ABSTRACT
On the 26.5 isopycnal level, we observe tritium concentrations in the South (Stations 12, 6, 2) higher than the corresponding tritium content of the surface waters. On figure 1, we can observe that the wintertime outcrop of this isopycnal takes place North of the Azores front : the tritium enrichment of the Southern stations on the 26.5 sigma-theta level is the result of the transport of tritium enriched waters from an area located to the north of 35°N by the anticyclonic gyre. On the same isopycnal, we observe for the station 33 and 36 relatively low tritium concentrations (Figure 3) correlated with negative 63He values (Figure 2) suggesting a remainder of surface convection. On the 26.5 isopycnal level these stations are more imprinted by the 18°C Mode Water than by the anticyclonic gyre. In the North we observe everywhere negative 63He values as the result of recent convection.
