Global Atmospheric Circulation

• What is the atmosphere?

  The envelope of gases surrounding Earth
• What does climate refer to?

  The average weather over time
• What is atmospheric circulation?

  The large-scale movement of air distributing heat
• What do latitude lines indicate?

  How far north or south of the equator
• How do global temperatures vary?

  Different parts of Earth heat up differently
• What is the main source of heat for Earth?

  The sun is the main source of heat
• How does the curvature of the Earth affect radiation?

  It causes uneven distribution of solar radiation
• What happens to solar radiation at higher latitudes?

  It is spread over a larger surface area
• Why do polar regions not see daylight during winter?

  Due to Earth's tilt affecting sunlight exposure
• What is the relationship between air pressure and weather?

  High pressure brings calm, clear weather
• Where is pressure highest on Earth?

  At sea level
• What happens to air pressure with altitude?

  Pressure decreases with altitude
• What type of weather is associated with low pressure?

  Cool, cloudy weather with precipitation
• What is the equator known for in terms of pressure?

  It is an area of low pressure
• How does land heat compared to sea?

  Land heats and cools quickly
• What happens to air above heated land?

  It expands and forms low pressure
• How does sea temperature affect air pressure?

  Sea takes longer to heat and cool
• What do ocean currents do?

  Help redistribute warmth around the globe
• What causes ocean currents?

  Wind, salt concentration, and Earth's rotation
• What happens when cold, salty water sinks?

  It sets up a convection current
• What occurs when warm air rises at the equator?

  It cools and moisture condenses to form clouds
• What happens to air as it moves away from the equator?

  It cools and falls towards the surface
• What is the result of warm air rising in one area?

  Cool air sinks elsewhere, creating high pressure
• What does high pressure typically bring?

  Dry weather with no clouds
• How do surface winds behave in relation to pressure?

  They blow from high pressure to low pressure
• What is the effect of the Coriolis force on winds?

  It deflects winds due to Earth's rotation
• What type of weather is associated with high pressure systems?

  Fine, dry weather
• What are the main components of global atmospheric circulation?

  • Differences in air pressure caused by temperature
  • Winds move from high to low pressure
  • Three loops in each hemisphere: Hadley, Ferrel, Polar
• Describe the Hadley cell.

  • Warm air rises at the equator
  • Air cools and sinks at 30° N/S
  • Creates low pressure at the equator and high pressure at 30° N/S
• Describe the Ferrel cell.

  • Not driven by heat differences
  • Caused by friction with Hadley and Polar cells
  • Transfers heat energy between cells
• Describe the Polar cell.

  • Dense air sinks at the poles
  • Warm air rises at 60° N/S
  • Carries heat energy towards the equator
• How do ocean currents influence climate?

  • Transport warm water and precipitation to poles
  • Regulate global climate and temperatures
  • Prevent extreme regional temperatures
• What is the role of the Gulf Stream?

  • Carries warm water up the eastern US
  • Influences climate in Western Europe
  • Part of the North Atlantic current system
• What happens at 60° N/S in global circulation?

  • Cold polar air mixes with warmer air
  • Creates a low-pressure belt
  • Causes rising air and precipitation
• What is the significance of trade winds?

  • Blow towards the equator
  • Move from SE in southern hemisphere
  • Move from NE in northern hemisphere
• How does the Coriolis effect influence wind patterns?

  • Winds in the north deflect to the right
  • Winds in the south deflect to the left
  • Affects global wind circulation
• What is the significance of westerlies?

  • Blow towards the poles
  • Move from NW in southern hemisphere
  • Move from SW in northern hemisphere
• What are the characteristics of low-pressure systems?

  • Associated with cloudy and rainy weather
  • Air rises, leading to precipitation
  • Often found at the equator
• What are the characteristics of high-pressure systems?

  • Associated with fine, dry weather
  • Air sinks, leading to clear skies
  • Often found at 30° N/S
• How does heat move around the planet?

  • Through air movement caused by pressure differences
  • Via ocean currents redistributing warmth
  • Influences global climate patterns