learn how El Niño and La Niña work u emphasize that the ocean & atmosphere are strongly coupled u understand that one component of the Earth’s system can have drastic effects on the rest of the Earth Unusual oceanic and atmospheric phenomenon - an anomaly ,We don’t know everything about it ,We can’t really predict it yet | 1 1 1 Objectives learn how El Niño and La Niña work emphasize that the ocean & atmosphere are strongly coupled understand that one component of the Earth’s system can have drastic effects on the rest of the Earth El Niño: The Enigma Unusual oceanic and atmospheric phenomenon - an anomaly We don’t know everything about it We can’t really predict it yet El Niño: The Term First discovered in 1795 Recognized by local fisherman along Ecuador and Peru Warm, surface countercurrent North-->South Discovered around Christmas-time “The Christ Child” El Niño Characteristics Normally develops in W. tropical Pacific Often results in natural disasters Occurs every 2 to 10 years Most recent and severe events in 1953, ‘57-’58, ‘65, ‘72-’73, ‘76-’77, ‘82-’83, ‘91-’92, ‘97-’98, ‘02-’04, ‘06-’07, ’09’10 Slides from 1982-’83 El Niño -09-’10 INDEX = Air temperature Sea surface temp Surface winds Cloudiness of sky Sea level pressure Pressure!! Suppressed Sea Surface Elevated Sea Surface Tradewinds weaken or fail Tropical winds reverse and go east instead of west Atmospheric pressure cells reverse Wet areas become dry (drought) Dry areas get flooded “oscillates” like a giant sea-saw, taking 3-5 months “Southern Oscillation” (SO) Non El Niño El Niño Non El Niño El Niño Coupled Ocean-Atmosphere Circulation Ocean’s Response to the SO Warm water moves to the east Elevates sea surface temperatures (SSTs) in SE Pacific Shuts down upwelling, can induce downwelling Reduces available nutrients Kills fish and sea birds - especially bad off Peru El Niño Non El Niño Animations Ocean AND Atmosphere El Niño is both an oceanic and an atmospheric phenomenon Often called ENSO Scientists knew of SO from wind and precip. data Scientists knew of El Niño from SST data Didn’t make connection until 1969 Jacob Bjerknes Jacob Bjerknes, a Norwegian meteorologist made breakthrough in 1969 Combined wind, rain, AND SST data Ocean & atm. part of “big climate engine” Effects of ENSO not just local to Peru but could . | 1 1 1 Objectives learn how El Niño and La Niña work emphasize that the ocean & atmosphere are strongly coupled understand that one component of the Earth’s system can have drastic effects on the rest of the Earth El Niño: The Enigma Unusual oceanic and atmospheric phenomenon - an anomaly We don’t know everything about it We can’t really predict it yet El Niño: The Term First discovered in 1795 Recognized by local fisherman along Ecuador and Peru Warm, surface countercurrent North-->South Discovered around Christmas-time “The Christ Child” El Niño Characteristics Normally develops in W. tropical Pacific Often results in natural disasters Occurs every 2 to 10 years Most recent and severe events in 1953, ‘57-’58, ‘65, ‘72-’73, ‘76-’77, ‘82-’83, ‘91-’92, ‘97-’98, ‘02-’04, ‘06-’07, ’09’10 Slides from 1982-’83 El Niño -09-’10 INDEX = Air temperature Sea surface temp Surface winds Cloudiness of sky Sea level pressure Pressure!! Suppressed Sea Surface Elevated Sea Surface Tradewinds weaken or
