Atmospheric Scientist Alumna Advances Sustainability Through Leading-Edge Air Quality Research

28 February 2022

Spurred by her School of Engineering student days to become an atmospheric scientist, alumna Prof. Sally Ng Nga-Lee is advancing sustainability through her leading air quality research, as well as fostering the next generation of aerosol explorers.

Clearing the air has had a special meaning for alumna Prof. Sally NG Nga-Lee ever since her days as a Chemical and Environmental Engineering undergraduate at the School of Engineering (SENG) 20 years ago. Indeed, she has gone on to make it her life’s work to contribute to improving global knowledge of air quality and its impact on human health and climate change.

Now a tenured Professor in the School of Chemical and Biomolecular Engineering at Georgia Institute of Technology in the US, with a joint appointment in the university’s School of Earth and Atmospheric Sciences and a courtesy appointment in the School of Civil and Environmental Engineering, the atmospheric scientist is opening up fresh horizons in her field by extending knowledge of fundamental chemical mechanisms related to the formation and composition of aerosols (fine particles suspended in air) through her research and teaching.

“My work allows me to explore the unknown, discover, and learn something new and exciting all the time”

Most recently, in October 2021, she and her inter-university team received US$12 million in grant money from the National Science Foundation in the US to generate high time-resolution (every 1 to 15 minutes), long-term measurements of aerosol properties. The work will be carried out via a network of 12 sites nationwide in a project officially known as the Atmospheric Science and Chemistry mEasurement NeTwork (ASCENT). The resulting data will assist understanding of how sustainability-based changes to electricity production and transportation are affecting air pollution and climate change variables.

In March 2021, she was among the scientists featured by the US’ National Oceanic and Atmospheric Administration (NOAA) for Women’s History Month, an annual international celebration of women’s contributions in history and contemporary society.

As Sally noted in the NOAA article: “I like that my work allows me to explore the unknown, discover, and learn something new and exciting all the time. I have the flexibility to pursue any research topics that I deeply care about.”

“Being a professor is the closest I can get to be a student forever”

In an email conversation with SENG, she also explained that she chose academia rather than a career as a researcher in industry or government as she really enjoys the enthusiasm and curiosity of students. “During my graduate studies and postdoctoral research, I had many opportunities to work with junior students. I found it very rewarding to be able to pass on my knowledge, learn new things, and grow with them. I enjoy learning and would have loved to be a student forever, and I think being a professor is the closest I can get to be a student forever.”

Interested in chemistry and mathematics in secondary school, Sally’s search for a university program combining these two subjects led her to SENG, which provides the only chemical engineering department at a Hong Kong university. When she received a positive response to her enquiries from then Department Head (now Professor Emeritus) YUE Po-Lock – “to my delight and surprise, Prof. Yue took the time to respond to my email and explain what chemical engineering was about” – and learned of the Chemical and Environmental Engineering bachelor’s degree, she decided to make it her major.

“The opportunity to participate in undergraduate research and the exchange program truly shaped my career path”

At SENG, Sally had the opportunity to participate in undergraduate research under the supervision of Prof. CHAN Chak-Keung, learning about aerosols and air quality. She also went on a one-year exchange to the University of Minnesota in the US, where she realized the air quality in Minnesota was much better than in Hong Kong. She then decided, with the encouragement and guidance of Prof. Chan, to apply for graduate programs in the US to learn more. “The opportunity to participate in undergraduate research and the exchange program truly shaped my career path,” she said.

Sally graduated from HKUST with a BEng in Chemical and Environmental Engineering (First Class) in 2002, moving on to a MS and PhD in Chemical Engineering at the California Institute of Technology (Caltech), and joining Georgia Institute of Technology in 2011 after three and a half years at a R&D company.

As an academic, she finds her life continually interesting and satisfying. “It is quite a lot of work to build a research program from scratch. But it is also very fulfilling and rewarding when things come together and to see the scientific, professional, and personal development of students over the years.”

“It’s important to choose what one loves to do. Then things will work out, one way or another”

She also recalled how on deciding that career path, she let passion for her subject guide her decision-making. “Back in those days, my decision to choose to major in chemical engineering in Hong Kong was perceived as an unconventional choice by many. But I think it’s important to choose what one loves to do. Then things will work out, one way or another.”

On her latest ASCENT project, she sees an advanced, long-term atmospheric aerosol network as critical in providing the measurements needed for informing science-based decisions on climate and environmental change. “We are very excited about this opportunity to establish ASCENT and we hope to strengthen collaborations with international atmospheric observation networks, including those in Asia,” she said.

Atmospheric Scientist Alumna Advances Sustainability Through Leading-Edge Air Quality Research

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