VENTILATION OF NORTH PACIFIC INTERMEDIATE WATERS - THE ROLE OF THE ALASKAN GYRE

Hydrographic data, tritium data, and potential vorticity calculations suggest that although North Pacific Intermediate Water is formed in the northwest, the Alaskan Gyre might be an additional ventilation site. The proposed ventilation is quantified by a vertical column tritium inventory, which indicates an excess of 0.08 kg of tritium in the Alaskan Gyre. An evaluation of the energy stored in the water column and of wind and buoyancy forcing shows that during winter conditions enough energy can be pumped into the system to force 26.80-sigma-theta to outcrop in the Alaskan Gyre. Model results suggest that relatively limited outcrops in time and space (ten of days and several hundred kilometers in diameter) can account for the excess tritium.