Lesson 8: Circulation of the Atmosphere

Introduction to Atmospheric Circulation

• Overview of how the atmosphere interacts with the ocean.
• Importance of understanding atmosphere dynamics for marine scientists.

Key Concepts

Air Density and Temperature

• Density of Air:
  • Warm air is less dense due to the ability to hold more water vapor, leading to rising air.
  • Cool air is denser, holds less water vapor, and tends to sink.
• Effects of Rising and Sinking Air:
  • As warm air rises, it expands and cools down.
  • Sinking cool air compresses and warms up.

Movement of Heat

• Water vapor in the atmosphere holds and distributes heat.
• Heat transfer from the equator to the poles helps maintain global temperatures.
  • Prevents extremes: Keeps the equator from overheating and the poles from becoming too cold.

Coriolis Effect

• Explanation of how air movement curves due to the Earth's rotation, contributing to wind patterns.
• This effect is crucial for understanding global wind systems.

Atmospheric Circulation Cells

• Types of Cells:
  • Hadley Cells: Found near the equator; responsible for tropical climates.
  • Ferrel Cells: Located in mid-latitude regions; influence temperate climates.
  • Polar Cells: Found at the poles; drive polar climates.
• Intertropical Convergence Zone (ITCZ):
  • Formed where two Hadley cells meet, often resulting in heavy rainfall and storms.
  • Important for understanding monsoons and their global significance.

Effects on Local Weather

• Sea Breezes:
  • Result from the differential heating of land and water; occurs during the day.
• Land Breezes:
  • Occur at night; land cools quicker than water, reversing the air flow.

Hurricanes and Tropical Cyclones

• Overview of hurricane formation:
  • Powered by warm ocean water and atmospheric conditions.
• Discussion of the destructive potential of hurricanes:
  • Impact on coastlines and communities.

Study Tips

• Keep the Lesson 8 guiding questions handy as a study guide while reading.
• This lesson concludes Unit 2; complete the Unit 2 writing assignment by the due date.
• Prepare for the Unit 2 exam, which will cover lessons five through eight.