Deciphering the role of small-scale inhomogeneity on geophysical flow structuration: a stochastic approach

Werner Bauer (1) , Pranav Chandramouli (1, 2) , Bertrand Chapron (3) , Long Li (2, 4) , Etienne Mémin (1, 2)

1 FLUMINANCE - Fluid Flow Analysis, Description and Control from Image Sequences
2 IRMAR - Institut de Recherche Mathématique de Rennes
3 IFREMER - Institut Français de Recherche pour l'Exploitation de la Mer
4 Inria Rennes – Bretagne Atlantique

An important open question in fluid dynamics concerns the effect of small-scales in structuring a fluid flow. In oceanic or atmospheric flows, this is aptly captured in wave-current interactions through the study of the well-known Langmuir secondary circulation. Such wave-current interactions are described by the Craik-Leibovich system, in which the action of a wave induced velocity, the Stokes drift, produces a so called "vortex force" that causes streaking in the flow. In this work, we show that these results can be generalized as a generic effect of the spatial inhomogeneity of the statistical properties of the small-scale flow components. As demonstrated, this is well captured through a stochastic representation of the flow.

Domaines: Océan, Atmosphère; Dynamique des Fluides [physics.flu-dyn]; Systèmes dynamiques [math.DS]

Werner Bauer, Pranav Chandramouli, Bertrand Chapron, Long Li, Etienne Mémin. Deciphering the role of small-scale inhomogeneity on geophysical flow structuration: a stochastic approach. Journal of Physical Oceanography, 2020, 50 (4), pp.983-1003. ⟨10.1175/JPO-D-19-0164.1⟩. ⟨hal-02398521⟩