Baroclinicity in the Lower Atmosphere

2016 Faculty Research Award

Award Period: 2016-2018

Baroclinicity in the Lower Atmosphere
Pseudocolor plots of the vertical-velocity field over horizontal planes showing the changes in the structure of turbulent eddies due to baroclinicity. The top plot is a reference barotropic case; the middle is a simulation where baroclinicity induces a change in the pressure-gradient direction; and the bottom shows baroclinicity inducing a change (in this case a decrease in height) in the pressure-gradient magnitude.

Elie Bou-Zeid, associate professor of civil and environmental engineering, is receiving support to refine the fundamental understanding and models of the atmospheric boundary layer (ABL). The lowest one kilometer of the atmosphere, this layer is where humans live and where the atmosphere interacts with oceans and land. As such, a more systematic understanding of the ABL is crucial to creating accurate weather and climate predictions. Using large-eddy simulations, Bou-Zeid will explore how strong horizontal gradients in temperature that can lead to a state known as baroclinicity affect flow and transport in the ABL. The findings will improve our understanding of the lower atmosphere under realistic conditions, and lead to improvements in coarse models that will have a direct impact on weather forecasting, wind-energy forecasting, microclimatic studies (such as those over cities), surface-atmosphere interaction studies, and hydrometeorological modeling. Leo Donner, physical scientist at the Geophysical Fluid Dynamics Laboratory and lecturer in geosciences and Atmospheric and Oceanic Sciences, will collaborate on the project.

Educational Impacts

Bou-Zeid will provide opportunities for two undergraduates and one graduate student to collaborate on this research. The graduate student will conduct the large-eddy simulations. Once the numerical data are generated, undergraduate students can work as summer interns, or for their senior-thesis research, to, first, visualize coherent turbulent structures in the flow and examine how they are modulated by stability. A second project will be to develop a single-column model of baroclinic ABLs. Data sets from the project also will be incorporated into the undergraduate course “Environmental Fluid Mechanics” (CEE 305) and the graduate course “Boundary Layer Meteorology” (CEE 588).

Participating Department

Collaborating Institutions


Associate Professor of Civil and Environmental Engineering

Research Associates

  • Khaled Ghannam, CEE

Additional Researchers

Graduate Students

  • Mostafa Momen, CEE