Brian Dunbar
Headquarters, Washington, D.C.                			Sept. 22, 1995
(Phone:  202/358-1547)

Ernie Shannon
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-6256)

RELEASE:  95-188 (159)

SCIENTISTS SAY EL NINO CAN NOW BE PREDICTED A YEAR IN ADVANCE
 
      Recent advances in computer models and how they use ocean data now 
allow predictions of El Nino -- a dramatic climate shift that can affect 
weather and economies worldwide -- to be made more than a year before the 
event, new NASA, NOAA and university research indicates.

      "Certain aspects of El Nino, such as equatorial Pacific sea-surface 
temperatures and related changes in precipitation patterns can now be 
predicted with confidence more than one year in advance," said Dr. Antonio 
Busalacchi of NASA's Goddard Space Flight Center, Greenbelt, Md.

      The new study used data from the ten-year Tropical Ocean Global 
Atmosphere (TOGA) project, an international research program that studied 
how Earth's oceans and atmosphere affect one another.  The team's paper 
will be published today in the journal "Science."  Busalacchi's co-authors 
are Dr. Dake Chen, University of Rhode Island, and Dr. Stephen Zebiak and 
Dr. Mark Cane of Columbia University's Lamont Doherty Earth   Observatory, 
Palisades, N.Y.

      TOGA has successfully completed its decadal mission and the world 
legacy of the Topical Atmosphere Ocean array and all the research 
infrastructure is in place.  New programs will   continue to move this 
research into operational application mode.  In November, an 
"International Forum on Forecasting El Nino" will be held in Washington, 
D.C.  The forum will launch an International Research Institute for 
climate prediction.

      El Nino, which can occur every two to seven years, originates in 
the tropical Pacific ocean and causes global-scale disruptions in normal 
weather patterns.  When an El Nino   occurs, torrential rainfall and 
flooding is common along the coasts of Ecuador, Peru and southeast Brazil. 
At the same time, Australia, Indonesia, northeast Brazil and southeast 
Africa experience extreme drought and famine conditions.

      The impact of El Nino on the continental United States is less 
direct than in the tropics, but still distinct.  Increased precipitation 
over the Gulf Coast states and warmer   winter temperatures over the 
north-central tier of Gulf Coast states are common, with important 
implications for the agricultural sector of the economy.

     A common indicator of El Nino occurs when the warmest water of the 
global ocean shifts from the International   Dateline in the Pacific 
eastward by 3,100 miles (5,000   kilometers), increasing sea-surface 
temperature by 4 to 7 degrees Fahrenheit (2 to 4 degrees Centigrade).  
This eastward   migration of a heat source critical to the atmosphere 
changes global weather patterns, including precipitation and temperature, 
far beyond the equatorial Pacific.

     Forecasts of El Nino have commonly started with scientists introducing 
ocean-wind data models into a computer model of the ocean, which is then 
used separately to "force" a   model of the atmosphere.  At that point the 
two models are joined, and the likelihood of an El Nino is forecast.  
The new approach mathematically joins the models before introducing the 
data.  Since the real ocean and atmosphere are closely linked, this 
approach yields results that lead to a more accurate forecast.

      "That's the breakthrough," said  Busalacchi.  "This is the first 
time data are being assimilated into a coupled model,  and that's what 
gives us this expanded forecasting capability.  

      "Developing and developed countries are getting this data through 
one-on-one contacts and through NOAA.  They're beginning to use these 
forecasts to adapt to these events and   to mitigate their dangers.  
Advances such as these suggest that it is time to implement a process 
to issue El Nino forecasts on a routine basis, so that the affected 
countries may benefit from this information," Busalacchi said. 

      This kind of computer model, and its use to predict changes in the 
Earth's environment, is the heart of NASA's Mission to Planet Earth and 
the U.S. Global Change Research   Program.  A long-term, coordinated 
research program, Mission to Planet Earth is designed to provide near-term 
benefits.  The program provides improved forecasting of economically 
threatening climate changes such as El Nino, with improved understanding 
of the Earth's climate and how it changes.

       Mission to Planet Earth combines surface measurements and computer 
models with space-based measurements to provide a view of the Earth's 
global environment.  Busalacchi's model, for example, will increase in 
importance when the NASA Scatterometer begins returning worldwide data 
on sea-surface winds.  The instrument is scheduled for launch in August 
1996 aboard a Japanese satellite.

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