A lumped unconfined aquifer model has been developed and interactively coupled to a land surface scheme in a companion paper. Here, the issue of the representation of subgrid variability of water table depths (WTDs) is addressed. A statistical–dynamical (SD) approach is used to account for the effects of the unresolved subgrid variability of WTD in the grid-scale groundwater runoff. The dynamic...

Fine-resolution three-dimensional fields have been produced using the Community Gridpoint Statistical Interpolation (GSI) data assimilation system for the U.S. Department of Energy’s Atmospheric Radiation Measurement Program (ARM) Southern Great Plains region. The GSI system is implemented in a multiscale data assimilation framework using theWeather Research and Forecastingmodel at a cloud-reso...

The intentional enhancement of cloud albedo via controlled sea-spray injection from ships (marine cloud brightening) has been proposed as a possible method to control anthropogenic global warming; however, there remains significant uncertainty in the efficacy of this method due to, amongst other factors, uncertainties in aerosol and cloud microphysics. A major assumption used in recent cloudand...

Large eddy simulations (LES), where the large-scale motions are explicitly computed, is a promising tool for numerical simulations of reactive flows which generally exhibit large coherent structures. Nevertheless, subgrid-scale models have to be developed to describe the effects of the smaller flow motions not resolved in the simulation. An experimental method is presented for validation and de...

Field measurements of conductivity, porosity, etc. have shown their are high heterogeneity, the bounds of such heterogeneity increasing as the scale of observations changes. This has led to the development of fractal models, renormgroup methods, and methods of subgrid modeling. The subgrid modeling approach, associated with problems of the subsurface hydrodynamics, is presented. We consider a s...

Maximum entropy states or statistical mechanical equilibrium solutions have played an important role in the development of a fundamental understanding of turbulence and its role in geophysical flows. In modern general circulation models of the earth’s atmosphere and oceans most parameterizations of the subgrid-scale energy and enstrophy transfers are based on ad hoc methods or ideas developed f...

In this paper we present an analytical study of a subgrid scale turbulence model of the threedimensional magnetohydrodynamic (MHD) equations, inspired by the Navier-Stokes-α (also known as the viscous Camassa-Holm equations or the Lagrangian-averaged Navier-Stokes-α model. Specifically, we show the global well-posedness and regularity of solutions of a certain MHD-α model (which is a particular...