Computational power continues to grow and subsequently modelers are carrying out simulations with increased temporal and spatial resolution. This, in turn, has resulted in increasingly larger volumes of data that need to be analyzed. Three dimensional visualization of this data is cumbersome because most software products were not designed to handle 10's of millions of grid zones per field. For example, Vis5D is a commonly used rendering tool in meteorology. While an excellent tool, the interactive surface rendering performance markedly degrades with larger data sets and thus the researcher often turns to two-dimensional visualization tools for interactive analysis. The Heirarchical Volume Renderer (HVR) is an alternative to surface rendering software and has been used to view three dimensional turbulence simulations with grids in excess of a billion zones. This interactive tool for creating single frames or animations has the potential to be valuable to geoscience researchers and operational forecasters.

Collaborating with the Laboratory of Computational Science and Engineering at the University of Minnesota, we are developing an interface to couple HVR to atmospheric data sets, such as those from the WRF model. HVR runs on ordinary Windows PCs using Open GL software rendering. The hierarchal nature of the software enables display of subjects closer to the viewer's location at high resolution, whereas subjects farther away are shown at lower resolution. This feature greatly reduces the computer resource requirements and permits truly interactive behavior for even billion zone volumes. HVR software provides a unique new tool for interactive investigation of model output and for developing animations of native and/or derived fields. Demonstrations of its capabilities will be shown at the conference.