The return of El Nino
In its strictest sense, El Nino is the warming of the seas in the Pacific. Its counterpart is La Nina, a cooling of the same region.
They arise as a result of the Southern Oscillation, a see-sawing of pressure and wind between high pressure over the eastern South Pacific and low pressure centred near Indonesia.
Although the direct result of El Nino-La Nina is a change in ocean temperatures which have a dramatic effect on fish and bird life, the knock-on effect on weather patterns has a great impact on human activities around the globe.
The latest organization to predict its return is Australia’s Bureau of Meteorology. On Tuesday the Bureau said that there was a 70 percent chance of an El Nino, with its emergence predicted to be as early as July.
Meanwhile, Dr Wenju Cai, a climate expert at Australia’s Commonwealth Scientific and Industrial Research Organisation claims that a 6 deg C rise in Pacific Ocean temperatures in recent months, well in excess of previous El Nino years, and the rapid eastward movement of water in the Pacific, point towards a significant event.
“A strong El Nino appears early and we have seen this event over the last couple of months, which is unusual; the wind that has caused the warming is quite large and there is what we call the pre-conditioned effects, where you must have a lot of heat already in the system to have a big El Nino event.”
His conclusions are based on data released by the US National Oceanic and Atmospheric Administration.
The last major El Nino was in 1997-8. It was blamed for the flooding along the Yangtze River in China, which killed more than 1,500 people.
Globally, the economic cost of this event was calculated at $35 to $45 billion, largely as a result of its impact on the agriculture and fishing industries.
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