Ed:

Peter Niiler, an oceanographer of international repute working from Scripps, has spent the last twenty years building a network of drifter buouys which collect and transmit data on ocean currents. The drifters have built up a vast wealth of data points over the years from which Niiler was able -- with some additional satellite observations and some very advanced math--work out the existence of what has come to be know as Niiler striations in the current formations of the major oceans. See this page at Scripps and this piece. More on the Niiler drifter program.