[1] Using the ERA-40 reanalysis data, we study the different roles of synoptic and low-frequency eddies in sustaining the latitudinal shift of the low-level baroclinicity associated with the Southern Hemisphere Annular Mode. The eddy effect is assessed through the direct eddy thermal forcing via eddy heat flux and the indirect forcing via eddy-driven mean meridional circulation (MMC). We find t...

Please cite this article in press as: Oldroyd HJ et http://dx.doi.org/10.1016/j.advwatres.2012.06.0 Thermal diffusivity of snow is an important thermodynamic property associated with key hydrological phenomena such as snow melt and heat and water vapor exchange with the atmosphere. Direct determination of snow thermal diffusivity requires coupled point measurements of thermal conductivity and d...

A new formulation for eddy diffusivity is derived from Taylor’s statistical theory on turbulence and from a generalized turbulent spectral equation for energy in the inertial subrange. The latter aspect is taken into account for considering the intermittency phenomenon within turbulence model. The approach is used for a stable atmospheric boundary layer parameterization. r 2005 Elsevier B.V. Al...

The objective is estimated the concentration of air pollution, by solving the atmospheric diffusion equation (ADE) using Adomain decomposition method. The solution depends on eddy diffusivity profile (K) and wind speed at the released point (u). We solve the ADE numerically in two dimensions using Adomain decomposition method, then, compared our results with observed data.

We consider stability of regimes of hydromagnetic thermal convection in a rotating horizontal layer with free electrically conducting boundaries, to perturbations involving large spatial and temporal scales. Equations governing the evolution of weakly nonlinear mean perturbations are derived under the assumption that the α−effect is insignificant in the leading order (e.g., due to a symmetry of...

The residual-based variational multiscale formulation is applied to develop a large eddy simulation (LES) model for compressible flows. In addition, a mixed model, in which a deviatoric Smagorinsky subgrid stress term is added to the RBVM terms to better model the Reynolds stresses is proposed. These models, along with the dynamic Smagorinsky-Yoshizawa-eddy diffusivity model are tested in predi...

Aqueous phase reactions are important, sometimes dominant (e.g., for SO2), pathways for the oxidation of air pollutants at the local and/or global scale. In many current chemical transport models (CTMs), the transport and aqueous reactions of chemical species are treated as split processes, and the subgrid-scale heterogeneity between cloudy and environmental air is not considered. Here using la...

Recent observations suggest that the export of Antarctic Bottom Water (AABW) from the Weddell Sea has a seasonal cycle in its temperature and salinity that is correlated with annual wind stress variations. This variability has been attributed to annual vertical excursions of the isopycnals in theWeddell Gyre, modifying the water properties at the depth of the Orkney Passage. Recent studies attr...

Integral methods are used to derive similarity solutions for several quantities of interest including the cross-stream velocity, Reynolds stress, the dominant turbulent kinetic energy production term, and eddy diffusivities of momentum and heat for axisymmetric and planar turbulent jets, plumes, and wakes. A universal constant is evaluated for axisymmetric and planar plumes. The cross-stream ve...

The geometric orientation of the subfilter-scale scalar-flux vector is examined in homogeneous isotropic turbulence. Vector orientation is determined using the eigenframe of the resolved strain-rate tensor. The Schmidt number is kept sufficiently large so as to leave the velocity field, and hence the strain-rate tensor, unaltered by filtering in the viscous-convective subrange. Strong preferent...