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During the Geosecs expedition in the Atlantic and the Pacific oceans, more than 100 stations were occupied for the measurement of surface radon profiles. The radon deficiency in these profiles gives estimates of the gas transfer rate across the sea‐air interface. The global mean transfer rate is estimated to be 2.9 m/d (at 20°C) which is corresponding to a hypothetical stagnant film thickness of about 36 microns. No clear relationship can be found between the gas exchange rate and wind speed. The CO2 exchange rate as determined by the radon method is 80% of that given by the distributions of natural and of bomb‐produced radiocarbon. One possible explanation may be that the Geosecs radon measurements were made during periods of lower than average wind speed. Another is that the conversion of CO2 to HCO3− is catalyzed within the sea.

The Antarctic Convergence forms a distinct boundary for surface radium distribution. To the south of the convergence radium concentrations near the surface are close to 8×10−14 g/l and those of the deep waters, 10×10−14 g/l. To the north surface concentrations drop to 4×10−14 g/l, whereas bottom values remain near 10×10−14 g/l, the transition being at a depth below 500 meters. Radium distribution in this part of the ocean strongly reflects the influence of advection and water‐mass movement. Also, downward transport of radium through particle settling is clearly demonstrated. The nature of the radium‐bearing particles in the ocean may be closely related to siliceous organisms.

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