Where is El Niño?

Abstract

I enjoyed George Philander's note, “Who is El Niño?,” (Eos, March 31, 1998, p. 170) and his effort to rationalize the Nino nomenclature. There is a further complication that he does not mention—the widespread labeling of El Niño as any unusual warming far from the equator, whether or not it is linked to the tropical event. This leads to considerable confusion, since the timings and intensities of these occurrences may be very different. For example, El Niño of 1972–1973 was a major event in the tropics that was associated with the collapse of the Peruvian anchoveta fishery, and yet significant sea‐surface temperature anomalies were barely detectable north of southern California. No one on the Washington coast would have called this El Niño. On the other hand, the minor tropical event of 1976–1977 was associated with the regime shift in the eastern North Pacificsemi; unusual surface warming as far north as the Bering Sea persisted into the early 1980s. Should both the 10‐month tropical event and the 5‐year subarctic event be called El Niño? The current frenzy over the 1997–1998 event, where subarctic warming was contemporaneous with equatorial developments, demonstrates the need to regularize the terminology.