ABSTRACT

The exchange rate of oxygen across the air-sea interface has been determined from the dissolved oxygen content of sea water in the Funka Bay by applying a closed system model to the Bay water. The change in dissolved oxygen resulting from the biological processes has been evaluated by the change in phosphate. The observations during the period from 1973 to 1980 show a marked seasonal variation in the exchange constants. The mean thickness of the surface film or the molecular diffusion layer at the interface calculated from the exchange constants is 12μm in winter, whereas that is 45μm in summer. Both values are greater than those obtained from laboratory experiments and the field observations of radon profiles, but nearly equal to the value calculated from the mean residence time of carbon dioxide in the atmosphere. The seasonal variation is due to the roughness of the sea surface, suggesting that the exchange constant seems to be proportional to the square or the cube of wind velocity. The Bay is a source of oxygen to the atmosphere, where the net production of oxygen is found to be 1701/m²/yr.