Modelling Turbulent Dispersion of Buoyancy Regulating Cyanobacteria in Wind-Driven Currents

Vertical movement of buoyancy regulating cyanobacteria in wind-driven currents was simulated based on Lagrangian approach and a validated buoyancy regulation model. Turbulence of water was simulated using k-epsiv model. Effects of a range of wind speeds on cyanobacteria colonies of different sizes were discussed. Dispersion of colonies intensified as wind speed increased. Small colonies tended to mixing in turbulent environments and even staying at the bottom of water, instead of accumulating at the water surface. For dispersing larger colonies, higher wind speed that produced more intensive turbulence was required. During the night, turbulence might prevent water-bloom, but in the day, turbulence could increase the percentage of colonies at the surface.