Fast, eastward-moving disturbances in the surface winds of the equatorial Pacific

A fast, eastward signal in the surface zonal winds of the equatorial Pacific ocean is identified in ERS-1 data that coincide with an intraseasonal tropical oscillation during the intensive observing period of TOGA COARE. The fast eastward event is compared with observations for the same time period from the TAO moorings at the equator. Similar events are identified in longer records of the ERS-1 and TAO data. A composite event is constructed and a lagcorrelation analysis is used to infer basin-scale propagation speed. The fast eastward events in the ERS-1 data are consistent with signals in station surface pressure and station profile data quantified by Milliff and Madden and connected with first-baroclinic mode equatorial Kelvin wave propagation.