ENSO Observations Mike McPhaden NOAA/PMEL Seattle, Washington
CLIVAR ENSO Workshop Paris, France 17-19 November 2010
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Observations Required for Description, Understanding and
Prediction
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87% Total in situ networksMay 200860% 62% 81% 43% 79% 48%24%
Initial Global Ocean Observing System for Climate Status against
the GCOS Implementation Plan and JCOMM targets 100% GOOS
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A Short History of ENSO Observations Paleo Proxies Instrumental
1850s Matthew Fontaine Maury 1950s IGY & Bjerknes 1960s
Satellite era for weather 1980s AVHRR, Geosat altimetry 1985-94
TOGA 1990s High precision altimetry, scatterometry 30 years of
systematic subsurface ocean and satellite observations for
describing, analyzing and developing forecasting capabilities for
ENSO
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Global Tropical Array Current Conditions
http://www.pmel.noaa.gov/tao/
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Global Tropical Array Current Conditions
http://www.pmel.noaa.gov/tao/
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Global Tropical Array El Nio vs La Nia
http://www.pmel.noaa.gov/tao/
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Recharge Oscillator Theory (Wyrtki, 1985; Cane et al, 1986;
Jin, 1997) Meinen & McPhaden, 2000
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Build up of excess heat content along equator is a necessary
precondition for El Nio to occur. The time between El Nios is
determined by the time to recharge. El Nio purges excess heat to
higher latitudes, which terminates the event. Upper Ocean Heat
Content and ENSO After Meinen & McPhaden, 2000 Heat content
based on TAO/TRITON, XBT and Argo data
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Global Tropical Array Upper Ocean Heat Content and ENSO Upper
ocean heat content variations are the source of predictability for
the ENSO cycle Heat content based TAO/TRITON, XBT and Argo data
After Meinen & McPhaden, 2000
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Lead Time Changes
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Seasonality of Lead Time Changes McPhaden,, 2003: Tropical
Pacific Ocean heat content variations and ENSO persistence
barriers. GRL
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Trends in Central Pacific El Nio SSTs SST anomaly Dec 2009
Central Pacific El Nios are increasing in frequency and amplitude
Lee & McPhaden, Geophys. Res. Lett., 2010 Nio-4 SST
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EP vs CP El Nios 3/5 EP 3/4 CP
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Ratio of CP/EP El Nios Increases Under Global Warming Yeh et
al, Nature, 2009 Mean Thermocline Depth
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Changes in Background Conditions
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Differences in El Nio Composites EP CP CP-EP
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Mean State El Nio Statistics? MeanENSO ?
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Summary 30 years of systematic subsurface ocean and satellite
observations available for detailed studies of ENSO and its decadal
modulation Lead time of ocean heat content (WWV) a predictor of
ENSO SST has decreased from 2-3 seasons to ~1 season in the first
decade of the 21 st century Loss of predictability concentrated
early in the calendar year Changes correspond to increasing
incidence of CP El Nios Corresponds to decadal changes in
background conditions (winds, thermocline depth, SST) Natural
variability? Influence of global warming? CLIVAR ENSO Workshop
Paris, France 17-19 November 2010
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And in the future?
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Global Tropical Array Global Tropical Moored Buoy Array: A
coordinated, sustained, multi-national effort to develop and
implement moored buoy observing systems for climate research and
forecasting throughout the global tropics A contribution to GOOS,
GCOS, and GEOSS TRITON ATLAS Key attributes: Real-time
Ocean-atmosphere High temporal resolution Basin scale
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Eastern vs Central Pacific (Modoki) El Nios Central Pacific(M
odoki) Eastern Pacific Ashok, 2009 Nio-3.4 Nio-4
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A Short History of ENSO Observations Paleo proxy Instrumental
1850s Matthew Fontaine Maury 1950s IGY & Bjerknes 1960s
Satellite era for weather satellites 1980s AVHRR, Geosat altimetry
1985-94 TOGA 1990s High precision altimetry, scatterometry
