Researcher wins $366K grant to study environmental influences on southeastern clouds and storms

Sean Freeman
Dr. Sean Freeman, assistant professor in UAH’s Department of Atmospheric and Earth Science.
Michael Mercier | UAH

Dr. Sean Freeman, a researcher at The University of Alabama in Huntsville (UAH), has been awarded a $366,000 Department of Energy (DOE) grant to examine how atmospheric conditions such as winds, humidity, temperature and aerosols impact the growth of thunderstorms and the severe weather they produce within the Southeast. Dr. Freeman, an assistant professor in the College of Science at UAH, a part of the University of Alabama System, will be the principal investigator on the project. The federal funding will come through the DOE’s Office of Biological and Environmental Research.

The proposed research is a pilot study and will be performed using novel early observations provided by the deployment of the U.S. Department of Energy Atmospheric Radiation Measurement Mobile Facility-3 to North Alabama, a state-of-the-art cloud tracking algorithm called TOBAC for Tracking and Object-Based Analysis of Clouds, as well as high-resolution numerical model simulations. Both observations will examine how cloud lifetime and growth are impacted by changes in aerosol conditions when holding thermodynamics constant. The DOE is preparing to open the new North Alabama facility for atmospheric observations in the Bankhead National Forest.

“This past summer represents a perfect example of the need to perform this research,” Freeman notes. “Several days had poor air quality in North Alabama due to wildfire smoke transported from Canada and elsewhere. We need to better understand how this smoke, alongside other sources of particles in the atmosphere, influences clouds and their development to improve forecasts for Alabamians and enhance our ability to understand Earth's atmosphere.”

The research focuses on how local environmental conditions influence clouds and thunderstorms and the processes happening inside clouds to produce rain. The project will be using these new observations, alongside weather models and new algorithms, enabling researchers to track clouds and their conditions over time to understand the relationship between the temperature, humidity, winds and particles in the atmosphere and the clouds that are formed.

In the Southeastern United States, isolated thunderstorm clouds are ubiquitous throughout the year. These towering clouds are significant locally due to the severe weather they can produce, including flooding rainfall, making it vital to understand how they respond to the changing climate in the Southeast’s unique environment.

“I have always been interested in clouds, from small fair-weather cumulus clouds to towering cumulonimbus storm clouds,” Freeman says. “Isolated convective clouds, or small thunderstorm clouds, are critical to understand on a local scale, as they are prolific producers of severe weather.”