Linear barotropic waves in the tropical atmosphere and on the equatorian-columbian coast. Using time series of daily averages of atmospheric pressure, environmental temperature, superficial temperature and mean sea level during 1994-1995 in five stations from Ecuador, Colombia and one station in the Galápagos Islands (Ecuador) techniques of spectral analysis were applied in order to determine the existent oscillations in the ocean and the atmosphere. They were given two predominant modes in the tropical atmosphere: the oscillation of 37 days with hight levels of coherence, very close to the oscillation of Madden and Julian (1972) and a second oscillation of 17 days with high coherence, of characteristic very similar to the Kelvin Equatorial wave detected in the central Pacific (Wunsh and Gill, 1976). In the ocean were detected: a mode of 14.7 days with hight coherence and great energy in the spectra associated to the biweekly moon component. Finally an oscillation of 9 days, that suggests characteristic of a Kelvin equatorial wave of the first baroclinic mode of 9 days very similar to waves mentioned by Wallace (1971). The presence of oscillations were detected with periods of 30, 18, 5 and 10 days in the spectra of superficial temperature of the sea that could have nature of internal waves. The most predominant seasonal waves were characterised, showing highter energy in the humid season.