Title: CURRENTS AND WATER MASSES AT THE ENTRANCE TO THE GULF OF CAUFORNI Abstract approved:

Hydrographic data and drogue observations were used to des-cribe thecirculation and water masses in the upper 500 meters of the region of the entrance to the Gulf of California in the early spring of 1970. The thermohaline structure of the water and the general circu-lation in the vicinity of the entrance to the Gulf of California indicated that four water masses were present. California Current water on the western side of the entrance, Subtropical Surface water in the middle part and Gulf water on the eastern side. Underlying these three waters, Subtropical Subsurface water was found from about 150 to 500 meters. The geostrophic calculations indicate that a broad region of outflow from the Gulf existed on the eastern side associated with a marked upward displacement of isopycnals towards the east. Redacted for privac