Facts about ENSO:

• Originates in the tropical Pacific
• Has a periodicity of 2-7 years
• Affects the global atmospheric circulation
• During the warm phase of ENSO, called "El Niño", sea surface temperatures warm, trade winds collapse, and precipitation patterns shift
• During the cold phase of ENSO, referred to as "La Niña", sea surface temperatures cool and trade winds strengthen

ENSO Effects on the US:

El Niño:

• Warmer winters across the northern US
• Gulf states cooler and wetter
• California can be wetter or drier
• Pacific salmon and other fisheries disrupted
• Fewer hurricanes in the Atlantic

La Niña:

• La Niña has equally dramatic, often opposite effects on the US

ENSO is Predictable:

• Computer models show skill in forecasting tropical Pacific Ocean temperatures one to two years in advance
• ENSO forecasts improve the accuracy of seasonal and longer forecasts over the US
• Potential for billions of dollars in benefits to the US economy in:
  • Agriculture
    
  • Energy generation
    
  • Water resources
    
  • Forestry
    
  • Fisheries
    
  • Transportation
    
  • Commerce
    
  • Public health
    

What is needed?

• Long term operational support for Pacific Ocean observations that are the foundation of skillful ENSO forecasts:
  • Moored buoys
    
  • Drifting buoys
    
  • Volunteer ship temperature probes
    
  • Sea level measurements
    
• Total cost of these ocean observations is $4.9 million per year

To obtain a hard copy of this page just copy this postscript file and direct it to your color postscript printer. If for some reason this doesn't work, you can also ftp the postscript file interactively by following these instructions. See these links for Further Reading and Additional information

Michael J. McPhaden, michael.j.mcphaden@noaa.gov, 20 March 1997