Multiscale Modelling of the Turbulence Induced Biodynamical Interaction (TIBI) Effect

In the late 1990s Allan Robinson developed a theory of NPZD interactions in a laminar upwelling flow field. His approach was to use the advection reaction (AR) equation in a Lagrangian coordinate system. Recently, and prior to his untimely death, he and I extended and generalized this theory to include a variety of types of ocean turbulent regimes. We showed that, in general, the Turbulent Induced Biodynamical Interaction (TIBI) could not be neglected. The TIBI effect is associated with turbulence inducing fluctuations in nonlinear biological constituent interactions and is separate from the effect of turbulent mixing in dispersing the constituents. In this new work several types of ocean turbulence spectral models are employed to examine the role of multi scale fluctuations on the TIBI effect. Results from models of both microstructure and “submesoscale” turbulence will be presented. This will be contrasted with using the standard single scale random walk model of turbulence, which has been shown , in general, to underestimate the magnitude of the TIBI effect.