Observing Long-Period Fluctuations of Surface Winds in the Tropical Pacific: Initial Results from Island Data

• DOI: 10.1175/1520-0493(1984)112<0285:olpfos>2.0.co;2
• Publication Date: 2002-07-27T12:21:08Z
• Authors: D. S. Luther; D. E. Harrison
• Keywords: 13. Climate action; 16. Peace & justice

Abstract The utility of studying low-frequency surface weather phenomena with long time series of meteorological data from tropical Pacific islands is demonstrated. The wind stress changes associated with El Nino events in the period 1950–78 are examined at seven locations. Zonal wind stress anomalies at the equator near the date line often exhibit strengthening and subsequent weakening of the trade winds prior to each El Nino, as originally suggested by Wyrtki. An exception is the weak 1963 El Nino, which is preceded by meridional wind stress anomalies at the equator. The strongest zonal and meridional wind stress anomalies, however, occur well after the first occurrence of anomalously warm water off the coast of Peru for each El Nino, in agreement with prior analyses of merchant marine data. Away from the equator, variability of the wind stress anomalies from one El Nino to the next is strong, leading to numerous discrepancies with published profiles of the “mean” El Nino wind changes. Power spectra of ...