Advection mesoscale

Hauchecorne,A,Marchand,M.,Godin,S.and Souprayen,C. (1998) A High resolution advection model for the interpretation of ozone filaments observed in lower stratospheric ozone lidar profiles at mid-latitudes,Proceeding of the Europe Workshop on Mesoscale Processes in the stratosphere,Bad Tolz,Germany,in Press... 

Equation (12), when used in large-scale coarse resolution (non-eddy resolving) models, is incomplete in one other respect. The effect of mesoscale eddies on tracer transport includes an additional, advective-like mechanism sometimes referred to as bolus transport (see Gent and McWilliams, 1990 Gent et al., 1995). This can be included in Equation (12) as... 

In Section 4.3, example macroscale transport equations are derived for selected moments of the NDF. Having introduced the precise forms of the mesoscale advection models in Eq. (5.2), it is of interest to derive explicitly some example moment source terms resulting from these models. In order to do so, we will use the rules presented in Section 4.3.1 for phase-space integration. For simplicity, we consider only the advection term involving (Afp)i and assume that the only phase-space variables of interest are v and Vf, and that the model in Eq. (5.2) reduces to... 

Chapter 5 focuses on selected mesoscale models from the literature for key physical and chemical processes. The chapter begins with a general discussion of the mesoscale modeling philosophy and its mathematical framework. Since the number of mesoscale models proposed in the literature is enormous, the goal of the chapter is to introduce examples of models for advection and diffusion in real and phase space... 

Contrary to the convective internal boundary layer, a stable IBL develops when warmer air is advected from an upstream warmer land (or sea) sttrface to a cooler sea downstream. This situation is shown in Fig. lOc. The main difference between convective and stable IBLs is that the heat flux is directed upward (from a warm sea to cooler air) for a convective IBL and downward (from warm air to a cooler sea) for a stable IBL. A two-dimensional nirmerical mesoscale model was used by J. R. Garratt to investigate the internal structure and growth of a stably stratified IBL beneath warm continental air flowing over a cooler sea. An analytical model was also used by Garratt to study a stable IBL, and excellent agreement with the numerical results was found. This analytical model states that... 

Assumptions 1 and 2 have not been made in recent years in the models, however, since the numerical equations are actually easier to solve without these assumptions. Nonetheless, the spatial and temporal scales of mesoscale systems result in the two assuniptions being excellent approximations with respect to mesoscale-size systems. Assumption 3 is justified since the advection of (f) is much more significant in transferring

molecular motion on the mesoscale. 

Mesoscale models have predominately utilized the finite-difference and (for advection), the semi-Lagrangian approaches. A few groups have applied the finite-element method, but its additional computational cost has limited its use. The spectral method, which is most valuable for models without boundaries and for simulation without sharp spatial gradients, has not generally been used since mesoscale models have lateral boundaries. 

Substantial emissions of ecotoxic metals into the atmosphere occur in the heavily industrialized and highly populated regions of the world. To a large extent the ecotoxic metals are bound to fine aerosol particles and therefore, undergo mesoscalic transport and distribution with the wind or, after advection to the upper troposphere, even hemispherical transfer. 

---