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Further Outlook
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Can El Nino occur without a preparatory phase, i.e., an El Nino completely different
from those which heve occurred over the last )0 years? There is as yet no definitive snswer.
Recent observations in the equatorial Pacific, from August to Novemberr 1982r euggest that
El Nino ffray even now be occurring. The Climate Analysis Center of the National Oceanic
and Atmospheric Administration in Washington, D.C. has just issued a gecial climate
diagnosis (NOAA, 1982) in which r€ference is made to an abnormal rise in temperature in the
equatorial region of the eastern Pacif ic (Figure ,. This docurnent notes that dlring
September and October of tfris year, global climatic variations were somewhat abnormal. East
and south-east winds in the equatorial Central Pacific heve not only diminishedr but are
bbwing from west to east, i.e., they have changed direction by l80or a phenomenon never
before observed. The sea sJrface Lemperature in the equatorial eastern Pacific has already
reached alarming levels over an area extending nearly to the coasts of Ecuadon end northern
Peru. In addition, two United States scientific vessels, Conrad and Researcher carried out
observations in this area, Conrad in the equatorial central and eastern Pacific from west to
east during Sep[ember and October I98? (Toole, in press), and Researcher in the eastern
Pacific from north to south in November (Hayes, f982). Both vessels rne! with abnormally
warm water along their routes, and found the thermocline at previously unrecorded depthe.
Tlese conditions are without question identical to those which occur during the periods in
which El Nino occurs. ln this circumstance, the answer to our question above would be in the
affirmative, in which case it would be possible to fonecast the non-occurrence of El Nino not
one or two years in advance, but only three to four months in advance, as with forecasts of
its occurrence. The behavior of the winds in the equatorial Pacific during the southern
hemisphere winter should be monitored in order to predict the occurrence or otherwise of EI
Nino.
A definitive answer, however, will have to await lhe results submitted by two Peruvian
scientific vessels, Humboldt and Unanue, currently off the southern and norlhern Peruvian
coast respectively.-tne nforma[i.on provided by scientific and merchant vessels in the
equatorial Pacific, fixed stations along the coasls of Ecuador and Peru, the fixed stations on
the Pacific islands and instrument-carrying buoys in the equatorial region of the eastern
Pacific will also be requ'tred.
Figure ): Anomalies in the surface temperature of the sea in October 1982
(courtesy of ltlOAA)
t20f r00c
) 40 warmer El t-o' warmer