Southern Oscillation Cheat Sheet

Key Definitions

• Southern Oscillation (SO): A periodic fluctuation in sea surface pressure and winds over the tropical Pacific.

• El Niño: A warm phase of SO, characterized by increased sea surface temperatures.

• La Niña: A cool phase of SO, characterized by decreased sea surface temperatures.

Important Concepts

Oscillation Phases

• Normal Conditions: Trade winds blow from East to West; warm water accumulates in the Western Pacific.

• El Niño Conditions: Weakening of trade winds; warm water shifts towards the Eastern Pacific.

• La Niña Conditions: Strengthening of trade winds; cooler water in the Eastern Pacific.

Impacts

• Affects global weather patterns, including rainfall and temperature variations.

• Influences monsoon patterns in India, droughts in Australia, and hurricanes in the Atlantic.

Key Formulas

• P1: Pressure at Tahiti

• P2: Pressure at Darwin, Australia

Common Mistakes to Avoid

Common Mistake: Confusing El Niño with La Niña; remember El Niño is warm, La Niña is cool.

Memory Tricks

Tip: "E-L-N" —

- E for El Niño (warm)

- L for La Niña (cool)

- N for Normal conditions (trade winds)

Key Diagrams

   Normal        El Niño       La Niña
   Conditions    Conditions     Conditions
      |              |              |
      |              |              |
      V              V              V
   [Warm Water]   [Warm Water]   [Cold Water]
     <----          <----          ---->
   [Cool Water]   [Cool Water]   [Warm Water]