Semi-analytical eddy-viscosity and backscattering closures for 2D geophysical turbulence

Fuente: arXiv
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Autori principali: Guan, Yifei, Hassanzadeh, Pedram
Natura: Preprint
Pubblicazione: 2025
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author Guan, Yifei
Hassanzadeh, Pedram
author_facet Guan, Yifei
Hassanzadeh, Pedram
contents Physics-based closures such as eddy-viscosity and backscattering models are widely used for large-eddy simulation (LES) of geophysical turbulence for applications including weather and climate prediction. However, these closures have parameters that are often chosen empirically. Here, for the first time, we semi-analytically derive the parameters of the Leith and Smagorinsky eddy-viscosity closures and the Jansen-Held backscattering closure for 2D geophysical turbulence. The semi-analytical derivation provides these parameters up to a constant that can be estimated from the turbulent kinetic energy spectrum of a few snapshots of direct numerical simulation (DNS) or other high-fidelity (eddy resolving) simulations, or even obtained from earlier analytical work based on renormalization group. The semi-analytically estimated closure parameters agree with those obtained from online (a-posteriori) learning in several setups of 2D geophysical turbulence in our earlier work. LES with closures that use these parameters can correctly reproduce the key statistics of DNS, including those of the extreme events and interscale energy and enstrophy transfers, and outperform the baselines (dynamic Leith and Smagorinsky and the latter with standard parameter).
format Preprint
id arxiv_https___arxiv_org_abs_2504_09670
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Semi-analytical eddy-viscosity and backscattering closures for 2D geophysical turbulence
Guan, Yifei
Hassanzadeh, Pedram
Fluid Dynamics
Geophysics
Physics-based closures such as eddy-viscosity and backscattering models are widely used for large-eddy simulation (LES) of geophysical turbulence for applications including weather and climate prediction. However, these closures have parameters that are often chosen empirically. Here, for the first time, we semi-analytically derive the parameters of the Leith and Smagorinsky eddy-viscosity closures and the Jansen-Held backscattering closure for 2D geophysical turbulence. The semi-analytical derivation provides these parameters up to a constant that can be estimated from the turbulent kinetic energy spectrum of a few snapshots of direct numerical simulation (DNS) or other high-fidelity (eddy resolving) simulations, or even obtained from earlier analytical work based on renormalization group. The semi-analytically estimated closure parameters agree with those obtained from online (a-posteriori) learning in several setups of 2D geophysical turbulence in our earlier work. LES with closures that use these parameters can correctly reproduce the key statistics of DNS, including those of the extreme events and interscale energy and enstrophy transfers, and outperform the baselines (dynamic Leith and Smagorinsky and the latter with standard parameter).
title Semi-analytical eddy-viscosity and backscattering closures for 2D geophysical turbulence
topic Fluid Dynamics
Geophysics
url https://arxiv.org/abs/2504.09670