In the oceans of the world there are four major upwelling zones, two in the Pacific and two in the Atlantic. These currents bring nutrients to the uppermost layers of the ocean where photosynthesising photoplankton, photic zone dwellers and large numbers of fish live. Every few years however the currents that exist in the Eastern Pacific are distorted by what is known as El Nino, Southern Oscillation. Currents reverse direction, hot air rises earlier as it travels across the ocean and the atmosphere in the area has a higher water current. The El Nino is much more complicated than just that but it has results that are thought to affect the world. These affects are called Teleconnections.
Before one can look at what Teleconnections are, it has been discussed that they may not even exist. The uncertainty of climatic change is so large that when events are "statistically" liked the mathematics behind the connection may not be enough to feasibly deduce that the events are connected.
In general the climate of our Earth is incredibly variable. Natural variations may account for many natural disasters that are linked to El Nino. Lorenz (1968) raised a fundamental question: Is our climate stable? Non linear systems, which are far simpler than the atmosphere sometimes display a tendency to fluctuate in an irregular manner. *1 It has been suggested that the same may occur with our atmosphere. On the other hand, on the assumption that climatic changes are more than just random fluctuations, paleoclimatologists have sought evidence of regularities in some climatic changes e.g., global ice levels across the Earth in the last 700, 000 years seem to summarises in a 100,000 year cycle. *2
There is today, inadequate understanding of the climate and particular events especially when it comes to linking events. Without knowledge of how incidents are formed transpire, it is understandable that we can not fully blame one occurrence on another. Events can only be assigned probabilities of occurrence rather than a definite 'will' or 'will not' happen. There are not suffiecent recording facilities across the world to make accurate predictions. The numbers of facilities are sufficient but the distribution is not. Bias becomes a factor in recording data. There is a lack of information about climatic events from area of ocean and over the ice caps. Satellites are now helping us acquire more data but it will take time to record enough data to make accurate predictions and even longer to summarise and interpret all the figures. Finally, there are certain factors that affect the earth's climate that can not be predicted, to any level of satisfaction, that may well alter El Nino and affect any Teleconnections that may exist. An example of these occurrences is a volcanic eruption that will change atmospheric content on a scale large enough to offset global warming for substantial lengths of time. These eruptions make it difficult to predict and link other events occurring on the earth's surface at the same time with any accuracy. But it has been assumed that Teleconnections do exist and some study has been done about them. Teleconnections will exist in El Nino years and non El Nino years due to the fact that some climatic change is not immediate and certain occurrences takes years to evolve. Statistical evidence can account at most for about 50% of the interannual rainfall variance in Eastern and Southern Africa (Ogallo, 1994), but many of the extreme anomalies such as severe droughts, flooding and hurricanes have strong Teleconnections to El Nino. Understanding these connections can help in the prediction of many natural disasters and therefore save lives and money. There has been large amounts of study into the affects of the 1982/3 El Nino which is one of the strongest and largest climatic events recorded. _„ Virtually every continent was affected in one way or another by the Teleconnections. There follows a table of estimated affects of the 1982/3 El Nino. The effects are not just centred on the Pacific areas that are normally affected by the Southern Oscillation but most continents are involved.
| Location | Climatic Change | Death Toll | Economic cost ($) |
| US mouintain and Pacific States | Storms | 45 | 1.1billion |
| US Gulf states | Flooding | 50 | 1.1billion |
| Hawaii | Hurricane | 1 | 230million |
| Northeastern US | Storms | 66 | n/a |
| Cuba | Flooding | 15 | 170million |
| Mexico & Central America | Drought | n/a | 600million |
| Equador and N. Peru | Flooding | 600 | 650million |
| S.Peru & W.Bolivia | Drought | n/a | 240million |
| S.Brazil & N.Argentina | Flooding | 70 | 3.0billion |
| Bolivia | Flooding | 50 dead & 60,000 homeless | 300million |
| Tahiti | Hurricane | 1 | 50million |
| Australia | Drought & Fires | 71 | 2.5billion |
| Indonesia | Drought | 340 | 500million |
| Philippines | Drought | n/a | 450million |
| S.China | Wet Weather | 600 | 600million |
| S.India & Sri Lanka | Drought | n/a | 150million |
| Middle East | Cold, Snow | 65 | 50million |
| Southern Africa | Drought & Starvation | n/a | 1.0billion |
| Iberian Peninsula | Drought | n/a | 200million |
| N.Africa &W.Europe | Flooding | 25 | 200million |
If we can understand some of the above Teleconnections we could
hopefully be able to start predicting them in advance saving lives
and money. Computers can come in useful in this type of prediction
and any advances we make in statistical and physical modeling
will be of use in other areas. Peru is an example of country that
would benefit from El Nino and Teleconnections predictions and
understanding. It is a developing country in the tropics where
climate and subsequently food production is highly sensitive to
climate change. Yearly fluctuations in sea surface temperature
are unfavourable to the fishing industry and flooding in the Andean
foothills ruin vast amounts of crops annually. Cold years are
therefore welcomed by fishermen but disliked by farmers. The cold
years tend to come the year after the El Nino event so Peruvians
need to be aware of the Southern Oscillation, not only during
the event but after it as well. After the 1982/3 El Nino the task
of the Peruvians was to predict the climate or the coming year.
In November 19 _-83 the conditions of sea temperature has returned
to near normal and therefore the rainy season preferable for crop
growing was about to return. The forecast was correct and the
resulting harvest was very productive. Since this example of El
Nino and Teleconnections prediction in Peru the Peruvian authorities
have set up a prediction service based on observations of winds
and water temperatures in the Tropical Pacific region, the prediction
being made up of four stages. 1. Normal Conditions, 2. A weak
El Nino with a slightly wetter than normal growing season, 3.
A full blown El Nino with flooding, and 4. cooler than normal
offshore waters with a higher than normal chance of drought.During
the past forty years, nine El Ninos have affected the South American
Coast, each one possibly having affect on other locations in the
globe with unstudied and little understood affects.
This page lists the social and economic affects of El Nino on certain areas in the US including Agriculture, climate, precipitation, tornadoes, snow etc.
The NDMC helps people and institutions develop and implement measures to reduce social vunerability to drought, which in some cases has been linked to El Nino.