Population Dynamics in Two-Dimensional Compressible Turbulence*

The dynamics and genetics of populations of microorganisms in marine environments is a fascinating scientific topic at the crossroads of biology, statistical physics and fluid dynamics.
In realistic settings, for a population living in a fluid environment, it is largely unknown, how the phenomenology of a dynamic population is changed by the presence of turbulence. Effective compressibility can arise when passively traveling organisms living at a specific depth experience the convergence or divergence of water masses. The flow can significantly diminish the effect of selective advantage on fixation probabilities. However, because of number fluctuations a relatively small selective advantage may not be successful since the characteristic time scale is much smaller than the one associated to turbulent effects. This project, focuses on the enhancement or suppression of selective advantage in PD subject to advection of two dimensional compressible turbulence. We implemented a two dimensional code particularly suited to investigate a large number of particles.