Temporal evolution of age data under transient pumping conditions.

Highlights: [•] Pumping start is modeled by an immediate shift between two steady-state flow fields. [•] Ages deduced from CFCs and SF6 concentrations evolve in two distinct phases. [•] Transient flow patterns affect ages just after the pumping start but quickly vanish. [•] Atmospheric concentrations then transiently weight the residence time distribution. [•] Similar in terms of magnitude, these two regimes are helpful for models segregation. [Copyright &y& Elsevier]