Improving the prediction of pollutant dispersion in urban areas Meet Nebila Lichiheb, Ph.D.

Growing up in Tunisia, Nebila Lichiheb inherited an interest in science from her father, who encouraged her to take as many classes in math and science as possible. Her affinity for STEM fields led her to pursue an engineering degree while attending the National Agronomic Institute of Tunisia, where she became fascinated with research on environmental sustainability in agricultural systems.

Nebila Lichiheb, Ph.D., conducted research to refine estimations of air pollution and assess risks to human health and the environment

Nebila Lichiheb, Ph.D., conducted research to refine estimations of air pollution and assess risks to human health and the environment. Photo Credit: Praveena Krishnan/NOAA ATDD

After moving to France and receiving her master’s in agroecology and her doctorate in environmental sciences from the French Institute for Education and Research in Agronomy, Environment, Life Science and Food Technology, Dr. Lichiheb joined the staff at the National Oceanic and Atmospheric Administration (NOAA) in 2016 as a research associate. Recently, Lichiheb conducted a research project focused on improving the prediction of pollutant dispersion in urban areas as part of a fellowship hosted by the Intelligence Community (IC) Postdoctoral Research Fellowship Program.

The IC Postdoc Program is administered by the Oak Ridge Institute for Science and Education (ORISE). The program offers scientists and engineers from a wide variety of disciplines unique opportunities to conduct research relevant to the Intelligence Community. For her appointment, Lichiheb was stationed in Oak Ridge, Tennessee with the Atmospheric Turbulence and Diffusion Division (ATDD) of the NOAA Air Resources Laboratory (ARL) located in Oak Ridge, Tennessee.

Under the guidance of her mentor, Dr. LaToya Myles, Deputy Director at NOAA ATDD, Lichiheb is conducting research in support of her research proposal “Improving the Prediction of Hazardous Material Dispersion in an Urban Environment.” Her project aims to refine estimations of air pollution and assess risks to human health and the environment. This involves optimizing the use of existing federal data to improve the modeling of pollutant dispersion in urban areas.

Lichiheb is specifically analyzing more than 10 years of data from the DCNet research network to improve the formulations of key variables, such as friction velocity, in controlling dispersion model calculations. DCNet was one of the first dispersion forecasting systems specifically designed for urban areas, and collects and analyzes meteorological data to help define areas of potentially high risk downwind, which could help protect the population from hazardous gases and/or particles dispersed into urban areas. Lichiheb’s proposed adjustments, based on her analysis of the DCNet data, will then be tested by implementing them into the HYSPLIT dispersion model to gauge how much the accuracy improved in predicting dispersion forecasts over Washington D.C. HYSPLIT was developed by NOAA ARL and designed to support a wide range of applications, from computing simple air parcel trajectories to complex transport and dispersion simulations.

A typical day for Lichiheb consists of collecting, describing and analyzing meteorological data, including both mean and turbulence observations. She then discusses the analyzed results with her team, tests several parameters in the HYSPLIT model and drafts reports and peer-reviewed articles to publish her results. Throughout the course of her fellowship, she is gaining new skills and knowledge on collecting, monitoring and analyzing meteorological data in urban areas.

When completed, Lichiheb’s research will help improve the capability to address all aspects of air pollution in urban areas, a need that continues to grow as urban populations rise.

“We are increasingly at risk due to hazardous emissions from both local sources and from noxious chemicals diverted from distant origins (e.g. pesticides). These risks are anticipated to increase as housing conditions, health care and infrastructure decline, all affected by climate change,” explained Lichiheb.

“By improving the dispersion models used to analyze and predict the transport and dispersion of hazardous contaminants, we will be able to better address health and safety concerns.”

Lichiheb is grateful for her experiences in the IC Postdoc Program and credits the collaboration and teamwork efforts she is involved in as her favorite part of her fellowship. She highly recommends the program to others, particularly women in STEM careers who are seeking new opportunities.

“I am very proud to have been selected for this award and to be part of this interesting program as a woman scientist,” said Lichiheb.

“Women in STEM have been fighting for equality for years, trying to have as many opportunities as males in award programs. Women are still highly under-represented in STEM and face unexamined assumptions that deter capable women from careers in the sciences. I have been through those challenges and they are pushing me to work harder to improve the status of women in science. I want to encourage girls who are interested in science to work hard, fulfil their dreams and reach positions of power in this field. I hope there are more working women scientists in the future.”

When her fellowship concludes, Lichiheb hopes to more deeply explore air quality issues in various ecosystems using both measurement and modeling approaches. She hopes to continue performing field measurements in several sites using several techniques and continue developing new parameterizations to better estimate air pollution.

The IC Postdoc Research Fellowship Program is administered by the Oak Ridge Institute for Science and Education (ORISE) under an agreement between the Office of the Director of National Intelligence (ODNI) and the U.S. Department of Energy (DOE). ORISE is managed for DOE by ORAU.