Batchelor scale for typical marine turbulence levels

Range 30-300 µm
Organism Unspecified
Reference Stocker R. Marine microbes see a sea of gradients. Science. 2012 Nov 2 338(6107):628-33. doi: 10.1126/science.1208929. p.628 right column 4th paragraph & p.630 box 1PubMed ID23118182
Primary Source G. K. Batchelor, Small-scale variation of convected quantities like temperature in turbulent fluid Part 1. General discussion and the case of small conductivity, J. Fluid Mech. 5, 113 (1959). DOI: link
Comments Box 1:"The shape of a solute patch is affected by two transport processes: diffusion and turbulence. Turbulence stirs the patch into ever-finer filaments. As a filament thins, the associated gradient (the concentration contrast with the background, divided by the filament width) grows. This increases the effect of diffusion, which is proportional to the magnitude of the gradient, in erasing the gradient. There is, hence, a scale where the effects of turbulence and diffusion balance. This scale is the Batchelor scale (primary source), (?D^2/?)^(1/4), which in the sea ranges from 30 to 300µm depending on the turbulent dissipation rate ?, the diffusivity of the solute D, and the kinematic viscosity of seawater, ?."
Entered by Uri M
ID 110357