Li-Wei Vivian Chao and Nancy Okeudo, both Ph.D. students in the Department of Atmospheric Sciences at Texas A&M University, have received funding from the Future Investigators in NASA Earth and Space Science and Technology (FINESST) program.

Chao’s research proposal aimed to leverage Clouds and the Earth’s Radiant Energy System (CERES) satellite measurements to develop an improved energy balance framework and constrain climate sensitivity by combining estimates of how the controlling factors for each component change as the climate warms.

“How much warming the world is going to experience in the future has always been an essential question,” Chao said. “The traditional way scientists have approached the problem has several known issues that result in the uncertainty of future temperature changes. The goal of my research is to revisit the concept of planetary energy balance by analyzing satellite measurements of the radiative flux from clouds and the non-cloud components of the atmosphere. The result of the research will hopefully improve the ability to predict future climate.”

The project is titled “Developing an Improved Energy Balance Framework Using CERES Planetary Energy Balance Observations,” and Dr. Andrew Dessler, professor of atmospheric sciences, is Chao’s advisor and will service as principal investigator of the project.

“Climate change is basically an energy balance problem,” Dessler said. “You have energy coming in from the sun balanced by heat radiated back to space. As we add carbon dioxide to the atmosphere, it throws these terms out of balance, leading to climate change. I think Vivian’s research will help us understand some of the fine points of this process and hopefully resolve some long-standing problems.”

Okeudo’s research centers on light scattering by dust aerosol particles and relevant downstream applications to satellite remote sensing.

“My research focus is on improving the physical geometric optics method (PGOM), an approximate method that calculates the single-scattering properties of moderate to large-sized particles,” Okeudo said. “The problem is that PGOM is inaccurate in calculating the single-scattering properties of moderate-sized particles because there are some effects (edge effect, surface wave interactions) that are not included in PGOM. As a result, my goal in my research project is to add the edge effect corrections to PGOM.” 

“Improving PGOM will improve our understanding in the role aerosol particles have in the Earth’s radiation budget,” she said.

The funded project is titled “A Study of the Optical Properties of Non-Spherical Particles with the Physical Geometric Optics Method,” and Okeudo’s advisor Dr. Ping Yang, atmospheric sciences professor and geosciences associate dean for research, will serve as principal investigator.

“I am very proud of Nancy’s achievements,” Yang said. “Her FINESST project is directed towards elevating our knowledge about the optical properties of dust aerosols. In particular, the proposed comparisons between theoretical simulations and satellite observations will aim at defining an optimal dust optical property model. Therefore, successful completion of the proposed work would lead to realistic optical properties of dust particles, which would benefit ground-based and spaceborne remote sensing of dust aerosol properties.”

The FINESST program reviewed a total of 789 proposals, with NASA’s Earth Science Division receiving 341 of those and selecting 62 for award, of which Okeudo's and Chao’s were two.

By Leslie Lee ’09