ENSO El Niño Southern Oscillation Pages 484-487. NORMAL conditions Trade Winds Cool water pools near S.America, Warm water pools near Australia.

ENSO

El Niño Southern Oscillation

Pages 484-487

NORMAL conditionsNORMAL conditionsTrade WindsCool water pools near S.America,Warm water pools near Australia

El Nino Warning SystemEl Nino Warning System

• Sea Surface Temperature

•Wind Speed/Direction

•Ocean Current Direction

EL NINO

How are “El Niño” conditions different?

Ocean currents reversesWarm water pools near S.AmericaCool water pools near Australia

How does El Nino affect weather in…

• South America?

• Australia?

• Northern US?

• Southern US?

• Typhoons?

Global Effects of El Nino

S. America- more rain; warmerFloods/mudslides

Australia- dry; coolerLess typhoonsKills anchovies in Peru (how El Nino was first

discovered)

El Nino’s effect on the United States

Warmer winters/ drier in N states

Wet/colder Wet/colder winters in S states

“LA NINA”

Cool phase of ENSO (neg. phase)Trade winds intensify

La Nina

How does La Nina affect weather in…

• South America?

• Australia?

• Northern US?

• Southern US?

• Hurricanes?

• South America- drier/colder

• Australia- wetter/warmer

• N. US- Colder than normal winters»Increased snowfall

More hurricanes

S. US- warmer/drier

La Nina’s effects

Predictable?

El Nino or La Nina?

2012-2013 winter forecast(as of Oct. 2012)

El Nino or La Nina?

Winter 2012

normal 2012

• Plus el Nino

Helpful Websites

• TAO ~ Tropical Atmosphere Ocean project

http://www.pmel.noaa.gov/tao/index.shtml

• The TAO Story

http://www.pmel.noaa.gov/tao/proj_over/flash/mainDOC.html