SCD FY97 Annual Scientific Report

Visualization Lab purpose and facilities

The Visualization Lab is a synthesis of people, advanced systems, tools, and techniques aimed at a simple goal: to advance atmospheric science by direct application of state-of-the-art visualization. The idea is to serve as a catalyst in the service of science, bringing useful new technologies to bear on valid problems, then developing that technology into user-friendly tools. Scientific relevance is a primary metric of success. Communication of end results to the scientific community and general public is a priority.

These goals are targeted with a variety of lab resources, each of which is presented in brief along with the year's accomplishments.

Mesa Visualization Lab

The Mesa Visualization Lab supports research, development, and production in all areas of atmospheric science visualization and consists of several components: a visual supercomputer (SGI Onyx), a digital animation system (SGI Indigo-2) , a visualization server (SGI Challenge), and office/user/visitor workstations. Focus areas for the lab include high-performance visualization of large complex simulation datasets, volume and flow visualization, distributed visualization, advanced web technologies including VRML, HDTV, and immersive environments.

During FY97, Mesa Visualization Lab systems were basically held in maintenance mode, with upgrades limited to storage capacity. At an age of 4+ years, both the flagship system, an SGI Onyx, and the digital animation system will be entering into an EOL (End Of Life) phase during FY98. During FY97 the focus was on advancing projects as well as possible while preparing plans for upgrading the facility in FY98.

Foothills Visualization Lab

The Foothills Visualization Lab provides a self-service animation production capability that includes support for MPEG movie creation and modest exploratory visualization. The FL lab was held in maintenance mode during the course of FY97 and efforts were made, unsuccessfully, to gain funding to enhance the lab and collocate it with HAO's Imaging Lab. Current plans call for the facility to enter into an EOL phase in FY98.

TAGS video

The Text and Graphics System (TAGS) included a batch video animation production facility that complemented the interactive services offered in the visualization labs. TAGS was successfully decommissioned at the end of FY97, and the video animation services and support were transitioned to the Foothills Visualization Lab.

Visualization Theater

The mobile arm of the lab, The Visualization Theater (VT), was deployed with great success at the SC96 in Pittsburgh and the AMS97 conference in Long Beach. Late in FY97 work began on engineering a next-generation VT which would be cost-effective, portable, visually excellent, and conducive to presenting stereo material to large audiences. Procurement for the new system is slated for early FY98.

Standard Operating Procedures for the lab

During FY97, a set of Standard Operating Procedures was instituted for the lab. These procedures basically addressed the creation of a specified set of visualization products. These include a website, video output, stereo animation, high-resolution imagery, and lay-accessible text. Our motivation is to provide a visible and persistent library of visualization work while at the same time streamlining a mechanism for communicating and sharing the information with others. This is important from a practical standpoint as requests for the lab's visual materials, from both internal and external sources, have grown rapidly.

Science

The first priority of the Visualization Lab is to provide the human and computational resources necessary for gaining new insight into scientific research. Over the course of the year, the lab was host to a number of research projects from across the spectrum of the NCAR programs.

The lab's first major foray into global chemistry centered on a CCM2 simulation of sulfate-aerosol evolution by Phil Rasch (CGD), Mary Barth (ACD), and Jeff Kiehl (CGD). Isosurface and volume-visualizations of sulfate-aerosol levels color-coded by country of origin were prepared for the year-long sequence. Results were encouraging, and tentative plans were made to begin work on a T170 simulation in FY98.

Solar Magnetic Flux Tubes (MFTs), also called "pores," are magnetic field concentrations near the surface of the sun caused by surrounding convective motion. The new volsh software was used to create stereo volume-visualizations depicting the formation and collapse of MFTs as prescribed by a simulation conducted by Peter Fox (HAO).

The lab was involved in quite a number of mesoscale simulations during the course of the year. A simulation of a squall line with a mesoscale convective vortex proved to be an excellent testing ground for new flow visualization techniques. Cloud water, the rain field, the cold pool, and particle trajectories were combined to generate an excellent and detailed visual treatment of the simulation. Investigators included Morris Weisman, Chris Davis, Bill Skamarock, and Joe Klemp, all of MMM.

Three incarnations of the Clark-Hall model were visualized over the course of the year. The first of these, an explosive forest fire, was a refinement of work begun in FY96 and focused on experiments with high-density particle trajectories in the fire's flow field.

Shortly after that, a simulation of Tropical Storm Russ over Lantau Island (site of the new Hong Kong Airport) was visualized with an emphasis on studying mechanical turbulence and the nature of vortex shedding relative to topography. Visualizations of the vorticity, enstrophy, and Bernoulli Energy fields were studied in juxtapostion to the island's topography.

Late in the year, a large-scale simulation of Clear Air Turbulence in a Colorado Windstorm was developed for a particular aircraft flight incident. At 20-meter resolution and with coverage of a substantial portion of the Boulder/Denver Front Range area, this model produced a stunning 60 gigabytes of data for the innermost domain. This represented the largest dataset encountered in the lab and required numerous adjustments to tools and systems to accomodate it. In addition, the complex turbulence patterns and intervariable relationships were difficult to understand even using the virtual 3D imaging approach and interactivity. The visual techniques we employed provided insights into new patterns of turbulence unattainable via traditional approaches.

On these projects, principal investigator Terry Clark worked with many collaborators; these included Bill Hall (MMM), Janice Coen (MMM), Robert Kerr (MMM), and Larry Radke (ATD).

Enabling technologies

Cutting-edge visualization hinges on a diverse and rapidly changing collection of enabling technologies. Visual computing, parallel systems, virtual environments, and high-performance networks and I/O are all important elements of the technology mix that allow us to forge ahead in exploring science in new and useful ways. Custom development is also a critical component, and of all of this year's accomplishments, the successful integration of virtual 3D imaging into all phases of lab work ranks at the top of our technology achievements.

VIS5D extensions

The VIS5D package has been a mainstay of the lab's tool set for the last year. During the course of FY97, three major enhancements of the package were developed locally: comprehensive support for stereo on the OpenGL platform, support for VRML 2.0 (Virtual Reality Modeling Language Version 2.0), and support for large-scale flow visualization. The stereo capability has proved to be invaluable, particularly for very-high-resolution simulations with intricate patterns and complex intervariable relationships. The flow visualization feature was used to excellent effect on a mesoscale vortex simulation, and the VRML capabilities will position us very well for FY98 efforts in the web-visualization realm.

volsh

Another major focus area was that of high-performance volume visualization. volsh is a locally developed volume visualization tool based on shear-warp optimization techniques. Version 1.0 was released to the general public this year and substantial enhancements to the code were made thereafter. In particular, support for HP and SGI multiprocessor systems was added, and we expect interactive rendering rates to be achievable for 128x128x128 volumes in FY98.

dmp

The lab's Digital Movie Player, dmp, provides workstation-based playback of digital movies, both stereo and mono varieties. Efficiency and user interface components were upgraded significantly over the year.

Collaboration

The Visualization Lab maintains collaborative relationships with a number of research entities, universities, and companies. This is a brief description of each relationship:

Lab presentations and events:

Presentations and outreach


| Next page | Top of this section | Table of contents |

| NCAR | UCAR | NSF | NCAR FY97 ASR |