# Star-Convex structures as prototypes of Lagrangian coherent structures

## TL;DR

This paper introduces a new convexity-based method for identifying Lagrangian coherent structures, such as eddy boundaries, in oceanic flows, aiding understanding of ocean transport and climate impacts.

## Contribution

It presents a novel convexity-based approach, with a derived algorithm, for detecting coherent structures in oceanic velocity fields, enhancing existing methods.

## Key findings

- Successfully identified coherent structures in simulations.
- Effectively detected eddy boundaries in real ocean data.
- Method provides clear and interpretable results.

## Abstract

Oceanic surface flows are dominated by finite-time Lagrangian coherent structures that separate regions of qualitatively different dynamical behavior. Among these, eddy boundaries are of particular interest. Their exact identification is crucial for the study of oceanic transport processes and the investigation of impacts on marine life and the climate. Here, we present a novel method purely based on convexity, a condition that is intuitive and well-established, yet not fully explored. We discuss the underlying theory, derive an algorithm that yields comprehensible results and illustrate the presented method by identifying coherent structures and filaments in simulations and real oceanic velocity fields.