SOLITARY WAVES IN THE WESTERN EQUATORIAL PACIFIC-OCEAN

During the spring tides of early January and February 1993, groups of solitary internal waves were observed propagating through the Intensiv e Flux Array of the TOGA COARE experiment. The waves appear to origina te near the islands of Nugarba (3 degrees S 30'S - 154 degrees 30'E). They travel north-eastward at 2.5-3 m/s, closely coupled with the semi -diurnal baroclinic tide. Peak amplitudes exceed 60 m. Velocities are in excess of .8 m/s. Sea-surface vertical displacements of order .3 m can be inferred directly from the lateral acceleration of surface wate rs. The Equatorial Undercurrent is displaced by soliton passage but ap parently is unaffected otherwise. The intrinsic shear of the solitary crests is small compared to ambient equatorial shears. The crests, whi le not themselves unstable, are effective at triggering instabilities on the background flow. The motions potentially contribute 10-15 Watts /m(2) to the flux of heat into the mixed layer.