1) Hazardous Earth Flashcards
What are winds?
Movements of air on a large scale
What causes winds?
Differences in air pressure
What causes differences in air pressure?
Different temperatures causing movement
How does air pressure affect winds?
WInds mmove from high pressure areas to lower pressure areas
What are the 3 atmospheric circulation cells called?
Hadley
Ferrel
Polar
What does cool sinking air form?
High pressure belts of wind
What does warm rising air form?
Low pressure belts on wind
How many global atmospheric circulation cells do the North and Suth poles have each?
3
What are westerlies?
Surface winds that blow from 30 degrees to the poles
What direction do westerlies blow in the southern hemisphere?
North-west to south-east
What direction do westerlies blow in the northern hemisphere?
South-west to north-west
What are trade winds?
Surface winds that blow from 30 degrees to the equator
What direction do trade winds blow in the southern hemisphere?
South-east to north-west
What direction do trade winds blow in the northern hemisphere?
North-east to south-west
What does the global atmospheric circulation model describe?
How air circulates between low and high pressure belts
What happens to air at 30 degrees?
Cool air falls
High-pressur ebelt with minimal rainfall and no clouds
What happens to air at 60 degrees?
Cold air blown from poles meets warm surface winds
RIses and forms a low pressure belt
Air splits, some to equator and some to poles
What happens to air at the poles?
Cool air sinks
High pressure belt
Moves back towards equator as surface winds
What do ocean currents transfer?
Heat from warmer to cooler areas
What do surface currents do?
Transfer heat from the equator to cooler regions
What are deep ocean currents caused by?
Differences in water density
What is thermohaline circulation?
1) Water freezing at the poles causes the surrounding water to become saltier and denser
2) Sinking of dense water lets warm water flow near the surface which cools and sinks creating a cycle
What are surface currents caused by?
Winds
What determines arid and dry regions?
Pressure belts
What causes tropical climate zones?
Air rising where Hadley cells meet creating low pressure belt
What causes arid climate zones?
Air sinking where Ferrel and Hadley cells meet creating high pressure belt
What is the name of the circulation system that causes deep ocean currents?
Thermohaline circulation
At what latitude does cool air sink?
30 degrees
What climate period are we currently in?
Quaternary period
Which period came before the quaternary period?
Neogene
How long do glacial periods last for?
Roughly 100,000 years
How much do scientists predict the earth’s temperature to have risen by by 2100?
4 degrees since 1880
When does the greenhouse effect happen?
When greenhouse gases absorb heat that has been reflected off the Earth and re-radiate this heat back towards Earth
What 4 methods are evidence for climate change?
Tree rings
Ice cores
Temperature records
Pollen analysis
How does pollen analysis provide evidence for climate change?
Plant pollen can be preserved in sediment
Comapring pollen from sediment to current plant pollen can indicate differences
How do temperature records show climate change?
Temperatures have been recorded since 1850
Very reliable but not very old
How do ice cores show climate change?
Each year a new layer of ice freezes on top of an ice sheet
Examining gases in each layer shows what temperatrue was like hundreds of years ago
How do tree rings show climate change?
Every year a new ring forms
Rings are thicker in good conditions for growth (wet, warm)
Gives data for up to the last 10,000 years
What are natural causes of climate change?
Oribtal changes
Asteroid collisions
Volcanic activity
Solar output variation
What is the Milankovitch cycle?
Earth’s orbit changes from circular to elliptical and back every 96,000 years
How do oribtal changes cause climate change?
When the Earth is closer to the sun, more of the sun’s radiation will warm the Earth
How do asteroid collisions cause climate change?
Collisions with Earth cause last amounts of dust particles to reduce the amount of sunlight reaaching Earth
How does volcanic activity cause climate change?
Eruptions can release carbon dioxide
Particles can reflect the sun’s radiation
What is a volcanic winter?
When particles from volacnic eruptions prevent sunlight from warming the earth
What human factors cause climate change? (4)
Industry
Energy
Transport
Farming
How does farming cause climate change?
Livestock produce methane during digestion
How does transport cause climate change?
Most modern cars run on fossil fuels
How does energy cause climate change?
Fossil fuels are burnt releasing carbon dioxide
How does industry cause climate change?
Cement production produces greenhouse gases
Decay of industrial waste produces methane
What evidence is there that human activity is causing climate change? (4)
Declining arctic ice
Global temperature rise
Sea level rise and warming oceans
Increased extreme weather events
What are effects of climate change on the environment? (5)
Changing precipitation patterns Changing distribution of species Sea surface temperature increase Reduction of biodiversity Melting ice
What are rising sea surface temperatures casuing to happen?
Bleaching of corals
More severe cyclones
What negative effects does a changing distribution of species have on the UK?
Malaria and exotic diseases will become present
What are effects of climate change on people? (5)
More deaths due to heat Lower crop yields Problems with water availability Loss of coastal areas More extreme weather events