El Nino: What’s It All About?
ENSO: El Nino Southern Oscillation
January 31, 1998
What is El Nino?
• warming of sea surface
waters in the eastern
Pacific Ocean caused by
slowing of Pacific gyre
• “warm phase”, occurs
every 3-7 years
• the shift in temperatures
dramatically affects
global weather
Occurs during Christmas season ...
• First noticed by
Peruvian Fishermen
• “Christ Child”
• “The Boy”
• “The Little One”
Common Effects of El Nino?
• US southwest wetter
• US northwest mild
winters
• Atlantic hurricanes
milder and less
frequent
• African droughts or
floods
• European droughts
and floods
• East asian floods
Vietnam Has Been Hit by Flood and
Drought in 2002.
U.S. had worst fire year in last 50; this
photo from Angeles National Forest
What is La Nina?
• cooling of sea
surface waters in the
eastern Pacific
Ocean caused by
speeding up of
Pacific gyre
• “cold phase”, occurs
every 3-7 years
More El Nino
Images
Spring
El Nino
Normal
Autumn
El Nino
National El Nino Impact
Measuring El Nino
Weather Station: Colorado
Measuring El Nino
Buoys
The World’s Largest Scientific Instrument!
Tropical Atmosphere Ocean (TAO) Array of ATLAS moored buoys
Measuring El Nino
Satellites
Measuring El Nino
Sea Surface Temperatures
Measuring El Nino:
Coral Bleaching
El Nino and California
• Increased chance of heavy winter rains
• Severe flooding and landslides
(1934, La Canada floods kill more than 40 people; 1978
killer landslides in local mountains)
• Bigger surf from larger Pacific Storms
• Increased summer droughts
A rescuer helps a woman out of her
Orange County house, 1998