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Updated: May 24, 2026
08:01
The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Asymptotic diffusion coefficients and anomalous diffusion in a meandering jet flow under environmental fluctuations
A von Kameke1, F Huhn, V Pérez-Muñuzuri
1Group of Nonlinear Physics, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
Summary
This study reveals how noise intensity affects diffusion in a Gulf Stream-like flow. Different diffusion regimes were found, influenced by flow dynamics and internal circulations.
Area of Science:
- Fluid dynamics
- Atmospheric science
- Nonlinear dynamics
Background:
- The Gulf Stream's complex dynamics influence global weather patterns.
- Understanding diffusion is crucial for modeling oceanic and atmospheric transport.
- Previous studies have not fully explored noise intensity's role in jet stream-like flows.
Purpose of the Study:
- To investigate the dependence of asymptotic diffusion on noise intensity in a Hamiltonian flow.
- To identify and characterize different diffusion regimes within the flow.
- To elucidate the role of inner circulation regimes in observed diffusion behaviors.
Main Methods:
- Simulated a Hamiltonian flow mimicking the Gulf Jet Stream.
- Analyzed asymptotic diffusion across a range of noise intensities.
- Investigated the relationship between diffusion, noise intensity, and flow meander amplitude.
Main Results:
- Observed three distinct diffusion regimes based on noise intensity.
- Found that for intermediate noise, diffusion decreases linearly with meander amplitude.
- Identified superdiffusion and a return to diffusion at higher noise intensities.
Conclusions:
- Asymptotic diffusion in this system is non-trivially dependent on noise intensity.
- Inner circulation regimes are key to understanding the observed diffusion patterns.
- The study provides insights into transport mechanisms in complex fluid flows.
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