News Archive

posted 08/12/02

Scientists Say New El Niño "Almost Certain" in Coming Months
Efforts underway at Earth Institute to predict and minimize costs and damage

A) Latest Sea Surface Temperature (departure from average, deg. )

El Niño is back, and some abnormal weather can be expected in the coming six to nine months. A team of Columbia climate experts at the International Research Institute for Climate Prediction has identified the warm Pacific ocean surface temperatures indicating that the climate phenomenon has indeed returned (see Image A below). IRI researchers are now engaged in the delicate task of forecasting which locations are most vulnerable to the extremes that can accompany an El Niño, and what people in those locations can do to prepare. Indicators of an El Niño and its Global Influence on Weather and Society is the topic of this year’s Open House at the Lamont Doherty Earth Observatory on Saturday, October 5th.

"Right now we expect this year's disturbance to be considerably weaker than the 1997-98 El Niño," says Steve Zebiak, Director of Modeling and Prediction at the IRI, part of the Earth Institute at Columbia. Zebiak was part of the team that successfully predicted a developing El Niño for the first time in history in 1986-87.

Stephen E. Zebiak, Ph.D.

What might this year's El Niño mean for people in the U.S. and around the world? "The extreme southern U.S. - Arizona, Southern California, Southern New Mexico and Texas - should get some relief from their dry conditions," according to IRI climate expert Tony Barnston. In isolated locations mudslides and flooding could occur. In the great lakes region and Northern New England conditions are likely to be milder and drier than average this winter, which could be bad news for areas such as Chicago and Detroit, which are already experiencing unusually dry weather.

Some good news: According to Barnston, El Niño reduces Atlantic hurricanes, so this fall's storm season could be a mild one.

Image B below indicates areas around the world where drier or wetter conditions exist as of July 2002. In some of these areas vulnerable conditions, such as drought or wetness, may be exacerbated by a new El Niño; in others the El Niño may alleviate current problems.

B)

El Niño may already be producing dry conditions in Eastern Australia, and Southern Africa is likely to experience a drier than normal rainy season this winter. This could have serious implications for already fragile economies such as that in Zimbabwe, where drought and crop failures were threatening famine even before the El Niño.

By contrast in Ghana, which has been experiencing below normal rainfall, rainfall is expected to be higher than average over the next few months.

Tricky as it is to forecast an El Niño phenomenon, it is even more difficult to foretell, not to mention prevent, potential damage from its effects. Image C below shows disasters, both wet and dry, that occurred during the last El Niño in 1997/8. Whether the same locations will experience any difficulties in this gentler El Niño season is impossible to predict.

C) Declared El Niño Related Disasters. 1998
(Click on image above for larger version)

Green and brown areas represent drier and wetter than normal for February, 1998.

Nevertheless, scientists at the IRI believe that by receiving and sharing information about climate forecasts as well as developing weather conditions, localities around the world will have the best chance of avoiding billion-dollar damage like that which occurred in the 1997-8 El Niño. Forecasters are becoming more skillful, and those who might use climate outlook information (farmers and fishermen, as well as emergency fire and flood managers, and those responsible for policy decisions influencing the use of water and other resources) are learning to use probabilistic forecasts.

A group of the scientists and Earth Institute Director Jeffrey Sachs will be travelling to Washington D.C. on September 30 to talk to ambassadors and funding and aid agencies who are in a position to begin planning for the devastating droughts, floods, mudslides, and other impacts of an El Niño that could be seen in vulnerable regions of the world. Last spring, the IRI began to encourage regional planning and information sharing at an international conference held at its headquarters on the Lamont campus.

A visitor to El Niño Web on the IRI website (http://iri.columbia.edu) will find discussions of every aspect of El Niño and the Southern Oscillation, collectively known as ENSO. The site covers both the scientific inputs used by ENSO modelers to support predictive work, and discussions of human outcomes such as ties to maize yields in Zimbabwe, rice yields in Sri Lanka, and brown locust outbreaks in Southern Africa.

The International Research Institute for Climate Prediction aims to improve quality of life and environmental sustainability through the use of climate information, including climate forecasts. From climate forecasting and modeling to fishery management, IRI researchers focus on where climate information and public policy intersect. By collaborating with societies to make climate a routine part of regional planning and decision-making, the IRI works to enable communities to better manage the challenges posed by climate fluctuations. For more information, visit http://iri.columbia.edu.