From Haze to Hope: Address Aerosol Pollution in Asia

Various types of pollution are causing hazardous effects globally. So why is Professor Gao Meng focusing his research on aerosol (tiny solid/liquid particles in a gas) pollution?

“About ten years ago, there was a severe haze episode of aerosol pollution in mainland China. And I was there,” said Professor Gao from the Department of Geography of HKBU. 

Professor Gao’s Research Journey

The January 2013 Beijing “Airpocalypse” marked the beginning of Professor Gao’s research journey in aerosol pollution. “Airpocalypse” was first used to describe that specific period when an unprecedented level of toxic smog covered parts of mainland China. This crisis resulted from human activities including burning fossil fuels, combined with atmospheric conditions that trapped pollutants. The resulting aerosols were like a thick blanket of smog, severely reducing visibility and posing serious health hazards to people.

Driven by such experience, Professor Gao investigated and found rich market research on aerosol pollution – But still, the understanding of the formation and impacts of aerosol pollution in Asia was limited. “There is vigorous economic development in some Asian countries. Aerosol pollution is and will remain an increasingly pressing issue in heavily populated countries, like India and mainland China,” said Professor Gao, an insightful and prescient researcher. He initiated his research journey focusing on aerosol pollution, particularly in mainland China, all the way through his PhD studies at the University of lowa and his post-doctoral studies at Harvard University.

Professor Gao’s Recent NSFC-Awarded Project

Professor Gao’s various research projects have been funded by the Research Grants Council (RGC) and the HKSAR government, including the Young Collaborative Research Grant (YCRG) and the Environment and Conservation Fund (ECF). Recently, one of his research projects titled “Numerical Modelling of the Formation of Aerosol and Its Interactions with Weather/Climate” was awarded the Excellent Young Scientists Fund (Hong Kong and Macau) 2023. It is a fund under the National Natural Science Foundation of China (NSFC), an organisation managed by the Ministry of Science and Technology.

New Industry Discovery: Brown Carbon Aerosols

It is known that aerosols have strong interactions with weather and climate change. Aerosol pollution is generated and developed from emissions and complex micro-chemical reactions, and macro-physical processes. Meanwhile, the atmospheric boundary layer, clouds, weather and climate processes are affected by aerosols through radiation effects. The interactions are presented below:

Interaction between aerosol-cloud-precipitation-climate

Aerosols in the atmosphere can be classified as black carbon and organic carbon. Black carbon warms the atmosphere by absorbing solar radiation, while organic carbon does the opposite. However, recent research shows some organic carbon also warms the atmosphere in a certain range of solar radiation (200-550nm). This carbon is called brown carbon, which comes from residential combustion, industry, etc. And this is the key element involved in Professor Gao’s NSFC-awarded project.  

Adding Brown Carbon to Numerical Model: Impact and Implications

In Professor Gao’s project, he aims at a better understanding of brown carbon in interactions between aerosol-weather-climate, while numerical modelling can depict the bi-direction of aerosol-weather-climate. Professor Gao will 1) add the characteristics of brown carbon to the existing numerical model of atmospheric chemistry to simulate air pollution better; 2) reveal the source and seasonal characteristics of brown carbon in mainland China; 3) reveal the effect of brown carbon radiation feedback on the occurrence and development of heavy haze in mainland China. These efforts contribute to understanding the effects of climate characteristics on aerosol pollution, which can help predict the severity of pollution occurrence and better plan pollution control measures.

Clear Skies Ahead: Collaboration for Success

This awarded project is an extension of Professor Gao’s previous studies and adjusted to be more related to the HKSAR government policies. With large uncertainties in the application of existing models for Asian countries, he must improve these models. He overcame such challenges by spending more time and effort with the experienced professional teams of HKBU researchers and collaborators from mainland China and the United States. 

Professor Gao will continue his existing collaboration with HKBU researchers with their expertise in computer science and biology. In the long term, he is planning to research into the aspects of urban environment, ozone pollution and urban heat island, to meet the needs of Hong Kong and the entire Greater Bay area.

“Sometimes it’s not easy to find a collaborator who works well with you. It’s good to expose yourselves to more opportunities to source for passionate researchers with a mutual interest with you,” Professor Gao stated his appreciation to his long-term collaborators, with whom he learnt and developed new research ideas.

About the Researcher

Professor Gao Meng is currently a Professor in the Department of Geography at HKBU. Before joining the University, he was a Postdoctoral Fellow at Harvard University (2016-2019). He received a Ph.D. in Chemical Engineering from the University of Iowa, USA, in 2015. His research interests include air quality modelling/forecasting, chemistry-climate interactions, environmental health, and artificial intelligence in atmospheric sciences. He has published more than 110 peer-reviewed papers in top-tier journals including Science Advances, PNAS, Nature Food and Nature Communications. He was awarded the Atmospheric Science Division Outstanding Young Scientist by EGU in 2020 and was invited to attend ACCESS XIV (14th Atmospheric Chemistry Colloquium for Emerging Senior Scientists) in 2017. He is also a member of the World Meteorological Organization Global Air Quality Forecasting and Information System (GAFIS) Steering Committee.

His research is motivated by a better understanding of processes that determine the spatiotemporal variations of air pollutants, and their implications for public health and climate. His research uses numerical atmospheric chemistry/weather/climate models (WRF-Chem, GEOS-Chem, WRF, CESM, etc.) and advanced statistical methods (machine learning, etc.) to interpret observed air pollution/climate phenomena, to assess their health impacts, and to prepare for the future.