Removing tides from ship-mounted ADCP data, with application to the Yellow Sea

A simple method developed to approximate the spatial structure of the tide over a given region surveyed by a ship equipped with an acoustic Doppler current profiler is described. This approach permits the subsequent elimination of the tide-induced variability from the ADCP data to yield the residual flow. The method used is a spatial interpolation scheme that allows for the tidal current time variability. Two functions are investigated as possible basis functions on which to expand the tidal and residual current spatial structure. based on their flexibility and their behavior in and at the edges of the interpolating region. This method is applied to ADCP data acquired in January 1986 in the Yellow Sea over the domain 30°-37° N, 120°-128° E