The Hong Kong University of Science and Technology (HKUST) Institute for the Environment (IENV) and the HKSAR Environmental Protection Department (HKEPD) recently announced a large-scale collaborative effort to study and develop science-based regional strategies to combat ozone and photochemical smog.
The project is led by HKEPD and carried out by atmospheric research teams from HKUST, Chinese University of Hong Kong (CUHK), City University of Hong Kong (CityU) and Hong Kong Polytechnic University (PolyU). This research collaboration also involves numerous international experts and atmospheric research teams, including those in Guangdong and Macao.
Combining multidisciplinary expertise and cutting-edge technology, it aims to improve the quantitative understanding of various emission sources that contribute to the formation of atmospheric ozone and smog, their transport routes, and their transformation processes en route via Hong Kong and the Guangdong-Hong Kong-Macao Greater Bay Area (GBA).
Over the past two decades, efforts by the Hong Kong, Macau and Guangdong governments to reduce emissions have resulted in significant reductions in ambient concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter (PM) values.
However, the average ozone concentration remains high and continues to increase. This issue has recently come to the fore as the Air Quality Health Index (AQHI) rises to Very High or Serious almost daily across the city, and ozone is the pollutant contributing most of the rise-long-term health risks that are reported by AQHI.
Accurately measuring these pollutants requires the use of advanced (research grade) instrumentation, backed by experienced researchers following carefully designed sampling and analysis protocols.
Therefore, the first part of the research effort is the continuous monitoring of the atmospheric composition of reactive organic precursors. This includes the operation of advanced continuous mass spectrometry instruments by research teams led by HKUST, CityU, CUHK and PolyU at multiple locations (urban, rural, background and Tai Mo Shan peak) to fully characterize the detailed composition of the ambient atmosphere around around Hong Kong.
Atmospheric transport is three-dimensional. In addition to quantifying the atmospheric composition on the ground, a good understanding of the atmospheric transport in the surface boundary layer above the ground is also very important. Therefore, the second part of the research effort is to operate LIDARs, led by HKUST, to continuously measure the vertical variations of wind, ozone and particulate matter (PM) at multiple locations in Hong Kong.
Ground and LIDAR measurements can provide continuous information at specific points, but spatial coverage remains limited. Therefore, the third part of the research effort is to do much more comprehensive air, sea and land measurements during episodic events.
These include advanced real-time sensor-based aerial surveillance and collection of multiple air samples from State Air Services helicopters led by HKUST researchers, aboard seagoing vessels led by another HKUST researcher, and through enhanced 80-point coordinated grid sampling conducted simultaneously in Hong Kong, Macau and Guangdong.
The expanded sampling implies a large increase in the need for precise VOC analysis, not only for the current Hong Kong research effort, but also for understanding and qualifying the increasing ozone problem in the GBA in the future. Therefore, the fourth part of the research effort is support from the HKEPD and the Innovation Technology Commission (ITC) for the establishment of a gold-standard VOC laboratory in Hong Kong, led by HKUST professors. This laboratory will serve as a reference laboratory to improve the region’s capacity for VOC measurement and analysis.
The observational data generated by the routine and episodic measurements will be analyzed by the initial research teams as well as the source attribution team led by a team from South China University of Technology, Guangzhou to help identify the dominant sources contributing to the release of the reactive precursors.
At the same time, the observations will also be used by an HKUST modeling team to refine and validate the air quality model for use in ozone and smog studies across Hong Kong and the GBA. Subsequently, based on the source attribution studies, the modeling team will also conduct scenario analysis to assess the performance of different emission control strategies in reducing ozone pollution in Hong Kong and the GBA.
The progress of this joint research will also be overseen by an 8-person Scientific Steering Committee of experts, which includes academic Prof. Jiming HAO (Tsinghua). Prof. Yuanhang ZHANG (PKU), Prof. Zifa WANG (Institute of Atmospheric Physics), Prof. XinMing WANG (Guangzhou Institute of Geochemistry), Prof. Junyu ZHENG (Jinan University), Prof. Yongbo ZHANG (Guangdong Provincial Academy of Environmental Sciences), Prof. Alexis LAU (HKUST) and Prof. Tao WANG (PolyU).
The Steering Committee meets at least once a year to review key findings and recommend potential updates and improvements in research methodology to ensure that the latest scientific evidence is considered and incorporated into this collaborative research effort.
Besides science, Prof. Alexis Lau urged the young researchers to appreciate the unique opportunity of participating in such a large, mission-oriented, multidisciplinary research project.