Introduction

Summary

A benefit of the great majority of Lagrangian data being so new is that most of them are available via the Internet. Also, Lagrangian time series analysis may be carried out using conventional time series methods, for which well-supported software libraries abound. Modern dynamical systems theory suggests new and intriguing quantities characterizing the behavior of Lagrangian time series.

Combining Lagrangian data with Lagrangian dynamical models can be conceptually as simple as combining Eulerian data with Eulerian dynamical models, and as complex to implement effectively. Mixing the two formulations of fluid dynamics leads to nonlinearities in the measurement functionals, further complicating effective implementation. Particle pairs make incisive tools for investigating the field of flow: dynamically constrained analysis of float pairs, without having to run all the machinery that is a modern ocean circulation model, is theoretically possible and offers the cability for real-time, even onboard analysis.