EQ1 Flashcards
(36 cards)
What are the names of the three cells at the equator?
Hadley
Ferrel
Polar
What does difference in temperature cause?
Differences in air pressure
What is insolation?
The solar radiation that reaches the earths surface.
This is greater at the equator than the po
How does heat get transferred away from the equator?
Winds blow from ateas of high pressure to areas of low pressure.
Winds are part of global atmospheric circulation loops called cells. These loops have warm rising air which creates a low pressure belt, and cool falling air which creates a high pressure belt.
What is the Coriolis force?
A strong Force created by the earths rotation
Describe what happens at a Hadley cell?
At the equator the Sun warms the Earth which transfers heat to the air above causing it to rise. This creates a low-pressure belt. As the air rises it calls and condenses forming clouds and rain
The cool dry air moves out to 30° north and south of the equator
What happens at a Ferrel Cell?
The cool air sinks creating a high-pressure about with cloudless skies and very low rainfall. The cool air reaches the ground surface and moves as surface winds either back to the equator or towards the poles.
Trade winds blow from the southEast in the southern hemisphere and from the north east in the northern hemisphere. At the equator the trade winds meet and are heated by the Sun. This causes them to rise and form clouds
What are tradewinds?
What are westerlies?
Trade winds are surface wind blowing towards the Equator
Westerlies are surface winds blowing towards the poles
What happens at a polar cell?
The warmer surface wins meet colder air from the polls. The warm air is less dense than the cold air so it forced to rise creating low-pressure and frontal rain (rain that forms where the warm and cold air masses meet.
Some of the air moves back towards the equator and the rest moves towards the poles. At the poles the cool air sinks creating high-pressure
What are ocean currents?
Ocean currents are large-scale movement of water that transfer heat energy from warmer to cooler regions
What are the two different type of water currents?
Deep ocean currents-these are driven by differences in water density
Surface currents-these are caused by wins that help transfer heat away from the equator
How do deep ocean currents form?
When water freezes at the polls, the surrounding water get saltier, increasing its density.
As it gets denser, it sinks, causing warmer water to flow into the surface creating a current
This warm water is cooled and sinks continuing the cycle
What is this cycle of cooling and sinking known as?
Thermohaline circulation
What do pressure belt caused by global atmospheric circulation cause?
They cause variations in climate
What is the most recent geological time period called?
Quaternary period
What was the period before the Quaternary period like e.g. the climate?
The earths climate was warmer and quite stable
What are some of the natural causes for climate change
Orbital changes
Volcanic activity
Solar output
Astroid collisions
How does orbital change cause climate change
Orbital changes are variations in the way the Earth moves around the sun
There are three cycles:
- stretch: the path of the earths orbit around the Sun changes from almost perfect circle to an eclipse and back again about every 96,000 years
- tilt:The earths axis is tilted at an angle as it orbits the sun. This tilt changes over a cycle of about 41,000 years
- wobble: the axis of the Earth wobbles like a spinning top on a cycle of about 22,000 years
The cycles affect the amount of solar radiation of the seeds. If the Earth receives more energy it gets warmer
How does volcanic activity cause climate change?
Major volcanic eruptions eject large quantities of material into the atmosphere
Some of these particles reflect the suns rays back out to space so the earths surface cools
Volcanic activity may cause short-term climate change
How does solar output cause climate change
The suns output of energy isn’t constant-it changes in short cycles of about 11 years and possibly also the longest cycles of several hundred years
Periods when solar output is reduced may cause the earths climate to become cooler
How do astroid collisions cause climate change?
Astroid hitting the Earth surface can throw up huge amounts of dust into the atmosphere
These particles prevent the suns energy from reaching the Earth surface of the global temperatures fall
Some scientists believe that an astroid collision caused a period of global calling around 12,000 years ago
How have scientists gathered evidence for natural climate change
Tree rings
Historical records
Ice cores
How are tree rings evidence for natural climate change
Most trees produce one ring within their trunks every year
The thickness of the rain depends on the climber when the ring was formed
when it’s warmer the tree rings are thicker
Scientist take cores through tree trunks then date on the train by counting them back from when the call was taken. By looking at the thickness of the rings they can see what the climate was like a
How are ice cores evidence for climate change
Ice sheets or made up of layers of ice. One layer is formed each year
Scientists drill into ice sheets to get long cores of ice
By analysing the gases e.g. carbon dioxide trapped in the layers of life they can tell what the temperature was each year
