The 1987 Reciprocal Tomography Experiment (RTE87): Barotropic Current Data from the Triangular Tomographic Array

Ocean acoustic tomography was tested in 1987 with a O(1000-km) scale triangular array in the central North Pacific. The 1987 Reciprocal Tomography Experiment (RTE87) used reciprocal acoustic transmissions along the acoustic paths to test the ability of tomography to measure both temperature and current. It quickly developed that the difference of the reciprocal ray travel times provided an excellent measure of barotropic currents. In particular, tidal barotropic currents, the dominant signal of the ray travel time time series, were measured to remarkable accuracy. This publication makes available the tomographic estimates for barotropic currents derived from the thee paths of the RTE87 tomography array. The array was also used to detect the coherent radiation of mode-1 internal tides from the Hawaiian Ridge, 2000 km to the south; these data are available separately.