Optimal perturbation for two-dimensional vortex systems: route to non-axisymmetric state
Sign Up to like & getrecommendations! Published in 2018 at "Journal of Fluid Mechanics"
DOI: 10.1017/jfm.2018.689
Abstract: We investigate perturbations that maximize the gain of disturbance energy in a two-dimensional isolated vortex and a counter-rotating vortex pair. The optimization is carried out using the method of Lagrange multipliers. For low initial energy… read more here.
Keywords: state; vortex; optimal perturbation; gain ... See more keywords
Early evolution of optimal perturbations in a viscosity-stratified channel
Sign Up to like & getrecommendations! Published in 2021 at "Journal of Fluid Mechanics"
DOI: 10.1017/jfm.2020.1160
Abstract: Abstract This work shows how the early stages of perturbation growth in a viscosity-stratified flow are different from those in a constant-viscosity flow, and how nonlinearity is a crucial ingredient. We derive the viscosity-varying adjoint… read more here.
Keywords: viscosity stratified; viscosity; nonlinear optimal; optimal perturbations ... See more keywords
A useful approach to sensitivity and predictability studies in geophysical fluid dynamics: conditional non-linear optimal perturbation
Sign Up to like & getrecommendations! Published in 2020 at "National Science Review"
DOI: 10.1093/nsr/nwz039
Abstract: Abstract In atmospheric and oceanic studies, it is important to investigate the uncertainty of model solutions. The conditional non-linear optimal perturbation (CNOP) method is useful for addressing the uncertainty. This paper reviews the development of… read more here.
Keywords: conditional non; linear optimal; non linear; method ... See more keywords
Non-Modal Three-Dimensional Optimal Perturbation Growth in Thermally Stratified Mixing Layers
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DOI: 10.3390/fluids6010037
Abstract: A non-modal transient disturbances growth in a stably stratified mixing layer flow is studied numerically. The model accounts for a density gradient within a shear region, implying a heavier layer at the bottom. Numerical analysis… read more here.
Keywords: growth; three dimensional; non modal; optimal perturbation ... See more keywords
Error Evolutions and Analyses on Joint Effects of SST and SL via Intermediate Coupled Models and Conditional Nonlinear Optimal Perturbation Method
Sign Up to like & getrecommendations! Published in 2023 at "Journal of Marine Science and Engineering"
DOI: 10.3390/jmse11050910
Abstract: A seasonal predictability barrier has long been noticed in ENSO forecasting with numerical models. Previous studies explored the impact of seasonal optimal initial perturbation evolutions in sea surface temperature anomalies (SSTA) on ENSO forecasting using… read more here.
Keywords: optimal perturbation; error; intermediate coupled; conditional nonlinear ... See more keywords