Model Development

Simulations will be performed with both the COMMAS and MM5 models. COMMAS (COllaborative Model for Multiscale Atmospheric Simulation) is an evolving three-dimensional non-hydrostatic mesoscale model developed by Wicker and Wilhelmson (1995). The model is based upon the compressible, Reynolds-averaged Navier-Stokes equations and can be used for nested-grid simulations. Peckham (1999) has extensively modified the model to include a generalized terrain-following coordinate transformation (Gal-Chen and Sommerville, 1975), parameterizations for surface radiation for a cloudy atmosphere (Benjamin, 1986) and land surface processes (Deardorff 1972, 1978). The model has been parallelized for current computer architectures like the SGI Origin 2000 at NCSA. Analysis of COMMAS data is handled through a variety of software developed for the model. This includes software developed in the group (Wilhelmson et al., 1993), Vis5D, software developed for immersive virtual reality using the CAVE or Immersedesk ( Wilhelmson et al., 1996), and soon new analysis software developed by Wicker based on IDL.

A parallel version of MM5 developed by J. Michalakes is being used for several case studies. This parallel version is one component in the new infrastructure computing environment being developed in the Environmental Hydrology Group at NCSA (Wilhelmson is a co-lead). This effort is aimed at coupling a variety of models (e.g. atmospheric models such as MM5 and ARPS, surface run-off models, river models) in a distributed computing environment using Globus. VisAD (VisAD overview) provides the visualization and collaborative environment and is being coupled with immersive virtual reality capabilities. One test environment for this infrastructure will be flash flood forecasting and analysis. In addition, Dr. Wilhelmson is working with the developers at NCAR (including Drs. Klemp, Skamarock, and Michalakes) on the development of a high performance version of the new WRF model (model url, paper).