TY - JOUR
T1 - The Lagrangian nature of fingering convection
AU - Lee, Harry
AU - Paparella, Francesco
N1 - Funding Information:
F.P. was supported by the New York University Abu Dhabi Research Institute grants CG002 (Center on Stability, Instability and Turbulence) and CG009 (Arabian Center for Climate and Environmental ScienceS). This work was supported in part through the NYUAD's Center for Research Computing resources, services and staff expertise.
Publisher Copyright:
© The Author(s), 2023. Published by Cambridge University Press.
PY - 2023/5/1
Y1 - 2023/5/1
N2 - We investigate the Lagrangian properties of fingering convection in a parameter regime that is far beyond marginality, but that does not lead to staircase formation. We find that most fluid particles perform very short vertical excursions before switching direction. Only a small fraction of them travels vertically in the same direction for lengths substantially larger than the typical spatial scales associated with fingering instabilities. These long travels are associated with vertical velocities, buoyancy anomalies and advective fluxes constrained within a relatively narrow range of values. Despite their limited occurrence, they contribute the overwhelming majority of the up-gradient buoyancy flux. A description of fingering convection emerges that partitions the fluid into an incoherent background, where fluxes may be down-gradient, and a set of relatively long-lived, coherent, buoyancy-carrying structures that travel vertically, interacting with each other.
AB - We investigate the Lagrangian properties of fingering convection in a parameter regime that is far beyond marginality, but that does not lead to staircase formation. We find that most fluid particles perform very short vertical excursions before switching direction. Only a small fraction of them travels vertically in the same direction for lengths substantially larger than the typical spatial scales associated with fingering instabilities. These long travels are associated with vertical velocities, buoyancy anomalies and advective fluxes constrained within a relatively narrow range of values. Despite their limited occurrence, they contribute the overwhelming majority of the up-gradient buoyancy flux. A description of fingering convection emerges that partitions the fluid into an incoherent background, where fluxes may be down-gradient, and a set of relatively long-lived, coherent, buoyancy-carrying structures that travel vertically, interacting with each other.
KW - coupled diffusion and flow
KW - double diffusive convection
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U2 - 10.1017/jfm.2023.311
DO - 10.1017/jfm.2023.311
M3 - Article
AN - SCOPUS:85159324540
SN - 0022-1120
VL - 962
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
M1 - A34
ER -