The Dust REgional Atmospheric Model (DREAM) is an integrated modeling system designed to accurately describe the dust cycle in the atmosphere.  It is based on the SKIRON/Eta modeling system and the Eta/NCEP regional atmospheric model.  The dust modules of the entire system incorporate the state of the art parameterizations of all the major phases of the atmospheric dust life such as production, diffusion, advection, and removal.  These modules also include effects of the particle size distribution on aerosol dispersion.  The dust production mechanism is based on the viscous/turbulent mixing, shear-free convection diffusion, and soil moisture.  In addition to these sophisticated mechanisms, very high resolution databases, including elevation, soil properties, and vegetation cover are utilized.  The entire system is easily configurable and transferable to any place on the Earth, it can cover domains on almost any size, and its horizontal resolution can vary from about 100 km up to approximately 4 km.  It can run on one-way-nested form if necessary.  The performance of the system has been tested for various dust storm episodes, in various places and resolution using gridded analysis or forecasting fields from various sources (ECMWF and NCEP) for initial and boundary conditions.  The system is in operational use during the last two years, providing 72 hour forecasts for the Mediterranean region.

The model has two parts: 1) the atmospheric modeling system and 2) the dust concentration module.  The atmospheric modeling system is the SKIRON forecasting system, which is based on the 1997 version of the Eta/NCEP model.  Several new improvements are contained in the actual model version: a new positive-definite shape-preserving advection scheme, the turbulent mixing scheme, and new schemes for the atmospheric radiation and surface land processes.  The second module introduces a number of new improvements: first, a new scheme for dust production is applied on the basis of a more sophisticated parameterization of dust mobilization process; second, a four-particle instead of one-particle size scheme is implemented to simulate more accurately the size-dependent processes; third, topography, soil, and vegetation-type data used are of higher resolution than the original Eta/NCEP model; and fourth, new parameterization scheme for dry deposition is applied.