GAS TRANSFER EXPERIMENT ON GEORGES BANK USING 2 VOLATILE DELIBERATE TRACERS

A gas exchange experiment was performed on Georges Bank using delibera te tracers sulfur hexafluoride (SF6) and helium 3(He-3). The concentra tions of the tracers were measured in the water column over a period o f 10 days. During this time the patch grew from an 8-km-long injection streak to an area of about 500 km2. The ps transfer velocity was dete rmined from the change in the ratio of the tracers over time scaled to the ratio of their Schmidt numbers. A near-linear relationship betwee n gas exchange and wind speed was observed based on four experimental points covering a wind speed range from 3 to 11 m/s. The results fall in the upper part of the range of gas transfer-wind speed relationship s developed to date. Wind speeds during the experiment obtained from a nemometers on the ship, on a free floating drifter, and on a fixed moo ring showed significant differences. With the ability to measure gas t ransfer velocities over the ocean on timescales of several days, accur ate wind speed/stress measurements are imperative to obtain a robust r elationship between gas transfer and wind speed.