Hazardous Earth Flashcards
What are the 3 cells in the Global atmospheric Circulation
Hadley , Ferrel and Polar
Describe the Hadley Cell
Located nearest to the equator, it is where hot moist air rises moves to higher latitudes and sinks back down
Describe the Ferrel cell
Located at around 60° on either side of the equator, it is where cold air sinks, travels to travels to higher latitudes and rises along with the air travelling from the poles (Polar cell)
Describe the Polar cell
At 60°-90° north or south of the equator, cold air sinks and travels to the poles (90°), where it rises
What happens when air rises
The warmth of the Earth’s surface causes air tor ise, exerting less pressure on the ground forming
low pressure causing rainfall.
What happens when air sinks
The ‘weight’ of sinking air exerts more pressure
on the ground and an area of high pressure is
formed causing areas to become arid.
What are ocean currents
They are the predictable continuous movement of water in the ocean
What impact do Ocean currents have on the worlds climate system?
Ocean currents move around the world transferring energy to other regions. Ocean currents can transfer warmer water to colder regions and colder water to warmer regions
What are the Natural causes of Climate change
Asteroid Collisions
Variations in the Earths orbit around the sun
The effects of volcanic eruptions
Changes in the solar output of our sun
How do Asteroid collisions have an impact on Climate change?
If an asteroid is large enough millions of tonnes of ash and debris would be ejected into the atmosphere when it impacted the earth. This could block the sun, cooling temperatures
How does Orbital change have an impact on Climate change?
There are three main ways of this:
Eccentricity
Obliquity
Procession
What is Eccentricity and how does it affect the earths climate?
The Orbit of the earth around the Sun changes from a circle to a Oval
This affects how strong the suns rays are on the earth
What is Obliquity and how does it affect the earths climate?
Obliquity is the Tilt in the earths axis affects the contrast between summer and winter seasons
What is procession and how does it affect the earths climate?
Procession describes the Wobble in the earths axis , it affects the lengths of days.
How does solar output have an impact on Climate change?
There are variations in the amount of energy that the sun emits which are thought to have an effect on the earths climate
What is the sunspot cycle
an 11 year cycle where the amount of sunspots on the sun varies from a minimum to a maximum and then back to a minimum
How do volcanic eruptions have an impact on Climate change?
The ash and gas that is erupted into the atmosphere when there is a huge eruption can cause a cooling effect, by either blocking out the sun, or can emit sulfurous gases which react to form aerosols which reflect solar radiation.
What are the 3 pieces of evidence which show natural climate change
Tree rings
Ice cores
Historical sources
How are Ice cores used to show past climate change?
Ice cores have past layers of snow turned into ice which show gradual changes temperatures
Carbon dioxide air bubbles may be trapped in the ice cores which may also show past temperatures
How are tree rings used to show past climate change?
Each year trees gain another ring, scientists can use tree rings to work out past temperatures, for example if temperatures were more warmer the tree ring would be larger
How are Historical sources used to show past climate change?
Historical sources created by people can help understand climate before accurate measurements were recorded.
What Human activities cause the enhanced greenhouse effect
Burning Fossil fuels
Agriculture
Deforrestation
What are the consequences on people by the enhanced greenhouse effect
Increasing temperatures
Rising sea levels
damage to property
Crops dying
Give two reasons to why sea-levels increase
Glaciers melting
Thermal expansion ( the sea takes up more space when it is warm)
What are the Characteristics of a tropical cyclone
Strong winds
intense rainfall
Low pressure
Thunder and lightning
What is the Global distribution of tropical cyclones
-Tropical cyclones develop between 5-15° –
north or south of the equator in warm oceans
-Ocean temperatures must be 26-27°c and at least 50 m deep
-must be in areas with unstable air pressure
Why do tropical cyclones develop
Tropical storms usually form between 5° and 30° latitude. When the ocean surface waters reaches at least 27°C , the warm air above the water rises quickly, causing an area of very low pressure. As the air rises quickly more warm moist air is drawn upwards from above the ocean creating strong winds.
Why do tropical cyclones intensify
Increase in water temperatures