FY 1976

Observations of the California Undercurrent off Washington and Vancouver Island

Reed, R.K., and D. Halpern

Limnol. Oceanogr., 21(3), 389–398 (1976)

A detailed oceanographic survey was conducted in the Pacific off the coast of Washington and Vancouver Island in September 1973, and 12-h time-series measurements were made at eight sites. Data from the time-series stations suggest the presence of semidiurnal internal tidal waves seaward of the continental shelf. The resulting disturbances to the geopotential anomalies, however, had little effect on the derived patterns of geostrophic flow. During this survey, the surface flow relative to 1,000 db was generally southward, but a northward flow was present at intermediate depths along the continental slope. This northward flow appears to be an extension of the California Undercurrent, which remains an identifiable feature to at least 49°N but weakens along its path by mixing with adjacent water. An additional northward flow in the northern part of the area resulted from a cyclonic eddylike feature.