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Climate Change. El-Nino Southern Oscillation (ENSO) Phenomena . El-Nino. El Nino. Christ child El Nino patterns are first recognized during the Christmas season. Complex interactions between the Earth’s Physical Biological Chemical environments . El-Nino Geography.
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Climate Change El-Nino Southern Oscillation (ENSO) Phenomena
El Nino • Christ child • El Nino patterns are first recognized during the Christmas season. • Complex interactions between the Earth’s • Physical • Biological • Chemical environments
Physical conditions • Atmosphere • Ocean circulation pattern • Ocean surface temperatures
The atmosphere • Trade winds feed into, • Walker cell • Hadley cell • Resulting precipitation patterns
Normal Conditions Walker Cell Equator Sea level Thermocline Upwelling Conditions
The Atmosphere/Ocean connection • Feed off one another, • Makes for a very complex story • Overhead!
Pacific Ocean surface currents • Driven by atmospheric circulation • North Equatorial (NEC) • South Equatorial (SEC) • North Equatorial Counter Current (NECC) • Peru Current
SST, Sea surface temperatures • Key identifier of a changing climate. • Non El Nino years • Coastal Peru • Winter 18 C (25 C) • Coldest tropical water on Earth • TAO array of moored buoys.
Important subsurface currents • Equatorial Undercurrent • The Peru surface current and equatorial upwelling.
Upwelling along western coast of South America • Influx of Antarctic water, August (winter). • Brings nutrients to the surface • Producing abundant diversity • Plankton • Anchovies • Tuna • Sea birds • Marine mammals
Cool dry air sinks Warm moist air rises Indonesia South America
El Nino phenomenon leads to dramatic changes • Starts with: Failure of southern trade winds around December • Warming of the ocean off Peru • Decrease in bio-productivity off Peru • Increase in eastern Pacific rainfall • Decrease in western Pacific rainfall • Development of winds from the west
El-Nino History • Approx. 5,000 years ago the cycle begins • Recurrence interval, 2 to 7 years • Over the past 465 years, there have been 9 severe El-Nino events. (Avg. 1 event per 50 years)
El-Nino Bi-products • Flooding in South America (Peru) • Drought/wildfires in Indonesia and Australia • Variable effects throughout the United States.