Dynamics of Inertial and Non-Inertial Particles in Geophysical Flows

We consider the dynamics of inertial and non-inertial particles in various flows. We investigate the underlying structures of the flow field by examining their Lagrangian coherent structures (LCS), which are found by computing finitetime Lyapunov exponents (FTLE). We compare the behavior of massless noninertial particles using the velocity fields from four models, the Duffing oscillator, the Bickley jet, the double-gyre flow, and a quasi-geostrophic geophysical flow model, with that of inertial particles. For inertial particles with finite size and mass, we use the Maxey-Riley equation to describe the particle’s motion. We explore the preferential aggregation of inertial particles and demonstrate how particle clustering depends on the density ratio, the Stokes number, and the particle size. We also study the e↵ect of the Fax´en correction and an often used assumption whereby the material derivative is set equal to the total derivative