Data-based stochastic subgrid-scale parametrization: an approach using cluster-weighted modelling.

Cluster-weighted stochastic subgrid-scale modelling

This paper presents the main results of a recent publication (Kwasniok, 2011a). A new approach for data-based stochastic parametrisation of unresolved scales and processes in numerical weather and climate prediction models is introduced. The subgrid-scale model is conditional on the state of the resolved scales, consisting of a collection of local models. A clustering algorithm in the space of ...

Stochastic subgrid-scale modelling for non-equilibrium geophysical flows.

Methods motivated by non-equilibrium statistical mechanics of turbulence are applied to solve an important practical problem in geophysical fluid dynamics, namely the parametrization of subgrid-scale eddies needed in large-eddy simulations (LESs). A direct stochastic modelling scheme that is closely related to techniques based on statistical closure theories, but which is more generally applica...

Data-driven stochastic parametrization for subgrid-scale tropical convective area fraction

A-priori dynamic test for deterministic/stochastic modeling in large-eddy simulation of turbulent flow

The coherent/incoherent decomposition of the subgrid-scale stresses based on the wavelet de-noising procedure is exploited in the framework of large-eddy simulation of turbulence. Dynamic a-priori tests based on the perfect modeling approach are performed for decaying isotropic turbulence. The theoretical performances of deterministic/stochastic subgrid-scale models are evaluated during the sim...

Several Unresolved Issues in Numerical Modelling of Geophysical Flows

This paper discusses several issues in the numerical modelling of atmospheric flow which have been left unresolved. These include the influence of partial model resolution of features that are represented in a model by only a few grid points and the implication of this inadequacy in terms of the parametrization of subgrid-scale processes. As a result of nonlinear interactions, this lack of reso...