On the California undercurrent over the continental slope off Oregon

During July 1975, moored current measurements and a spatially dense approximately isochronal hydrographic survey were made off Oregon. The patterns of geopotential topography, the longshore and onshore‐offshore variations in temperature and salinity, and the current measurements indicated a poleward flow of warmer, more saline water at intermediate depths over the continental slope throughout a longshore distance of about 600 km. The agreement between linear approximations of the north‐south velocity shears determined from baroclinic geostrophic currents and from 3‐day vector‐averaged current measurements was within 3%. The current measurements at intermediate depths indicated a wavelike oscillation, lateral meander, or eddy with a time scale of about 7–10 days, and the surface pattern of the geopotential topography (referred to 1000 dbar) contained eddies or a wavelike feature with a wavelength of about 200 km. Comparison of the time variations of currents recorded simultaneously over the slope and shelf indicated that the subsurface poleward flows observed there were connected.