The Hong Kong University of Science and Technology (HKUST)’s Institute for the Environment (IENV) and the HKSAR Environmental Protection Department (HKEPD) recently announced large-scale collaboration efforts to study and develop science-based regional ozone and photochemical smog control strategies.
The project will be led by the HKEPD and conducted by atmospheric research teams from HKUST, The Chinese University of Hong Kong (CUHK), the City University of Hong Kong (CityU) and The Hong Kong Polytechnic University (PolyU). This research collaboration effort also involves numerous international experts and atmospheric research teams including those in Guangdong and Macao.
By combining the use of multi-disciplinary expertise with cutting-edge technology, the aim is to enhance the quantitative understanding of different emission sources that contribute to the formation of ozone and smog in the atmosphere, their transport pathways and their enroute transformation processes over Hong Kong and the Guangdong-Hong Kong-Macao Greater Bay Area (GBA).
Over the last twenty years, the emission reduction efforts of the governments in Hong Kong, Macao, and Guangdong have resulted in significant reductions in the ambient concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2), and particulate matter (PM) levels.
However, the average concentration of ozone remains high and continues to increase. This issue has been bought to the fore recently, with the Air Quality Health Index (AQHI) going up to “Very High” or “Serious” all over the city almost every day, and ozone being the pollutant contributing to most of the increased short-term health risks reported by the AQHI.
The accurate measurement of these pollutants requires the use of advanced (research grade) instruments, supported by experienced researchers following carefully designed sampling and analysis protocols.
Hence, the first part of the research effort is the continuous monitoring of the atmospheric composition of the 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 at the top of Tai Mo Shan) to fully characterise the detailed composition of the ambient atmosphere around Hong Kong.
Atmospheric transport is three-dimensional. Besides 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. Hence, the second part of the research effort is the operation of LIDARs led by HKUST to continuously measure the vertical variations of wind, ozone, and particulate matter (PM) at multiple locations across Hong Kong.
Ground and LIDAR measurements can provide continuous information at specific points, but the spatial coverage continues to be limited. Hence, the third part of the research effort is to conduct much more comprehensive air, sea, and land measurements during episodic events.
These include the advanced real-time sensor-based air monitoring and collection of multiple air samples using helicopters from the Government Flying Services led by HKUST researchers, aboard marine vessels led by another HKUST researcher, and through enhanced 80-point simultaneous coordinated gridded sampling conducted in Hong Kong, Macao, and Guangdong.
The enhanced sampling implies a large increase in the need for precise VOC analyses, not just for the current research effort in Hong Kong, but also for understanding and qualifying the rising ozone problem in the GBA in the future. Hence, the fourth part of the research effort is the support by HKEPD and the Innovation Technology Commission (ITC) for the establishment of a Gold Standard VOC lab in Hong Kong led by HKUST professors. This lab is targeted to serve as a reference lab to help enhance the region’s capability in VOC measurements and analyses.
The observational data generated by the routine and episodic measurements shall be analysed by the initial research teams, as well as the source apportionment team led by a team from the South China University of Technology, Guangzhou to help identify the dominant sources contributing to the release of the reactive precursors.
Concurrently, the observations will also be used by an HKUST modelling team to fine-tune and validate the air quality model for use in ozone and smog studies over Hong Kong and the GBA. Subsequently, informed by the source apportionment studies, the modelling team shall also conduct scenario analyses to evaluate the performance of different emission control strategies in the reduction of ozone pollution in Hong Kong and the GBA.
The progress of this collaborative research is also closely monitored by an 8-member expert scientific steering committee including academician, Prof. Jiming HAO (Tsinghua), Academician. 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 the key findings and recommend potential updates and enhancements in the research methodologies, ensuring that the most up-to-date science is being considered and incorporated in this collaborative research effort.
Besides the science, Prof. Alexis Lau asked the young researchers to treasure the golden opportunity of participating in this type of large, mission-oriented, multi-disciplinary research project.