Gas Bubbles as Oceanographic Tracers

Baschek, B. and D.M. Farmer

J. Atmos. Oceanic Tech., 27, 1, p. 241-245, 2010.

Air bubbles can be used as oceanographic tracers that indicate the strength of a downwelling current by which they are subducted. In a tidal front in the Fraser Estuary, British Columbia, Canada, vertical currents of up to 0.70 m s-1 subduct bubbles to depths of more than 160 m. Echo sounder measurements are compared with simultaneous ADCP current measurements and are interpreted with a bubble model by Thorpe (1982), yielding an estimate of the vertical current that carry the bubbles to the depth of measurement.