Comment on "Evolution of the macondo well blowout: simulating the effects of the circulation and synthetic dispersants on the subsea oil transport".

the Effects of the Circulation and Synthetic Dispersants on the Subsea Oil Transport” P et al. use regional circulation and transport models to simulate the transport of oil from the Macondo well blowout, and conclude that subsurface dispersants may not have been particularly helpful in keeping oil submerged. They reach this conclusion because, without treatment, their assumed droplet sizes were already sufficiently small that much of the oil would have stayed submerged anyway. However this conclusion is based on a model of initial droplet sizes that we do not believe is appropriate. Their characteristic droplet size d (eq S3 in the Supporting Information) comes from Boxall et al. who studied water droplets stirred into oil in a reactor. For droplets larger than the Kolmogorov length scale, Boxall et al. found that standard Weber number scaling applied, or