Hazardous Earth

• What are the three types of circulation cells?

  Polar cells,Ferrel cells and Hadley cells

  
• Where does the Earth receive all its heat from radiation?

  From the sun
• Why does the Equator receives the most concentrated radiation?


  The Sun's rays hit the surface almost at a right angle.
• What happens as the ground heats up?

  It warms the air above it,so warm air rises and transfers heat to the atmosphere.Later this air cools,becomes denser and sinks towards Earth.
• What is the distribution of solar radiation across the Earth's surface on 21st March and 23rd September?

  The earth is roughly spherical,so more solar radiation is receive at the equator ,the hottest part of the Earth's surface that at the poles where it is colder.

  
• Where does the radiation hit the surface near the poles?

  They reach the surface at a lower angle so the same amount of radiation heats a much larger surface area.
• Near the poles,what does the angle of the Sun's rays mean?

  It means they pass through a thicker atmosphere,which absorbs more energy than near the equator.
• How are winds caused?

  When air moves from high to low pressure.
• Why doesn't the air flow in a straight line?

  because the Earth rotates.
• Describe what is the Coriolis effect?


  As the air moves above the surface of the Earth,underneath it the palnet continues to rotate,so winds actually follow a curved path

  
• What is the definition of Coriolis effect?


  The deflection of air movement by the Earth's rotation.
• In the northern hemisphere,which direction is the wind deflected?

  to the right
• In the Southern Hemisphere.which direction is the wind deflected?

  to the left
• This picture shows the resulting pattern of global winds,blowing from high pressure belts to low pressure belts.

  
• What are jet streams?

  A fast moving current of air in the upper atmosphere.
• What are jet streams 2?


  Jet streams are continous wind and they happen when cold air meets warm air
• Where are jet streams mostly formed?

  At the boundaries of the main circulation cells(e.g. at the polar cell and a Ferrel cell) where there is a significant temperature difference.
• The northern Polar jet stream


  cold air meets warm air

  
• these streams can affect the movemnet of other weather systems and..

  can therefore change the weather for different areas.
• Identify two ways in which heat at the Equator can be re-distributed around the world?

  Atmospheric and oceanic circulation
• How effective are oceans in redistributing heat around the Earth?

  just as effective as air is
• Why does a location's proximity to the oceans can have a large impact on its climate?

  because water can hold heat for a long time.
• How are surface ocean currents driven?

  By the movement of water accross the top of the water.
• How are deep ocean currents driven?

  by water sinking and rising water because of temperature changes.
• Explain how ocean currents can affect the climate of an area.


  Surface currents move warm water from the tropics north and south towards the poles.These currents transfer hear away from the tropics.As the water reaches the poles,it cools significantly and sinks towards the depths of the ocean.These deep ocean currents eventually return to the surafce and flow back towards the tropics and the cycle starts over again.

  
• How can the Coriolis effect and jet stream impact on the weather of an area?


  The coriolis effect is due to the earth spinning on a tilt.In the northern hemisphere,winds blow to the north and in the sourthern hemisphere,wind blow to the south.This results in different weather pattens.Jet streams are continous wind and happen when cold air meets warm air
• Describe what is meant by atmospheric pressure


  Atmospheric pressure is the 'weight' of the air and the force this exerts on the ground.Pressure has a big impact on thee climatic features of an area.
• Describe atmospheric pressures


  As the air continues to rise away from Earth's surface,the heating effect from the warm ground is reduced and the air begins to cool.Cooler air has less energy and so it begins to sink back towards the Earth.

  
• Low atmospheric pressure - The warm air rises and it rains

  High atmospheric pressure- The 'weight' of the sinking air exerts more pressure

  
• What does arid mean?


  not a lot of rainfall -less than 250mm in a year

  
• Where are arid areas?

  between hadley and ferrel cells
• What does it mean if there are areas of high pressure?

  It means there is not a lot of rain
• Where do the hadley and the ferrel cells meet?

  Around 30 degrees north and south of the equator
• What do areas with regular low pressure experience?

  High rainfall
• What is caused when air sinks it becomes denser and its pressure increases?

  It causes it to warm up and dry out.
• What does increasing the pressure stop?

  It stops any remaining moisture in the air from condensing so no clouds form.
• Dry air and dry clouds mean..

  no rain
• What is the reasons arid areas receive low average rainfall?


  1) The Sun's radiation is intense here and the clear skies mean that daytime temperatures are very high.

  
  

  2)When sinking dry air reaches the surface it blows outwards.Over land this can block moist winds from blowing inland from the sea to bring rain.
• climate graph

  
• Describe what inter-tropical convergence zone is.


  This happens between two hadley cells,where warm tropical air flows towards the Equator from north and south.Here the Sun's radiation is most intense and high temperature cause the tropical air to rise rapidly.As this air rises is expands and becomes less dense,causing low pressure.Rising moisture-heavy air causes thunderclouds(cumulonimbus clouds) to form.It means rain everyday.