Climate ChangeClimate ChangeEl-NinoEl-Nino

Southern Oscillation Southern Oscillation (ENSO)(ENSO)

Phenomena Phenomena

El-NinoEl-Nino

El NinoEl Nino

►Christ child Christ child ►El Nino patterns are first recognized El Nino patterns are first recognized

during the Christmas season. during the Christmas season. ►Complex interactions between the Complex interactions between the

Earth’s Earth’s Physical Physical BiologicalBiological Chemical environments Chemical environments

El-Nino GeographyEl-Nino Geography

Physical conditionsPhysical conditions

►AtmosphereAtmosphere►Ocean circulation patternOcean circulation pattern

Ocean surface temperatures Ocean surface temperatures

The atmosphere The atmosphere

►Trade winds feed into, Trade winds feed into, Walker cellWalker cell Hadley cellHadley cell

► Resulting precipitation patternsResulting precipitation patterns

Equator

Sea level

Thermocline

Upwelling

Conditions

Normal Conditions

Walker Cell

The Atmosphere/Ocean The Atmosphere/Ocean connectionconnection

► Feed off one another, Feed off one another, Makes for a very complex storyMakes for a very complex story Overhead!Overhead!

Pacific Ocean surface Pacific Ocean surface currents currents

►Driven by atmospheric circulation Driven by atmospheric circulation ►North Equatorial (NEC)North Equatorial (NEC)►South Equatorial (SEC) South Equatorial (SEC) ►North Equatorial Counter Current North Equatorial Counter Current

(NECC)(NECC)►Peru Current Peru Current

SST, Sea surface SST, Sea surface temperaturestemperatures

► Key identifier of a Key identifier of a changing climate.changing climate.

►Non El Nino yearsNon El Nino years Coastal Peru Coastal Peru Winter 18 Winter 18 C (25 C (25 C)C) Coldest tropical Coldest tropical

water on Earthwater on Earth

► TAO array of TAO array of moored buoys. moored buoys.

TAO array of moored buoysTAO array of moored buoys

Important subsurface Important subsurface currentscurrents

► Equatorial UndercurrentEquatorial Undercurrent► The Peru surface current and equatorial The Peru surface current and equatorial

upwelling. upwelling.

Upwelling along western coast Upwelling along western coast of South America of South America

► Influx of Antarctic Influx of Antarctic water, August (winter). water, August (winter).

► Brings nutrients to the Brings nutrients to the surfacesurface

► Producing abundant Producing abundant diversitydiversity PlanktonPlankton AnchoviesAnchovies TunaTuna Sea birdsSea birds Marine mammals Marine mammals

Warm moist air rises

Cool dry air sinks

Indonesia South America

El Nino phenomenon leads to El Nino phenomenon leads to dramatic changesdramatic changes

1)1) Starts with: Failure of southern trade Starts with: Failure of southern trade winds around December winds around December

2)2) Warming of the ocean off PeruWarming of the ocean off Peru

3)3) Decrease in bio-productivity off PeruDecrease in bio-productivity off Peru

4)4) Increase in eastern Pacific rainfallIncrease in eastern Pacific rainfall

5)5) Decrease in western Pacific rainfallDecrease in western Pacific rainfall

6)6) Development of winds from the westDevelopment of winds from the west

NOAA, National Oceanic and NOAA, National Oceanic and Atmospheric Administration Atmospheric Administration

El-Nino History El-Nino History

► Approx. 5,000 years ago the cycle Approx. 5,000 years ago the cycle beginsbegins

► Recurrence interval, 2 to 7 yearsRecurrence interval, 2 to 7 years► Over the past 465 years, there have Over the past 465 years, there have

been 9 severe El-Nino events. (Avg. 1 been 9 severe El-Nino events. (Avg. 1 event per 50 years) event per 50 years)

El-Nino Bi-products El-Nino Bi-products

►Flooding in South America (Peru)Flooding in South America (Peru)►Drought/wildfires in Indonesia and Drought/wildfires in Indonesia and

AustraliaAustralia►Variable effects throughout the United Variable effects throughout the United

States. States.

Ecuador