeze: what were some socio-economic impacts?
school closure
death and injury - road accidents
£1.2 billion a day lost from infrastructural disfunction
The Big Freeze: what were some environmental impacts?
food for animals and wildlife short
The Big Freeze: what were some short term responses?
gritting and emergency services response improvements
The Big Freeze: what are some long term impacts?
improve supply of salt
When was the Mali drought?
February - August 2010
Mali Drought: what were some socio-economic impacts?
- inadequate water supplies
- farmers unable to grow crops = residents reliant on expensive food imports - can’t afford
Mali Drought: what are some environmental impacts
- desertification
- wildlife struggling
- soils too dry to grow certain crops
When was hurricane Katrina?
August 2005
Hurricane Katrina: where did it hit?
New Orleans
Katrina: what windspeeds and category hurricane was it?
Cat 4
windspeeds reaching 127mph
Katrina: what were some physical factors influencing vulnerability?
- large amounts of NO was beneath sea level
- surrounded by water, mouth of mississippi -low-lying delta region
- limited natural protection
Katrina: what were some human factors influencing the vulnerability?
- rely on levees to protect city - only able to withstand cat 3
- poorly maintained - high population density
- 11-12 million live in coastal areas
Katrina: what were some socio-economic issues?
- 1,500 deaths
- $300 billion damage
- 80% under 6m of water
- over a million evacuated
- trade badly effected & unemployment
Katrina: what were some environmental impacts?
- 20% of wetland lost = breeding affected
- 24.6 million litres of oil pumped into lake
- 5,300km2 of woodland and forest destroyed
When and where was Cyclone Nargis?
May 2008, Burma
Cyclone Nargis: what were some physical factors influencing the severity?
- low-lying delta region with a large coastline
- lack of vegetation/defences
- weak cat.4
- lack of accessibility due to location of airport
Cyclone Nargis: what are some human factors influencing the severity of the cyclone?
- poor governance - military takeover since 1962 = prevented help from international aid organisation for weeks, expected people to recover alone
- concentrated population in rural areas with high reliance on agriculture - 68% rural; 32% urban
- poor, with low standard of living: phone lines/100 people = 0.9; internet users/100 people = 0.1
Cyclone Nargis: What were some short term impacts?
winds reached 165mph - collapsed buildings = death and injury
600-700mm rainfall = flooding; disease; water pollution; crops submerged
storm surge = 3.5m
140,000 deaths
Cyclone Nargis: what were some long term impacts?
- $10 billion damage
- 2 million homeless
- 200,000 people without water, a year later
- paddy fields and aquifers still contaminated with salt water
- no way of making a living; food prices inflated
