Ocean Science www.ocean-sci.net 1812-0784 1812-0792 3 4 2007 10.5194/os-3-525-2007 http://www.ocean-sci.net/3/525/2007/ http://www.ocean-sci.net/3/525/2007/os-3-525-2007.html http://www.ocean-sci.net/3/525/2007/os-3-525-2007.pdf 525 535 2007-12-20 The backward Îto method for the Lagrangian simulation of transport processes with large space variations of the diffusivity D. Spivakovskaya d.spivakovskaya@ewi.tudelft.nl A. W. Heemink E. Deleersnijder Department of Mathematical Physics, Delft Institute of Applied Mathematics (DIAM), Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands Université catholique de Louvain, G. Lemaitre Institute of Astronomy and Geophysics (ASTR) & Centre for Systems Engineering and Applied Mechanics (CESAME), Avenue G. Lemaitre 4, 1348 Louvain-la-Neuve, Belgium Random walk models are a powerful tool for the investigation of transport processes in turbulent flows. 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