The booming of the economy in Hong Kong (HK) and the Pearl River Delta Economic Zone (PRD EZ) results in severe air pollution problems. Efficient data driven-based policy-making is of great importance in coping with the challenges. This thesis, with its focus on air quality modeling, applies the sensitivity analysis methodology to evaluate the effectiveness of integrated emission control policies and cross-boundary sectoral contributions to provide a holistic emission control potentials. A novel three-dimensional variational (3D-Var) coupled data fusion model is implemented to fusing hourly surface observations to investigate the Spatiotemporal variations of air pollution. This thesis study will illustrate three parts. Firstly, a new framework of refining production-based emissi...[ Read more ]

The booming of the economy in Hong Kong (HK) and the Pearl River Delta Economic Zone (PRD EZ) results in severe air pollution problems. Efficient data driven-based policy-making is of great importance in coping with the challenges. This thesis, with its focus on air quality modeling, applies the sensitivity analysis methodology to evaluate the effectiveness of integrated emission control policies and cross-boundary sectoral contributions to provide a holistic emission control potentials. A novel three-dimensional variational (3D-Var) coupled data fusion model is implemented to fusing hourly surface observations to investigate the Spatiotemporal variations of air pollution. This thesis study will illustrate three parts. Firstly, a new framework of refining production-based emission inventory is proposed to explore the yearlong Spatiotemporal variation of PM_2.5 and O₃ in HK and PRD EZ. Results of Spatiotemporal analysis confirm the model capability of reproducing the two-pollutant concentrations with the localized bottom-up emission inventory, including the automatic identification system (AIS) marine emission and real-time traffic data. Secondly, hypothetical dynamical scenario studies are carried out to evaluate China’s emission reduction policies in the 13^th Five-Year-Plan and short-term measures in HK. An integrated emission control potential map covering various emission sectors gradually extending to the whole of China is present for the first time. Calculating the health co-benefits of O₃ formation confirms the effectiveness of the control policies. Observing O₃ penalties due to the NOx-titration effect for calculating the co-benefits of emission control on concentration reduction call for simultaneously strengthened control on both NOx and VOC in the places with VOC-limited regime. The central government adopts the feasibility of tightening specific pollutants in HK using the scenario study from 2020 to 2025. Thirdly, A three-dimensional variational model coupled with a data fusion system was constructed to assess the spatiotemporal distribution of air pollutants. The impact of the data assimilation frequency on the improvement achieved by assimilation, multi-pollutant assimilation, and the benefits of assimilation are thoroughly explored. One pivotal finding is that assimilating air pollutants on the outermost domain brings substantial improvement of the PM_2.5 model simulations for the innermost domain, offering a potential alternative data fusion algorithm. The north-easterly wind bring the air pollutants along the coastline to the PRD water, so as to lift up the domain-wide assimilated air pollutants during the domestic-heating season. The coupled data fusion system could be a useful tool for improving air quality modeling systematic bias and diagnosing model deficiencies. Lastly, potential future research directions will be discussed, as well.