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When good rivers turn bad: Extreme flooding
Origins of bad weather

Predicting El Niño

As can be seen from the data presented above, the southern oscillation which creates the El Niño condition has operated throughout the last century. Archeological evidence from South America indicates that the oscillation has been operating for thousands of years. Still, it has only been in recent years that atmospheric and ocean scientists have become aware of the phenomenon, and then only because particularly strong El Niños occurred in the years 1982-83 and 1997-98 causing considerable damage from natural disasters in North America.

The frequency of El Niño events and the intensity of the events is not statistically predictable. In other words we do not as yet know when the next El Niño will occur. This is due to the relatively short amount of historical data currently available. Still, the 1997-98 event and its intensity were predictable several months beforehand because measurements of sea surface temperature from satellites and instrument buoys in the Pacific Ocean were able to identify the movement warm surface waters from east to west across the Pacific Ocean.

Thus, future El Niño events will likely be predictable several months before they actually develop. This could have important economic consequences. For example, knowing that an El Niño event is coming could result in farmers in normally dry parts of South America preparing the soil for a good crop months in advance because of the expected wetter weather in the months ahead. Fishermen could begin preparing for a poor fishing harvest off the coast of South America. In terms of Natural disasters, Peru was much better prepared for the 1997-98 El Niño and constructed storm drains and stockpiled emergency supplies, probably saving thousands of lives.

It is important to remember that because the southern oscillation shifts back and forth, some areas receive beneficial aspects of the phenomenon while other areas receive adverse aspects.

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1. Origins of extreme weather | 2. Finding hidden treasure | 3. Streams and mass wasting
4. The Johnstone River, FNQ


The resources contained in this unit are courtesy of Earth Science Australia http://earthsci.org/