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National Oceanic and Atmospheric Administration

The Top 10 El Niño Events
of the 20th Century

Climate Perspectives Branch, Global Climate Lab
National Climatic Data Center, Asheville, NC
June 4, 1998
Top 10 El Niño Events Global Surface Temperature Anomalies this Century
Global temperature anomalies during the ten strongest El Niños of the Twentieth Century are shown above. The width of the bar represents the character of the event. El Niño events have a duration varying between half a year to a year and a half. Over recent years, El Niño events have become more frequent as the global temperature anomalies associated with each El Niño continue to increase. This means that the extreme regional weather and climate anomalies associated with El Niño are being exacerbated by increasingly higher temperatures. The warmer conditions have been linked to higher concentrations of atmospheric greenhouse gases.

El Niño events were based on work described in: Livezey et al., 1997: Teleconnective response of the Pacific-North American region atmosphere to large central equatorial Pacific SST anomalies, J. Climate, 10, 1787-1819.

Top of Page Land Data Anomalies

    Year.mid  deg.C   deg.F   duration
                              in months
    1915.08   0.017   0.031    11.0
    1918.00  -0.012  -0.022     8.0
    1941.55   0.141   0.253    15.0
    1958.12   0.278   0.500     9.0
    1966.00  -0.007  -0.013     8.0
    1973.00   0.237   0.426     6.0
    1983.05   0.393   0.707     7.0
    1987.12   0.337   0.606     6.0
    1992.08   0.526   0.947    10.0
    1997.75   0.835   1.502    13.0
    

Top of Page Ocean Data Anomalies

    Year.mid  deg.C   deg.F   duration
                              in months
    
    1915.08  -0.051  -0.092   11.0
    1918.00  -0.100  -0.180    8.0
    1941.55   0.177   0.319   15.0
    1958.12   0.212   0.382    9.0
    1966.00   0.071   0.127    8.0
    1973.00   0.229   0.412    6.0
    1983.05   0.333   0.599    7.0
    1987.12   0.220   0.397    6.0
    1992.08   0.255   0.458   10.0
    1997.75   0.523   0.942   13.0
    

Top of Page Land and Ocean Data Combined into an Anomaly Index

    Year.mid  deg.C   deg.F   duration
                              in months
    
    1915.08  -0.031   -0.055    11.0
    1918.00  -0.074   -0.133     8.0
    1941.55   0.166    0.299    15.0
    1958.12   0.232    0.417     9.0
    1966.00   0.047    0.085     8.0
    1973.00   0.231    0.416     6.0
    1983.05   0.351    0.632     7.0
    1987.12   0.255    0.459     6.0
    1992.08   0.336    0.605     10.0
    1997.75   0.617    1.110     13.0
    

The average annual temperature of the globe is about 59 deg. F (15 deg. C). That value can be added to global anomalies to approximate absolute temperatures. Anomalies (also called departures from average) are used because they describe more accurately climatic variability over large areas than the absolute temperatures do and they give a frame of reference that allows for easier interpretation of the numbers. For example, a summer month over a large area may be cooler than average, both at a mountain top and in a nearby valley, but the absolute temperatures may be quite different at the two locations. The use of anomalies in this case will show that temperatures for both locations were below average. For these reasons, it is the anomalies that are computed for large-area summaries (like a hemisphere or the globe), not the temperature itself.

An analogy using human body temperatures might help to explain why anomalies are useful. The "average" human body temperature is about 98.6 deg. F. But some people have lower normal temperatures than others. For someone with a normal body temperature of 98.0 deg. F., a temperature reading of 98.6 deg. would indicate a fever. The use of 98.6 deg. alone would not indicate this condition to most people but the use of an anomaly or departure from the normal body temperature for this person (+0.6 deg. F) would indicate the feverish condition.

NOAA's El Niño Page
NOAA's El Niño Page
El Niño Theme Page
Accessing Info related to El Niño
NCEP/CPC El Niño Page
El Niño/Southern Oscillation

For further information on the El Niño Events, contact:

    Mike Crowe
    NOAA/National Climatic Data Center
    151 Patton Avenue
    Asheville, NC 28801-5001
    fax: 828-271-4328
    email: michael.crowe@noaa.gov

    - or -

    Thomas Peterson
    NOAA/National Climatic Data Center
    151 Patton Avenue
    Asheville, NC 28801-5001
    fax: 828-271-4328
    email: thomas.c.peterson@noaa.gov

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NCDC / Climate Resources / Climate Perspectives / El Niņo / Top 10 Events / Search / Help

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