El Niño Cometh ... or Doth It?

May 28, 1997
By Michael Glantz

Fragilecologies By Michael GlantzThe waters are warming up, the westward-blowing winds are slackening, the fish are changing their normal patterns. All this is currently happening in the Pacific Ocean, along the equator. Scientists who monitor these sorts of things believe that an El Niño event is emerging. If that is true, science writers and environment reporters will be dusting off their pens, and the public will be bombarded with new stories about El Niño and its impacts on environment and people in various parts of the globe.

El Niño is the appearance of warm surface water in the central and eastern equatorial Pacific Ocean off the coast of Peru and Ecuador. The return of El Niño happens, on average, roughly every four to seven years, and they tend to last between 12 and 18 months. However, there have been times when none have occurred during that period of time and other times when they have seemingly lasted for more than a few years, such as in the early 1990s.

For much of this century scientists, among others, thought that El Niño was a local phenomenon affecting only the Peruvian coastal waters by, for example, having a negative effect on fish along the coast and on fish-eating, guano-producing birds. Guano birds are pelicans and cormorants which eat the fish that swim near the ocean's surface; the birds then deposit their droppings on rocky islands and along the rocky coast. The droppings were identified in the early 1800s as having considerable value as a fertilizer for agricultural production. They were mined and, in the early 1900s, Peru created the Guano Administration Company to monitor mining activities and to protect the bird colonies from predators.

Before scientists started to pay attention to El Niño, one sign to local people that an event was in progress was the appearance of thousands of dead birds along the Peruvian shore. When an El Niño is coming, warm water covers over the cold water that normally comes up to the surface; the cold water is rich in nutrients which serve as food for fish. With the disappearance of the fish that feed in the cold coastal waters, the birds do not eat, so they grow weak and fall into the sea.

Later, after Peru developed a fishing industry, interest in El Niño centered around the fact that it was blamed for the collapse of Peru's fishing industry in the early 1970s. It was after the major event of 1982-83 that interest in El Niño's impact on weather events around the world developed. It was the largest El Niño event in a hundred years and was so big that its impacts around the globe were easy for everyone to see: droughts throughout most of Africa, Australia, Central America, the Soviet Union, Southern Africa, and northeast Brazil; flooding in Kenya; cyclones in the Pacific; and so on. The impacts were so devastating and widespread that popular magazines such as National Geographic and Reader's Digest ran stories on the phenomenon.

An El Niño can be a big event or a small one, depending on several things: how warm the ocean's surface waters get, how large an area of the equatorial Pacific warms up, and how much damage it causes around the globe.

The most recent reports on the possibility of an upcoming El Niño are now arriving from NOAA's Climate Prediction Center and from the Peruvian Sea Institute. The scientific community is all abuzz about the possibility of another El Niño. They see it as an experiment that is carried out by Nature every few years or so. They get to forecast it, observe it, analyze it, and generate new ideas about what causes it and about what its impacts might be.

El Niño s worldwide impacts are referred to as teleconnections, or the connections between the warming of sea surface waters in the Pacific and weather around the globe (from the Greek prefix tele, meaning "at a distance"). Its impacts are strongest from Latin America across the Pacific and the Indian Ocean and to the African continent. It also affects weather patterns outside the tropics.

Researchers are trying to identify El Niño's impacts on North America. Some people believe that during an El Niño event, winter in the Pacific Northwest will be warm and dry, winter in the Northeast US will be mild and wet, and winter in the southeastern US will be wet and cool. However, its impacts on the Rocky Mountain West and California remain unclear.

This El Niño gives us another opportunity to think about how El Niño might affect us over the next year or so, assuming that an event actually does occur.

Having just published a book on El Niño (Currents of Change) I had not planned to write about it again for some time to come. However, early warnings of an El Niño event at this point in time can be used to alert you to the barrage of El Niño-related stories that will appear in the media in future months.

The discussion of El Niño in high school science books is minimal at best. Yet, after the natural flow of the seasons from spring to summer to fall to winter, El Niño is perhaps the next major force affecting our weather patterns from year to year.

If forewarned, the reader can track new stories as they develop over time. Upcoming TV and newspaper stories will most likely proceed from an initial focus on the science of El Niño and forecasting it to a focus on the damaging impacts that are sure to follow. Here s a chance to get ahead of the media and to use this developing event as a "virtual" classroom experience.

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