We present the results of a very large aspect ratio (A = 42.6) numerical simulation of fully compressible turbulent convection in a polytropic atmosphere, and focus on the properties of large-scale flows. Mesoscale patterns dominate the turbulent energy spectrum. We show that these structures, which had already been observed in Boussinesq simulations by Cattaneo et al. (2001), have a genuine co...

The evolution of the mesoscale flow and precipitation distribution are investigated for a small mesoscale convective system (MCS) that evolved in a nearly barotropic environment exhibiting moderate instability and weak wind shear. Observations primarily from a single Doppler radar detail the growth of the MCS from the merger of several clusters and lines of vigorous convective cells into a matu...

By using a magnetosphere-ionosphere (M-I) coupling model of polar cap arcs [Zhu et al., 1993], a systematic model study of the effects of ionospheric background conductivity on the formation of polar cap arcs has been conducted. The variations of the ionospheric background conductivity in the model study cover typical ionospheric onditions, including solar minimum, solar maximum, winter, and su...

[1] Mesoscale variability where the East Australian Current (EAC) separates from the coast is studied using sea surface temperature and surface velocity streamfunction observed by satellite and a regional numerical model. The mean circulation simulated by the model (the Regional Ocean Modeling System (ROMS)) is compared to a high-resolution regional climatology, and the realism of the simulated...

This essay concerns precipitating convective cloud systems and convectively-driven mesoscale circulations (“mesoscale convection”) and their role in the large-scale structure of the atmosphere. Mesoscale convection is an important and ubiquitous process on scales of motion spanning a few kilometers to many hundreds of kilometers. It plays a role in the input of energy to the climate system thro...

A three-dimensional semi-implicit edge-based unstructured-mesh model is developed that integrates nonhydrostatic anelastic equations, suitable for simulation of small-to-mesoscale atmospheric flows. The model builds on nonoscillatory forwardin-time MPDATA approach using finite-volume discretization and admitting unstructured meshes with arbitrarily shaped cells. The numerical advancements are e...

Atomistic lattice-gas models for surface reactions can accurately describe spatial correlations and ordering in chemisorbed layers due to adspecies interactions or due to limited mobility of some adspecies. The primary challenge in such modeling is to describe spatiotemporal behavior in the physically relevant "hydrodynamic" regime of rapid diffusion of (at least some) reactant adspecies. For s...

A nonreactive Lagrangian atmospheric diffusion model is used for the simulation of SO2 concentration around the As Pontes 1400-MW power plant located in northwestern Spain. This diffusion model has two kinds of input: 1) diagnostic wind fields from real measurements and 2) forecast wind fields from a 24-h mesoscale prediction. This model-based system is applied for a particular day around the A...

Stream mesoscale habitats have systematic topographic relationships to hyporheic flow patterns, which may create predictable temperature variation between mesoscale habitat types. We investigated whether systematic differences in temperature metrics occurred between mesoscale habitats within reaches of small streams tributary to the upper Little Tennessee River, southern Appalachians. Surface w...

ACS Symposium Series Book: Interfacial Properties on the Submicron Scale; eds.: J. Frommer, R. Overney; Series 781 (in press 2000) 1 This chapter discusses the problematic nature of interfacial sciences when constrained to the mesoscale. Interfacial sciences are trapped between the atomistic and the threedimensional bulk regimes – the mesoscale. We experience a breakdown of phenomenological des...