Uncertainties in the finite-time Lyapunov exponent in an ocean ensemble prediction model

Matuszak, Mateusz; Röhrs, Johannes; Isachsen, Pål Erik; Idžanović, Martina

doi:https://doi.org/10.5194/os-21-401-2025

Articles | Volume 21, issue 1

https://doi.org/10.5194/os-21-401-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/os-21-401-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 21, issue 1

Research article

|

12 Feb 2025

Research article |

| 12 Feb 2025

Uncertainties in the finite-time Lyapunov exponent in an ocean ensemble prediction model

Mateusz Matuszak, Johannes Röhrs, Pål Erik Isachsen, and Martina Idžanović

Data sets

Barents-2.5 ocean and ice forecast model archive Norwegian Meteorological Institute https://thredds.met.no/thredds/fou-hi/barents_eps.html

Model code and software

mateuszmatu/LCS: FTLE computation software release for article M. Matuszak https://doi.org/10.5281/zenodo.10797134

OpenDrift/opendrift: OpenDrift compliant with both Python2 and Python3 K.-F. Dagestad et al. https://doi.org/10.5281/zenodo.1300358

Short summary

Lagrangian coherent structures (LCSs) describe material transport in ocean flow by describing transport and accumulation regions. We discuss the implications of model flow field uncertainty for finite-time Lyapunov exponents (FTLEs), which under certain conditions approximate LCSs. FTLEs add value to forecasting when they are certain and long-lived. Averaging FTLEs reveals where they are more certain and long-lived, often influenced by bottom topography.