A2C is a single model, which allows the information between the mesoscale and CFD models to interact in a two-way flow, realistically mimicking actual atmospheric conditions. A2C also considers the thermal (cooling/heating) effects of buildings, something that neither mesoscale models nor CFD models are able to accomplish. For example, during daylight hours, one side of a building is usually cooler than the other side; this affects the airflow around the building. A2C can simulate a forecast of air flows and the transport and dispersion of air pollutants—an important feature when accuracy counts.

A2C predicts and presents the physics of airflow and air-borne particle diffusion, including:
PHYSICS

• Airflow around buildings
• Single model seamlessly integrate from mesoscale to microscale
• Thermal effects on buildings on airflows
• Three-dimensional forecast
• Second-moment turbulence closure
• Complex terrain
• Tall tree canopy
• Land use (roughness, albedo, soil moisture, anthropogenic heat)
• Ensemble cloud model
• Shortwave and longwave radiation parameterization in fog and clouds
• Precipitation microphysics
• Non-hydrostatic pressure
• Non-neutrally buoyant plume
• Concentration fluctuation

NUMERICAL AND GRAPHICS

• 3D Animation
• Nested grid
• Four-dimensional data assimilation
• Interface with tower, rawinsonde, and large-scale weather data
• Vertical profile plots of wind, temperature, and turbulence
• Wind vector distribution plots in the vertical and horizontal cross section
• Surface concentration contour plots
• Vertical cross section plots of concentration contours

• Runs on UNIX, LINUX, and Windows environments
• Runs on desktop and laptop workstations and PCs
• User friendly menu system
• Terrain data extraction interface for a HOTMAC input file
• 3-d visualization interface for animation
• Restart capability