High pressure, heatwaves, & drought California, Variations in weather and climate in the UK. Flashcards
What do we mean by the word heatwave?
An extended period of hot weather relative to the expected conditions at that time of year.
What do we mean by the word drought?
A lack of precipitation in an area for a long period of time, often several months or years.
What is high pressure?
When cool air sinks.
Droughts develop slowly and are the result of what 3 things?
- A lack of rainfall,
- An environment that is poor at storing and retaining water,
- Hot weather which increases evaporation of water.
What caused the drought in California?
- 3 Years of significantly less rainfall,
- Lower winter rainfall due to the position of the jet stream (strong ribbon of wind that circles the globe they seperate cold polar air masses to the north and the warmer tropical air masses to the south),
- Dry air to the west of California that didn’t move or break up.
- Low air pressure and cold air from Canada was dragged down into the central and eastern areas of the USA missing California.
What were the social, environmental and economic impacts of the drought in California?
- 17,000 agricultural (farming) jobs were lost,
- Crop failure therefore food prices rose by 6%,
- Salmon and Trout died as the water had less oxygen in it due to the heat and falling levels of water,
- Most (HEP) Hydroelectric Power dams stopped producing electricity,
- groundwater supplies were not recharged,
- Wildfires 36% increase.
How did California respond to the drought?
- Water restrictions (no watering of gardens and washing cars),
- Low water technologies,
- Reduction in amount of electricity produced via HEP,
- Investment in desalination plants that remove salt from seawater,
- Farmers began to grow crops that do not need so much water.
What does the word precipitation mean?
Any form of water falling from the sky.
What type of climate does the UK have?
Temperate Maritime Climate.
What are the characteristics of the climate type the UK has?
- Absence of extreme climate conditions,
- Mild winter temperatures,
- Warm summers,
- Frequent but not extreme rainfall.
The prevailing wind direction in the UK is from the A) South East B) South West C) North East D) North West
South-West.
What four factors affect the climate in the UK?
- Latitude; The north of the UK has cooler temperatures than the south.
- Altitude; Mountain areas have colder temperatures they decrease 1 degrees C for every 200m of elevation.
- Aspect; South facing slopes are warmer.
- Ocean currents; The north atlantic drift brings warmer water to the UK’s shores and keeps the climate mild in winter and cool in summer.
What do we mean by maritime air masses?
Air masses that have come across the sea.
What do we mean by continental air masses?
They have come across land (continent).
Polar maritime air mass comes from the North West of the UK what weather does it bring?
Cool and showery (To the UK from Iceland).
