Radium-226 and Radon-222: Concentration in Atlantic and Pacific Oceans

Science  08 Dec 1967:
Vol. 158, Issue 3806, pp. 1307-1310
DOI: 10.1126/science.158.3806.1307


Measurements of radon-222 in seawater suggest the following. The radium-226 content of surface water in both the Atlantic and Pacific oceans is uniformly close to about 4 x 10-14 gram per liter. The deep Pacific has a concentration of radium-226 that is four times higher and the deep Atlantic a concentration twice as high as that of the surface. These distribution profiles can be explained by the same particle-settling rate for radium-226 from surface to depth for the two oceans and by a threefold longer residence time of water in the deep Pacific than in the deep Atlantic. The vertical distribution of the deficiency of radon-222 in the surface water of the northwest Pacific Ocean suggests a coefficient of vertical eddy diffusion as high as 120 square centimeters per second and a gas-exchange rate for carbon dioxide in surface water between 14 and 60 moles per square meter per year. Vertical profiles of the excess of radon-222 in near-bottom water of the South Atlantic give coefficients of vertical eddy diffusion ranging from 1.5 to more than 50 square centimeters per second.