Over 50 people representing seven institutions exchanged ideas on multiscale computing of cloud physics at a workshop held Aug. 16-17 at Clayton Hall at the University of Deleware.

The workshop, hosted by the University of Delaware with support from the National Science Foundation (NSF), brought together experts in cloud physics, turbulent multiphase flows, applied mathematics, computer engineering and computer science to discuss interdisciplinary research issues related to the cloud physics.

This effort comes as a result of a collaborative project between the University and the National Center for Atmospheric Research (NCAR) in Boulder, Colo. Funded through NSF's Accelerating Discovery in Science and Engineering through Petascale Simulations and Analysis (PetaApps) program, the project is developing tools and simulation models to couple large-eddy simulation of cloud dynamics and direct numerical simulation of cloud microphysics on upcoming petascale computers. This information can then be used to develop cloud physics parameterization for the next-generation weather and climate models.

"Clouds play an essential role in the weather, the hydrological cycle, and the earth's climate system," says Lian-Ping Wang, a professor in the Department of Mechanical Engineering, with a joint appointment in the College of Earth, Ocean, and Environment, and principal investigator for the project. "We wanted to encourage dialogue among investigators within the project team and researchers from various disciplines to stimulate new ideas and approaches for multiscale problems."

Invited speakers Raymond Shaw and Jeffrey Marshall spoke at the event. Shaw, a cloud physicist from Michigan Technological University, explained the nature of multiscale interactions and turbulent fluctuations in clouds from observational perspectives. Marshall, a professor at University of Vermont, discussed complex physical issues and a wide range of applications of adhesive particles in electric fields.

"This type of research would not be possible without the interaction between experts from a broad range of disciplines," says Anette Karlsson, chair of the Department of Mechanical Engineering. "I am pleased we could host a workshop on such an innovative, multidisciplinary topic."

Scientific exchanges such as this are expected to continue as high-performance computing is now recognized as the third pillar, in addition to the traditional theoretical and experimental approaches, in supporting innovation and discovery in science and engineering.

"Since modeling the entire range of scales from sub-centimeter to global will never be possible, the development of novel theoretical and computational approaches is one way to move forward," explains Wojciech W. Grabowski, principal investigator and senior scientist in the Mesoscale and Microscale Meteorology Division at NCAR. "Beyond theoretical challenges, there is also a significant technical challenge related to efficient computation using contemporary and future computer architectures."

The workshop included oral and poster presentations by members of the project team, including three undergraduate Summer High-Performance Computing (HPC) Fellows supported by the project. In addition to Wang, University of Delaware speakers included Guang Gao, Distinguished Professor in the Department of Electrical and Computer Engineering; Xiaoming Li, assistant professor in the Department of Electrical and Computer Engineering; Louis Rossi, associate professor in the Department of Mathematical Sciences; and Chandra Kambhamettu, professor in the Department of Computer and Information Sciences. Workshop presentation files are available online.