El Nino!El Nino!

By: Katie Durham & Mike By: Katie Durham & Mike MagnusonMagnuson

The Climate Event of the Century

Que es el nino?Que es el nino?• El Nino is a crucial climatic El Nino is a crucial climatic disturbance of the ocean and the disturbance of the ocean and the atmosphere.atmosphere.

• Characterized by a large scale Characterized by a large scale deterrent of the trade winds and deterrent of the trade winds and warming of the surface areas in warming of the surface areas in the central and east equatorial the central and east equatorial Pacific.Pacific.

• Usually occurs at intervals of 2-7 Usually occurs at intervals of 2-7 years, averaging every 3-4 years, years, averaging every 3-4 years, lasting 12-18 months at a time.lasting 12-18 months at a time.

When did El Nino occur?When did El Nino occur?

•It has always been a natural, It has always been a natural, world-wide phenomenon.world-wide phenomenon.

•Strongest El Nino intensity Strongest El Nino intensity occurred from 1982-83 and 1997-occurred from 1982-83 and 1997-98.98.

•Impacts seen most clearly in Impacts seen most clearly in the winter.the winter.

Before and AfterBefore and After

• Made with a Made with a coupled ocean-coupled ocean-atmosphere model atmosphere model of the tropical of the tropical Pacific Pacific

• Data is Data is collected using collected using tide gauge tide gauge stationsstations

Delayed Oscillator TheoryDelayed Oscillator Theory

• Theory of originTheory of origin• El Nino is due to rossby waves, El Nino is due to rossby waves, which are reflected from the which are reflected from the western boundary of the western boundary of the atmospheric system.atmospheric system.

• Causes kelvin waves to propagate Causes kelvin waves to propagate eastward, driving the cold water eastward, driving the cold water that gives rise to El Nino.that gives rise to El Nino.

E.N.S.O.E.N.S.O.• ““El Nino Southern El Nino Southern Oscillation”Oscillation”

• Multi-annual shift Multi-annual shift in tropical sea in tropical sea level pressure level pressure between the eastern between the eastern and western and western hemispheres.hemispheres.

• Events monitored by Events monitored by satellites.satellites.

El Nino v. La NinaEl Nino v. La Nina• Antipodes of one Antipodes of one another.another.

• La Nina brings colder La Nina brings colder than normal sea than normal sea surface temperatures surface temperatures in the equatorial in the equatorial Pacific. Pacific.

• It also causes drier, It also causes drier, warmer conditions to warmer conditions to much of the southern much of the southern U.S. during winter.U.S. during winter.

Impacts of El Nino in Impacts of El Nino in the U.S.the U.S.

• Winter temperatures in the Winter temperatures in the continental U.S. tend to be warmer continental U.S. tend to be warmer than normal in the N and W coast than normal in the N and W coast states and cooler than normal in the states and cooler than normal in the SE. SE.

• Conditions tend to be wetter than Conditions tend to be wetter than normal over central and southern normal over central and southern California, the SW states and across California, the SW states and across much of the South. much of the South.

• Conditions are drier than normal Conditions are drier than normal over the N portions of the Rocky over the N portions of the Rocky Mountains and in the Ohio valley. Mountains and in the Ohio valley.

Global effects of Global effects of El NinoEl Nino

• El Nino brings El Nino brings wetter than normal wetter than normal conditions to Peru conditions to Peru and Chile.and Chile.

• It brings dry It brings dry conditions to conditions to Australia and Australia and Indonesia. Indonesia.

El Nino: 1997-1998El Nino: 1997-1998• Lasted 14 months.Lasted 14 months.• Largest and warmest El Largest and warmest El

Nino to develop during Nino to develop during the past 100 years.the past 100 years.

• Received more Received more attention at all attention at all levels than had any levels than had any previous climate previous climate event.event.

• Scientists were able Scientists were able to use El Nino to use El Nino conditions to conditions to successfully predict successfully predict climate conditions of climate conditions of the winter 6 months in the winter 6 months in advance.advance.

Works CitedWorks Cited• Caviedes, Cesar N. Caviedes, Cesar N. El Nino in History: Storming El Nino in History: Storming

Through the AgesThrough the Ages..Gainesville: University P of Florida, 2001. 46-49.Gainesville: University P of Florida, 2001. 46-49.

• Changnon, Stanley A., ed. Changnon, Stanley A., ed. El Nino: 1997-1998El Nino: 1997-1998. New . New York City: Oxford UP,York City: Oxford UP,2000. 3-4. 2000. 3-4.

• D'Aleo, Joseph S. D'Aleo, Joseph S. The Oryx Resource Guide to El The Oryx Resource Guide to El Nino and La NinaNino and La Nina..

Westport, Conneticut: Oryx P, 2002. 9-17.Westport, Conneticut: Oryx P, 2002. 9-17. • "El Nino and La Nina." "El Nino and La Nina." World Almanac and Book of World Almanac and Book of

FactsFacts. 2004: 701-702.. 2004: 701-702.Academic Search Premier. Dayton. 25 Mar. 2004 Academic Search Premier. Dayton. 25 Mar. 2004