An ash plume modeling and prediction system has been developed using AVS for visualization and a Cray supercomputer for model computations. A simulation of the December 15 encounter with ash clouds from Mount Redoubt by a jetliner provides strong support for the accuracy of the model. Although the satellite data for this event are relatively limited, agreement of the model with satellite data for other events is very good. The animated visualization of the eruption which was produced using AVS demonstrates that AVS is an extremely effective tool for developing visualizations and animations. The Spline Animator module was developed to perform flybys and may be used to construct animated curves or flight paths in 3D.
Future work on the volcanic ash cloud visualization system will focus on improving the accuracy of the ash plume model by incorporating more realistic physical relationships in order to obtain more complete results from the model, such as ashfall on the ground. While the isosurface technique provides an effective visualization of the boundaries of the ash cloud, it is not at all visually realistic. Future work will examine other visualization techniques, such as volume rendering, in order to produce more realistic representations of the ash cloud.
The application of visualization techniques to examine computational models which are integrated wth satellite imagery or geophysical data is becoming an increasingly important topic in the field of environmental sciences. Work which applies similar techniques to meteorological data is underway in the Research Applications Program (RAP) at the National Center for Atmospheric Research (NCAR). Data from current and planned atmospheric observing platforms will be processed by the National Oceanic and Atmospheric Administration into a high-resolution, four-dimensional grid of aviation-impact variables (icing, turbulence, ceiling, etc.) and state-of-the-atmosphere variables (wind, humidity, temperature, pressure).
The Aviation Weather Products Generator will ingest this database and create aviation weather products tailored for aviation system users (typically non-meteorologists). Users will graphically view weather at specific altitudes and along selected routes of flight. Products currently under development include Icing Severity Index, Turbulence Index, Ceiling and Visibility, Jet Stream, Storm Cell Location, Wind Shear, Terminal Weather Depiction, and Weather Impacted Airspace.
NCAR/RAP has developed a prototype advanced weather display system for Flight Service Specialists and Traffic Managers. This regional display enables users to look at weather in plan view at selected flight levels and along flight paths in vertical cross sections. Using simple "mouse" input, users can easily zoom and pan and select flight routes, flight altitudes, and products.
Many applications of such integrated modeling and visualization exist in the area of pollutant transport modeling and remediation. Typically, a time-dependent dispersion model is combined with known underground structures or hydrography to assess the effects of a chemical spill and the remediation efforts that are applied to it. As an example, oil spilled from the Exxon Valdez in Alaska's Prince William Sound was detected using infrared satellite imagery. By combining satellite images with models of ocean circulation, it was possible to predict the movement of the oil and erect barriers to protect critical shoreline areas.