An extensive study of surface currents off northern Baja California, using parachute drogues, has confirmed the inshore sweep of surface waters that has been a major feature of the geostrophic flow in this area. Calculations of geostrophic flow from concurrent density measurements are in excellent agreement with the drogue trajectories, and an extra hydrographic cast made at the center of an eddy that was indicated earlier by the drogue movements confirms the remarkable small-scale coherence of the density and velocity fields....
Reid, Joseph L., Richard A. Schwartzlose, and Daniel M. Brown. 1963. "Direct measurements of a small surface eddy of northern Baja Califirnia." Journal of Marine Research 21, (3). https://elischolar.library.yale.edu/journal_of_marine_research/1008