Parameterization of drag and dissolution of rising CO 2 drops in seawater

In this work the dynamics and dissolution of a hydrate‐covered CO 2 drop were studied, using a numeric model and data from one of very few CO 2 experiments performed in the real ocean. A theory including the standard drag curve of rigid spheres was shown not to fit the observed drop rise velocity. However, a drag parameterization supported by numerous laboratory experiments with gas bubbles provides a good match of the observed rise velocity of a liquid CO 2 drop covered with hydrate. The results confirm laboratory results showing that shape is a key factor determining the CO 2 drop dynamics. We also found that hydrate reduces the mass transfer of the observed drop by a factor of 2, which is compatible with laboratory experiments. Numerical experiments with different drop sizes showed that the choice of drag parameterization has a significant impact on the estimated vertical distribution of dissolved CO 2 .