Visualization of volcanic ash clouds

Ash clouds resulting from volcanic eruptions are a serious hazard to aviation safety. In Alaska alone, there are over 40 active volcanoes whose eruptions may affect more than 40,000 flights using the great circle polar routes each year. The clouds are especially problematic because they are invisible to radar and nearly impossible to distinguish from weather clouds. The Arctic Region Supercomputing Center and the Alaska Volcano Observatory have collaborated to develop a system for predicting and visualizing the movement of volcanic ash clouds when an eruption occurs. The output from the model is combined with a digital elevation model to produce a realistic view of the ash cloud which may be examined interactively from any desired point of view at any time during the prediction period. This paper describes the visualization techniques employed in the system and includes a video animation of the 1989 Mount Redoubt eruption which caused complete engine failure on a 747 passenger jet