Ship emissions around China under gradually promoted control policies from 2016 to 2019

Abstract. Ship emissions and coastal air pollution around China are expected to be alleviated with the gradual implementation of ship domestic emission control area (DECA) policies. However, a comprehensive post-assessment on policy's effectiveness is still lacking. This study developed series high-spatiotemporal inventories from 2016 2019 based an updated Emission Inventory Model (SEIM v2.0) analyzed interannual changes in under influence both activity increases gradually promoted In this model, NOx, SO2, PM HC ships China's inland rivers 200 Nm (nautical miles) zone were estimated every day spatial resolution 0.05?×0.05? combination automatic identification system (AIS) data Technical Specifications Database (STSD). The route restoration technology classification ocean-going vessels (OGVs), (CVs) river (RVs) has greatly improved our model distribution emissions. From 2019, SO2 decreased by 29.6 % 26.4 %, respectively, while NOx increased 13.0 %. Although DECA 1.0 policy was implemented 2017, it not until when 2.0 came into effect that significant reduction achieved, e.g., year-on-year decrease 33.3 regarding SO2. Considering potential brought continuous growth maritime trade, however, even larger 39.8 achieved these 4 years compared scenario without switching cleaner fuel. Containers bulk carriers dominant contributors emissions, newly built, large using clean fuel oil account for increasingly proportion structures. A total consecutive daily presented major ports, which reflects step-by-step timely manner may provide useful references port observation experiments local making. addition, shows number detoured outside scope perhaps save costs more expensive low-sulfur oil, would increase farther areas. multiyear inventory provides high-quality datasets air-quality dispersion modeling, as well verifications situ experiments, also guide further directions China.