GEO130 – OCEANOGRAPHY

El Niño Study Guide

Updated 08.24.09

 

Pacific Ocean
Atmospheric Winds
and
Ocean Currents
that play a role in
El Niño - Southern Oscillation

NE Trade Winds (N.Hemi)
and
SE Trade Winds (S.Hemi)
translucent white
RECORD OF ENSO EVENTS
Warm Phase Cold Phase
Subtropical High
Pressure Cell
WEAK
Subtropical High
Pressure Cell
STRONG
Trade Winds
WEAK
Trade Winds
STRONG
Upwelling
WEAK
Upwelling
STRONG
Sea Level
Western Pacific
FALLING
Sea Level
Western Pacific
RISING
Equatorial Counter Current
STRONG
Equatorial Counter Current
WEAK
Biological Impact
Primary Productivity
REDUCED
WHY?
Biological Impact
Primary Productivity
INCREASED
WHY?
TYPICAL WARM
EPISODES
= "El Niño"
TYPICAL COLD
EPISODES
= "La Niña"
1982 - 1983
Warm Episode
1988 - 1989
Cold Episode
1997 - 1998
Warm Episode
1998 - 1999
Cold Episode
RAINFALL ANOMALIES
97-98 El Niño
SEA LEVEL CHANGES
ENSO CYCLE
Above:
Cool Phase
Above:
Warm Phase
World Impacts
El Niño -
Southern Oscillation
NORTHERN WINTER
World Impacts
El Niño -
Southern Oscillation
NORTHERN SUMMER