ARAC and its Modernisation

The Atmospheric Release Advisory Capability (ARAC), located at Lawrence Livermore National Laboratory, has embarked on a multi-year modernisation effort that began over two years ago and is now well under way with full completion expected by the year 2000. The modemisation involves a new computer system, improved three-dimensional diagnostic flow and atmospheric dispersion models, and a completely new mesoscale prognostic atmospheric modelling capability. Terrain representation in the atmospheric transport flow and dispersion models will be continuous rather than the block-terrain representation in the earlier models. A UNIX-based distributed computing architecture will be the underlying framework for the 3-D visualisation tools, interactive graphical user interface applications, communications software, file management, database management, and modelling environment.