ARCTIC OCEAN WATER MASS BALANCE FROM ISOTOPE DATA

The distributions of the oxygen 18 and tritium isotopes, and of salinity, yield a residence time of 10 years for the surface and halocline waters of the Arctic Basin. A yearly net production of 0. 59 m of sea ice and an input of 1. 16 m of freshwater from continental river runoff, local precipitation, and Bering Strait salinity deficiency is found. Using the basin area value with these numbers gives long-term average total net production and transport rates of 0. 15 Sv of ice and 0. 18 Sv of meteoric component, Bering Strait water not included. If, in addition, a reasonable depth profile of relative current velocity is assumed for the outflow, a yearly input of 2. 8 Sv of Atlantic and Bering Strait water is needed to replenish the upper and halocline waters.