topic 1 hazardous earth

• What is the main function of winds in global atmospheric circulation?

  Winds transfer heat from the equator to the poles
• Why does the Sun heat the Earth's surface unevenly?

  Solar radiation is greater at the equator than the poles
• What causes differences in air pressure?

  Differences in temperature cause differences in air pressure
• How do winds behave in relation to pressure areas?

  Winds blow from high pressure to low pressure
• What are the components of global atmospheric circulation loops?

  • Low pressure belt from rising air
  • High pressure belt from cool, sinking air
• How many cells are there in each hemisphere of global atmospheric circulation?

  Three cells
• What happens to air at the equator?

  Air rises, creating a low pressure belt
• What occurs when air rises at the equator?

  It cools and condenses, forming clouds and rain
• Where does cool, dry air move after rising at the equator?

  To 30° north and south of the equator
• What does the cool air create at 30° north and south of the equator?

  A high pressure belt with clear skies
• What are surface winds blowing towards the equator called?

  Trade winds
• From which directions do trade winds blow in the southern hemisphere?

  From the southeast
• What happens to trade winds at the equator?

  They meet and are heated by the sun
• What are surface winds blowing towards the poles called?

  Westerlies
• What occurs at 60° north and south of the equator?

  Warmer surface winds meet colder air
• What is created when warmer air is forced to rise at 60° latitude?

  Low pressure and frontal rain
• What happens to cool air at the poles?

  It sinks, creating high pressure
• How do ocean currents transfer heat energy?

  • Large scale movements of water
  • Transfer heat from warmer to cooler regions
• What causes surface ocean currents?

  Winds
• What is the Gulf Stream known for?

  Bringing warm water to Western Europe
• What drives deep ocean currents?

  Differences in water density
• What happens when water freezes at the poles?

  Surrounding water becomes saltier and denser
• What is thermohaline circulation?

  A cycle of cooling and sinking water
• What are the climate zones caused by global atmospheric circulation?

  • Arid (Dry)
  • Polar
  • Tropical
• What causes arid climate zones?

  High pressure prevents rainfall
• What characterizes polar climate zones?

  Low temperatures and very little rainfall
• What is typical of tropical climate zones?

  Hot temperatures and high rainfall
• What is climate change?

  A significant change in climate over time
• What is the Quaternary period?

  The most recent geological time period
• How has global temperature shifted during the Quaternary?

  Between cold glacial and warm interglacial periods
• When did the last glacial period end?

  Around 15,000 years ago
• What are the natural causes of climate change?

  1. Orbital changes
  2. Volcanic activity
  3. Solar output
  4. Asteroid collisions
• What are orbital changes?

  Variations in Earth's movement around the Sun
• What is the stretch in orbital changes?

  The path of Earth's orbit changes shape
• How often does the Earth's axis tilt change?

  About every 41,000 years
• What is wobble in orbital changes?

  The axis of Earth wobbles like a top
• How do orbital changes affect climate?

  They affect the amount of solar radiation received
• What is the impact of major volcanic eruptions?

  They can cool the Earth's surface temporarily
• What was the result of the Mount Tambora eruption?

  It caused the 'Year Without a Summer'
• How does solar output change?

  It changes in cycles of about 11 years