The 2002 El Niño Forecast
Olympics is About to Get Under Way
Michael H. Glantz
12 February 2002
The longest La Niña in decades has waned, so we are told by those who monitor the changes in Pacific Ocean sea surface and subsurface temperatures. They watch a host of indicators: changes in the thermocline's depth across the equatorial Pacific, the difference in sea level at Darwin (Australia) and Tahiti, surface wind speed and direction in the tropical Pacific, the aerial coverage of the warmed surface water, and so on.
Today the collection of such indicators and the computer model runs of more than a dozen research groups seeking to forecast the behavior of the ENSO cycle months in advance suggest that La Niña is on its way out. If it is, can an El Niño be far behind?
Some observers suggested that there was likely to be an El Niño in 2001 (I was one of them!). It didn't happen. Now, some forecast groups are suggesting that there could be the onset of a warm event under way now in February 2002 to become a moderate event by the end of this year. How much of what we are hear about the onset of an El Niño is guesswork?
Once it is certain that the La Niña episode of 1998 -2000 has ended and that sea surface temperatures (SSTs) are "warming past neutral," speculation will grow with every squiggle of the SSTs in the tropical Pacific. "The squiggle is upward this week! El Niño is coming!" "The squiggle turns downward, La Niña may return!" This is the kind of news we heard in November 1997 during the development of the El Niño of the Century.
To my mind, this was rather irresponsible reporting by the media and irresponsible comments by scientists who provided the media with such an interpretation of changes in conditions in the tropical Pacific. Forecasting climatic phenomena on weather time scales (hours to days) is not really a good idea.
Looking on the Internet for news stories on El Niño, one finds mostly old stuff relating to the 1997-98 event. All that is about to change. The media, to be sure, will pounce on El Niño as a newsworthy event, once a reputable scientist declares that an event is about to begin. Researchers, forecasters, and speculators about the climate are all preparing for the next event.
Those of us who deal with El Niño are in a position as evaluators of these events to say anything we wish about it and much of the public will accept it. That being the case, we must approach what we say about the ENSO cycle with great care.
A growing number of examples of forecasts have caused considerable controversy relating to interpretations placed on the forecast by the media (e.g., US, Australia, Brazil). How best to communicate a forecast and how the media should translate that into language the public can use without causing undue alarm (or undue inattention!) has become an issue of great concern in scientific circles. We had best think about how we will discuss our interpretations of those changes in the Pacific in a responsible and reliable way. Perhaps by doing so we can avoid the charges of media "hype" and scientific mis-statements that came with the last El Niño in 1997-98.
|Fragilecologies Home Page | Full List of Articles|