USING RANDOM-WALK MODELS TO SIMULATE THE VERTICAL-DISTRIBUTION OF PARTICLES IN A TURBULENT WATER COLUMN

Random walk simulation has the potential to be an extremely powerful t ool in the investigation of turbulence in environmental processes. How ever, care must be taken in applying such simulations to the motion of particles in turbulent marine systems where turbulent diffusivity is commonly spatially non-uniform. The problems associated with this nonu niformity are far from negligible and have been recognised for quite s ome time. However, incorrect implementations continue to appear in the Literature. In this note computer simulations are presented to illust rate how and why these implementations are incorrect, and a simple tec hnique that can properly simulate turbulent diffusion in the marine en vironment is discussed.