Geography

• Factors influencing temperature and rainfall


  • Distance from the equator
  • Distance from the sea
  • Ocean currents and winds
  • Mountains (relief)
  • Height above sea level (altitude)
• Distance from the equator


  • The sun shines more directly on the equator for more hours during the year than anywhere else
  • There is also a small area that is heated by the sun
  • Hot temperatures are found near the equator
  • When you move away from the equator towards the poles, less sun is received, and the heat received spreads over a wider area
  • Polar areas become cooler than tropical areas
• Equatorial areas are warmer


  • Heated and moisture-laden air rises and cools, forming clouds and rainfall
  • In polar areas air is colder and descends, creating cold weather conditions
• Distance from the sea


  • Sea temperature generally changes at a slower rate than land temperature
  • This leads to mild winters and cool summers in coastal areas
  • If the temperature over the land drops, the area near the sea will be kept warmer for longer hours than inland areas
  • Inland temperatures are generally low (cold) in winter and high (hot) in summers
• The further moisture-laden air blows from the sea


  • The more moisture it loses and the drier it becomes
  • Hinterland areas generally receive less rain than coastal areas
• Height above sea level


  • The higher you go, the lower the temperature or the colder it becomes
  • Air temperature depends on air density
  • Air at higher altitudes is less dense and colder
  • Air at lower altitudes is more dense and warmer
  • For every 1000 m increase in altitude, the temperature drops by 6.5 °C
  • Mountainous areas receive more rainfall than flat and lower areas
• Mount Everest is the world's highest mountain at 8848 m above sea level and is covered with ice
• Ocean currents


  Generally driven by prevailing winds that blow over them
• Currents from equatorial and tropical regions

  Are warmer and raise the temperatures of areas along the east coasts of continents
• Currents from polar regions


  Are cold and lower the temperatures of areas along the west coasts of continents
• Areas along the east coasts of continents


  Generally receive more rainfall than areas along the west coasts of continents
• Aspect


  The direction that the slope is facing
• Mountain slopes facing the sun

  Generally warmer than those facing away from the sun
• In the Southern Hemisphere, mountain slopes facing north or towards the equator

  Warmer (higher temperature) than south-facing slopes
• In the Northern Hemisphere, south-facing slopes

  Warmer (higher temperature) than north-facing slopes
• Warmer slopes (high temperature)


  Receive more rainfall than leeward slopes (slopes facing away from the sun)
• Earth's rotation


  Spins or rotates on its axis
• Time for one complete rotation

  24 hours
• Earth's axis


  Inclined/tilted at an angle of 23.45 degrees from the perpendicular (vertical axis) to the plane of the ecliptic
• Direction of Earth's rotation

  West to east
• Raising a rotating globe (a model of the Earth) above our heads

  • Clockwise rotation of the Earth from a view of the South Pole
• Lowering the rotating globe


  • Anti-clockwise rotation
• Rotating movement of the Earth


  Results in daily cycles of day and night
• One half of the Earth faces the sun


  Experiences day
• The other half of the Earth is faced away from the sun


  Experiences night
• The Earth is constantly rotating on its axis
• We experience different times of day and night
• It takes 12 hours from midnight to midday and 12 hours from midday back to midnight
• Places at different parts of the equator

  • Celebes
  • Lake Victoria
• Earth's axis


  Imaginary line that extends from the North Pole to the South Pole
• Earth's axis


  • Not positioned at a right angle (90 degrees) to the sun
  • Tilted over at an angle of 23.5 degrees to the vertical
• Earth's tilted axis


  Results in the different seasons we experience
• Equinox


  Positions of the Earth around the sun when the Northern and Southern Hemispheres are positioned at an equal distance to the sun
• Equinox


  Sun's rays strike the equator directly, at 90 degrees
• Autumn equinox in Northern Hemisphere, spring equinox in Southern Hemisphere

  Usually 21 September
• Solstice


  Position when the Southern Hemisphere is tilted more closely towards the sun than the Northern Hemisphere
• Summer solstice


  Sun's rays strike the Tropic of Capricorn directly at 90 degrees
• Summer solstice


  Southern Hemisphere experiences summer, Northern Hemisphere experiences winter
• Summer solstice


  Position when the Northern Hemisphere is tilted more closely towards the sun than the Southern Hemisphere
• Summer solstice


  Sun's rays strike the Tropic of Cancer directly at 90 degrees