Understanding Global Wind Patterns

Nov 18, 2024

Lecture: Global Wind Patterns and Atmospheric Circulation

Key Concepts

  • Atmospheric Circulation: Refers to the large-scale movement of air, which helps distribute thermal energy (heat) across the surface of the Earth.
  • Global Wind Patterns: These are created by the uneven heating of the Earth’s surface and are influenced by the rotation of the Earth.

Main Atmospheric Cells

  • Hadley Cell:

    • Located between the equator and 30° latitude.
    • Warm air rises at the equator, creating low pressure.
    • The air cools and sinks at around 30° latitude, creating high pressure.
  • Ferrel Cell:

    • Located between 30° and 60° latitude.
    • Air moves poleward and eastward near the surface and equatorward and westward at higher altitudes.
  • Polar Cell:

    • Extends from 60° latitude to the poles.
    • Air at the poles is cold and dense, causing it to sink.
    • This air flows toward lower latitudes and rises around 60° latitude.

Trade Winds

  • Originate from the subtropical high-pressure belt and blow towards the low-pressure regions at the equator.
  • East-to-west direction in both hemispheres.

Westerlies

  • Winds blowing from the west to the east in the mid-latitudes between 30° and 60°.
  • Plays a crucial role in influencing weather patterns.

Polar Easterlies

  • Cold, dry prevailing winds that blow from the east to the west between 60° latitude and the poles.

The Coriolis Effect

  • Describes how the rotation of the Earth affects the direction of winds and ocean currents.
  • Causes moving air and water to turn and twist instead of moving in a straight line.

ITCZ (Intertropical Convergence Zone)

  • Area encircling the Earth near the equator where the northeast and southeast trade winds converge.
  • Characterized by convective activity which often results in thunderstorms and heavy rains.

Practical Implications

  • Understanding wind patterns is crucial for navigation, aviation, and predicting weather.
  • Influences climate by distributing heat and moisture around the Earth.

These notes provide a summary of key points related to global wind patterns and atmospheric circulation, suitable for study and review.