Probing the complexities of climate and other chaotic systems is the goal of CAREER project

Mark Paul

Mark Paul

BLACKSBURG, Va., April 23, 2008 – Understanding the dynamics of large, chaotic systems, such as weather and climate, is the goal of Virginia Tech College of Engineering researcher Mark Paul, who has received a $400,000 National Science Foundation Faculty Early Career Development Program (CAREER) Award to support his research.

The five-year CAREER grant awarded to Paul, an assistant professor in the Department of Mechanical Engineering, is the National Science Foundation’s most prestigious award for creative junior faculty considered to be future leaders in their academic fields.

“Despite their importance in many areas of engineering and science, nonequilibrium systems — systems driven out of equilibrium — remain difficult to analyze, control, design, and predict,” Paul said.

Examples of nonequilibrium systems include weather and climate, the efficiency of combustion and chemical reactions, the convection of biological organisms in the oceans, heart dynamics, crystal growth from a melt, and fluid turbulence.

The difficulty in understanding these systems arises because of the complex way that their spatiotemporal patterns (variations in both space and time) affect the transport of energy and matter, Paul said. A particular challenge is to understand spatiotemporal chaos, a commonly observed behavior of nonequilibrium systems in which properties of the systems evolve chaotically in space and time.

To build a better understanding of such complex systems, Paul will use Virginia Tech’s System X supercomputer to conduct large-scale numerical simulations of the chaotic fluid motion that occurs when a shallow fluid layer is heated uniformly from below. The results will be used to probe the origins and basic building blocks of spatiotemporal chaos.

Paul also will explore two transport problems through these simulations. One is the enhancement of combustion efficiency in the presence of fluid velocity fields. An understanding of these dynamics is of direct relevance to important questions regarding energy production and consumption. The second problem is fluid transport driven by the activity of biological organisms suspended in fluid.

“The dynamics of biomass — composed of vast numbers of microorganisms — in oceans and rivers, for example, is an important component of climatology,” Paul said. “In this case, the complex fluid motion is driven by the activity of suspended biological organisms, rather than by thermal fluctuations. The fundamental insights gained through this research could lead to improvements in developing climate models.”

Each CAREER project has an educational component. Paul will work with the Virginia Tech Center for the Enhancement of Engineering Diversity to develop hands-on numerical experiments that will enable pre-college students to explore chaotic dynamics for themselves. The numerical experiments, to be made available on a website, will demonstrate the difficulty of weather prediction, for example, and the scientific meaning of the popular phrase, “the butterfly effect.” Paul also is developing a new graduate course on spatiotemporal chaos.

Paul joined the Virginia Tech faculty in 2004 after holding post-doctoral positions at the California Institute of Technology and Duke University. He has served visiting appointments at the Isaac Newton Institute for Mathematical Sciences in Cambridge, England, and at the Kavli Institute of Theoretical Physics at the University of California at Santa Barbara.

He completed his Ph.D. and master’s degree in mechanical engineering and his bachelor’s degree in aerospace engineering, all at the University of California at Los Angeles.