This year, El Nino has been blamed for severe storms, droughts and other extreme weather related phenomena around the world. What is El Nino, anyway, and what causes it? I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.
“The name El Nino comes from Peruvian fisherman.”
Steven Anderson is an assistant scientist in the department of Oceanography at Woods Hole Oceanographic Institution.
“The coast of Peru is known for strong winds blowing along the coast that drives an ocean circulation which brings cold nutrient waters to the surface. These nutrients feed the plankton which in turn feed the fish. So it’s very good fishing there. Well the Peruvian fishermen found that every couple of years those surface waters would warm up and the winds would die down and the fish would all go away because there’s no longer any nutrients for them. This reached its maximum during Christmas time and they used the term El Nino for the child or Christ to give this phenomenon a name. In a typical year the trade winds along the equator are blowing from the east towards the Western Pacific. The Western Pacific has the highest sea surface temperatures along the equator in a region called the warm pool.
During an El Nino year, the warm pool moves from the Western Pacific near Indonesia, eastward towards the International Dateline. And associated with this shift in the warm pool location is a slackening of the trade winds and a shift in large scale circulation patterns in the atmosphere.”
And it’s these large scale circulation patterns that can effect weather all over the world.
Pulse of the Planet is presented by the American Museum of Natural History. I’m Jim Metzner.