Lagrangian Dispersion in Experimental Stratified Turbulence
Abstract
Lagrangian measurements of tracer particle dispersion in stratified turbulence are presented from a large-scale experiment achieving both high buoyancy Reynolds numbers and low Froude numbers-a regime characteristic of oceanic conditions. Stratification has a pronounced effect on the vertical particle dispersion, which is observed to be constrained to distances on the order of the buoyancy scale wstd/N, where wstd is the standard deviation of the vertical velocity and N is the Brunt-Väisälä frequency. As expected in strongly nonlinear, stratified turbulence, the frequency spectrum of the Lagrangian velocity becomes isotropic at frequencies higher than N. The spectral decay follows a 1/f3 scaling, which contrasts with the 1/f2 behavior typical of homogeneous isotropic turbulence. At time scales corresponding to internal waves, the statistics of velocity increments remain Gaussian, consistent with the weakly nonlinear regime of wave turbulence. At smaller scales, however, the flow exhibits strongly non-Gaussian statistics, indicative of fully nonlinear turbulent dynamics driven by wave breaking.
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BibTeX
@article{magnier2026lagrangian,
title = {{Lagrangian Dispersion in Experimental Stratified Turbulence}},
author = {Maëlys Magnier and Costanza Rodda and Clément Savaro and Pierre Augier and Nathanaël Machicoane and Thomas Valran and Samuel Viboud and Nicolas Mordant},
journal = {Physical Review Letters},
year = {2026},
month = oct,
doi = {10.1103/8nm7-pm39},
url = {https://hal.science/hal-05793563v1},
note = {CC BY-NC 4.0},
}
RIS
TY - JOUR
TI - Lagrangian Dispersion in Experimental Stratified Turbulence
AU - Maëlys Magnier
AU - Costanza Rodda
AU - Clément Savaro
AU - Pierre Augier
AU - Nathanaël Machicoane
AU - Thomas Valran
AU - Samuel Viboud
AU - Nicolas Mordant
PY - 2026
DA - 2026/10/16
JO - Physical Review Letters
DO - 10.1103/8nm7-pm39
UR - https://hal.science/hal-05793563v1
AB - Lagrangian measurements of tracer particle dispersion in stratified turbulence are presented from a large-scale experiment achieving both high buoyancy Reynolds numbers and low Froude numbers-a regime characteristic of oceanic conditions. Stratification has a pronounced effect on the vertical particle dispersion, which is observed to be constrained to distances on the order of the buoyancy scale w_std/N, where w_std is the standard deviation of the vertical velocity and N is the Brunt-Väisälä frequency. As expected in strongly nonlinear, stratified turbulence, the frequency spectrum of the Lagrangian velocity becomes isotropic at frequencies higher than N. The spectral decay follows a 1/f^3 scaling, which contrasts with the 1/f^2 behavior typical of homogeneous isotropic turbulence. At time scales corresponding to internal waves, the statistics of velocity increments remain Gaussian, consistent with the weakly nonlinear regime of wave turbulence. At smaller scales, however, the flow exhibits strongly non-Gaussian statistics, indicative of fully nonlinear turbulent dynamics driven by wave breaking.
SN - 0031-9007
SN - 1079-7114
ER -