The All Scale Atmsopheric Model (ASAM) is a numerical solver for atmospheric applications at all scales ranging from the globe up to building resolving simulations. The underlying compressible Euler equations in flux form are solved in an Eulerian framework. ASAM was initially designed for CFD (Computational Fluid Dynamics) simulations around buildings where the obstacles are included within a Cartesian grid by a cut cell approach. This approach is now extended to other orthogonal grids like the lat-lon grid. Due to the implicit time integration scheme there are no stability problems with small grid cells resulting from cut cells or cells near the poles. Physical processes can be prescribed as continuous-time processes with respect to the model variables without dependence on the time step.
ASAM is a developing research code and has a lot of different options to choose like numerical methods, number of variables and physical parameterizations (e.g. two-moment bulk microphysics scheme, precipitation, surface fluxes, radiation etc.). The code is used for testing new numerical approaches but also for process studies on different scales. Examples are LES (Large Eddy Simulations) of stratiform clouds, vortex generation in street canyons, orographic precipitation and so on. Current model applications are investigations on island effects in the trade wind regimes as well as on turbulent flow fields including microscale effects in an urban environment. ASAM is a fully parallelized code and is easily portable between different platforms (Linux, IBM, Mac).
ASAMgpu is a separately developed model with the focus on three-dimensional atmospheric simulations. It uses GPUs (Graphics Processing Units) to provide a maximum performance that enables 3D-LES on architectures ranging from a notebook, an ordinary gaming PC up to one or more high performance MultiGPU Nodes.