Fig. 2 presents the temporal evolution of temperature, salinity, density, tritium, He-3, the tritium/He-3 age, CFC 11, and CFC 12 as time-depth sections throughout the entire water column. The frequency of cruises to the Greenland Sea varied over time, as did the number of stations occupied during the individual years. The data used to produce Fig. 2 were gridded with a time step of three months and a depth interval of 25m. The depth intervals and time periods without observations were linearly interpolated. Finally, the interpolated fields were smoothed by averaging each point with its eight closest data points.