We develop a method for the modeling of flow discontinuities which can arise as weak solutions of inviscid conservation laws. Due to its similarity with recently proposed approximate deconvolution models for large-eddy simulation, the method potentially allows for a unified treatment of flow discontinuities and turbulent subgrid scales. A filtering approach is employed since for the filtered ev...

A new approach is proposed for stochastic parameterization of subgrid scale processes in models of atmospheric or oceanic circulation. The new approach relies on two key ingredients. First, the unresolved processes are represented by a Markov chain whose properties depend on the state of the resolved model variables. Second, the properties of this conditional Markov chain are inferred from data...

The Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) Goddard Profiling (GPROF) rainfall retrieval algorithm is an inversion type algorithm, which uses numerical cloud models and radiative transfer schemes to simulate the brightness temperatures that the TMI would see, thereby allowing one to relate hydrometeor profiles to brightness temperature. The variability in modeled hydro...

Four subgrid-scale models based on large eddy simulation (LES), such as Smagorinsky–Lilly (SL), dynamic (DSL), wall-adapting local eddy-viscosity (WALE), and kinetic-energy transport (KET) were used couple Ffowcs Williams–Hawkings equation to accurately analyze identify the characteristics position of sound sources rod–airfoil interaction. The results four compared with experimental data. It wa...

In this thesis, parameterizations of non-linear interactions in quasigeostrophic (QG) flows for severely truncated models (STM) and Large Eddy Simulations (LES) are studied. Firstly, using Direct Numerical Simulations (DNS), atmospheric barotropic flows over topography are examined, and it is established that such flows exhibit multiple equilibrium states for a wide range of parameters. A STM i...

The tools of optimal estimation are applied to the study of subgrid models for LargeEddy Simulation of turbulence. The concept of optimal estimator is introduced and its properties are analyzed in the context of applications to a priori tests of subgrid models. Attention is focused on the Cook and Riley model in the case of a scalar field in isotropic turbulence. Using DNS data, the relevance o...