Tritium in the Equatorial Atlantic Current System

An improved sampling and analytical technique for ultra-low specific activities of tritium, as HTO, in sea water, is described. Tritium data, together with salinity and temperature from the Equalant III expedition in 1964 are presented and discussed. Negligible penetration of HTO below the thermocline is found in this area. Tritium-salinity relations support the concept that molecular exchange constitutes a major portion of the air to sea flux of HTO. A time scale of a few years seems reasonable for the transfer of distant surface water to the salinity and current cores of the Equatorial Atlantic Undercurrent.