Dynamics of inertial and non-inertial particles in geophysical flows

We consider the dynamics of inertial and non-inertial particles in a single-layer, quasi-geostrophic (QG) ocean model. We investigate the underlying structures of the flow field by examining their Lagrangian coherent structures (LCS) which are found by computing finite-time Lyapunov exponents (FTLE). We study the behavior of massless non-inertial particles using the fluid velocity fields from the QG model and compare it with the behavior of massless inertial particles in a double-gyre model, duffing oscillator, and bickley jet. For inertial particles with finite size and mass, we use the Maxey-Riley equation to describe the particle's motion, and compare the particles' behavior in a double-gyre flow, duffing oscillator, and bickley jet. We explore the preferential aggregation of inertial particles and demonstrate how particle clustering depends on the density ratio and the Stokes number.