Transport in a Dynamic Quadrupole

Lagrangian transport theory has been developed in idealized steady or periodic flows. In recent years these approaches have been applied to realistic ocean general circulation models. These studies have provided important insight into ocean transport, yet little is known about the underlying dynamical mechanisms. Pratt et al. (2014) first addressed this issue in a study of a steady three-dimensional Ekman flow. Here we report on transport mechanisms in a fully three-dimensional, time-dependent dynamically balanced quadrupole. The analysis is based on an exact solution to the linearized Euler equations on an f-plane that includes stratification and captures the roles of vertical motion and vertical shear in transport processes.