THE EXISTENCE AND VERTICAL STRUCTURE OF PAST, EASTWARD-MOVING DISTURBANCES IN THE EQUATORIAL TROPOSPHERE

Eastward phase propagation, at speeds faster than 30 m s(-1), of a sig nal in the equatorial troposphere of the Eastern Pacific is detected, first in historical meteorological observations and then in more recen t data. A first baroclinic mode vertical structure is identified with this signal in separate analyses based on linear theory and complex em pirical orthogonal functions, respectively. This rapid, eastward signa l is conceptualized as a far-field dispersion product of strong convec tion associated with the intraseasonal tropical oscillation in the Ind ian Ocean and Western Pacific.