Abstract
Synoptic maps of the mesoscale dynamic topography in a band between 7.5°N and 7.5°S in the Pacific Ocean are drawn from Seasat altimeter data. They show a set of eddies 600 km in diameter and 15–20 cm in amplitude moving westward with a velocity of about 40 km day−1 along 4.5°N. Their occurrence is consistent with the surface temperature front undulations observed by Legeckis. South of the equator the signal is less coherent, but a significant degree of symmetry with the north is evidenced. The dynamics of the wave system might also present some degree of nonlinearity, as some water seems to be carried along with the wave.