Chapter 5 part 3: El Niño-Southern Oscillation• Warming of waters in the eastern equatorial Pacific
– Equatorial region off South America coast• El Niño – “the boy” reference to the Christ Child• Associated with numerous changes in weather patterns
worldwide• Typically occurs on time scales of 3 to 7 years for about 18
months
1Figure 5-37
Circulation patterns—Walker circulation
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Figure 5-38
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Figure 5-39: Bulge of warm water slowly moving across the equatorial Pacific Ocean.
• Patterns associated with El Niño
• ENSO—Southern oscillation
• La Niña—opposite of El Niño
• Causes of El Niño– Atmosphere changes first or
ocean changes first?– Weather effects
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Figure 5-40
Forecasting El Nino
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Figure 5-B: Buoy array.
Figure 5-C: Normal Conditions in tropical Pacific Ocean.
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Figure 5-D: El Nino Conditions in tropical Pacific Ocean.
Figure 5-E: La Nina Conditions in
tropical Pacific Ocean.
Summary:
•El Niño is a warming of eastern equatorial Pacific water and subsequent switching of the high and low air pressure patterns
•El Niño is associated with varied weather patterns in different locations globally 7
Cruise ship: Ocean Seeker (Ka’im-im-o-ana)