Gerald McCormack, CINHT
During the summer of 1982-83 Rarotonga experienced a severe drought. Although some water continued to flow into the mains, there was only enough for those near the source – remote areas, like Nikao and Arorangi, were lucky to have a trickle after midnight when the upstream users were asleep. In some areas trucks filled temporary tanks in the streets, and householders carried it in buckets into their homes.
As the drought progressed we learnt that many other parts of the world were also having unusual weather – droughts in some places, torrential rain in others. We were also told that the cause was something called El Niño. Apparently about a hundred years ago Peruvian fishermen noticed that the arrival of a warm ocean current around Christmas was the first indication of a disastrous fishing season, and widespread heavy rain causing landslides and floods. Because of its arrival time they called it the “current of the (Christ) Child”. Gradually the current and the associated weather became known as El Niño, variously translated as “the Christ child”, “the Child”, or “the little Boy”.
After the extreme 1982-83 event scientists became very active in seeking to explain and predict such irregular weather events. As a result the term El Niño was soon joined by others: Southern Oscillation (SO), Southern Oscillation Index (SOI), ENSO (El Niño and Southern Oscillation), and Warm Event. More recently we have learnt that after an El Niño the weather may overshoot “normal” and go to the opposite extreme. This “opposite of El Niño” is a La Niña (“the girl child”) – or a Cold Event, because conditions off Peru are colder than usual. Continue reading →
