Article: "Variability in the El Nino - Southern Oscillation (ENSO) Through a Glacial-Interglacial Cycle."
- ENSO is the most potent source of interannual climate variability.
- ENSO has existed for the past 130,000 years.
- ENSO stronger in the 20th century compared with previous cool and warm times.
Source: Science, Volume 291, Number 5508.
Date: 2001 February 23
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Article: "Super ENSO and Global Climate Oscillations at Millenial Time Scales."
- Since last glacial maximum, 22,000 years ago, sea surface temperatures of tropical Pacific ocean have warmed about 2 degrees Celcius (summer) and 3 degrees (winter).
- Variability of tropical Pacific temperature over past glacial period (22,000 years ago to 64,000 years ago) average 1-2 degrees celcius.
- In western tropical Pacific, ocean was saltier through much of past 70,000 years than today.
- Millennial-scale El Nino-like conditions may have shifted atmospheric convection away from west tropical Pacific, explaining lower atmospheric carbon dioxide, N2O, and methane during stadial periods.
Source: Science, Volume 297, Number 5579.
Date: 2002 July 12
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Article: "El Nino-Like Pattern in Ice Age Tropical Pacific Sea Surface Temperature."
- Sea surface temperatures of the eastern equatorial Pacific exert powerful controls on global atmospheric circulation patterns.
- Sea surface temperatures varied consistently with Earth's orbital precession-induced changes in seasonality during past 30,000 years.
Source: Science, Volume 297, Number 5579.
Date: 2002 July 12
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Article: "The Pliocene Paradox (Mechanisms for a Permanent El Nino)."
- 3 to 5 million years ago, globally averaged temperatures were substantially higher than today, atmospheric carbon dioxide was similar, but surface temperature at poles was higher that Northern Hemisphere had no continental glaciers.
- Amplification of response of climate to orbital forcing began 3 million years ago, resulting in drastic oscillations between ice ages and warmer periods over the past 1 million years.
- El Nino was continual rather than intermittent up to 3 million years ago.
- A persistence of high carbon dioxide concentrations could result in return to globally warm world.
Source: Science, Volume 312, Number 5779.
Date: 2006 June 9
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Article: "Intense hurricane activity over the past 5,000 years controlled by El Nino and the West African Monsoon."
- Processes controlling formation, intensity, track of hurricanes poorly understood.
- Frequency of intense hurricane landfalls has varied on centennial to millennial scales over 5000 years.
- Variability probably modulated by El Nino / Southern Oscillation and West African monsoon.
- Sea surface temperature of present not necessary to support intervals of frequent intense hurricanes.
Source: Nature, Volume 447, Number 7143.
Date: 2007 May 24
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