For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Subgrid-scale variability is one of the main reasons why parameterizations are needed in large-scale models. Similarly, subpixel-scale cloud heterogeneity also plagues satellite retrievals of cloud and aerosol properties. Cloud heterogeneity, to some extent, can be represe...

Theories and numerical models of atmospheres and oceans are based on classical mechanics with added parameterizations to represent subgrid variability. Reformulated in terms of derivatives of information entropy with respect to large scale configurations, we find systematic forces very different from those usually assumed. Two examples are given. We see that entropic forcing by ocean eddies sys...

We are concerned with the chaotic flow fields of turbulent mixing. Chaotic flow is found in an extreme form in multiply shocked Richtmyer-Meshkov unstable flows. The goal of a converged simulation for this problem is to obtain converged solutions for such micro solution features as the joint probability distributions of the temperature and species concentration, as well as the macro features su...

A new subgrid eddy-viscosity model is proposed in this paper. Full details of the derivation of the model are given with the assumption of homogeneous turbulence. The formulation of the model is based on the dynamic equation of the structure function of resolved scale turbulence. By means of the local volume average, the effect of the anisotropy is taken into account in the generalized Kolmogor...

G lobal models are used in many applications, ranging from Numerical Weather Prediction (NWP) to seasonal prediction and climate simulation. Despite great computational advances, calculations using these models can still only afford grid spacing for which many of the important processes occurring in the atmosphere—most notably boundary layer processes as well as moist convection and cloud proce...

A subgrid turbulence model for the lattice Boltzmann method is proposed for high Reynolds number fluid flow applications. The method, based on the standard Smagorinsky subgrid model and a single-time relaxation lattice Boltzmann method, incorporates the advantages of the lattice Boltzmann method for handling arbitrary boundaries and is easily implemented on parallel machines. The method is appl...